Class: RhaproxyFrontend

Inherits:
Object
  • Object
show all
Defined in:
lib/rhaproxy/frontend.rb

Overview

A “frontend” section describes a set of listening sockets accepting client connections.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ RhaproxyFrontend

Returns a new RhaproxyFrontend Object



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# File 'lib/rhaproxy/frontend.rb', line 2871

def initialize()
end

Instance Attribute Details

#acl ⇒ Object

acl <aclname> <criterion> [flags] [operator] <value> …

Declare or complete an access list.
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Example:
      acl invalid_src  src          0.0.0.0/7 224.0.0.0/3
      acl invalid_src  src_port     0:1023
      acl local_dst    hdr(host) -i localhost

See section 7 about ACL usage.



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# File 'lib/rhaproxy/frontend.rb', line 30

def acl
  @acl
end

#backlog ⇒ Object

backlog <conns>

Give hints to the system about the approximate listen backlog desired size
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments :
  <conns>   is the number of pending connections. Depending on the operating
            system, it may represent the number of already acknowledged

connections, of non-acknowledged ones, or both.

In order to protect against SYN flood attacks, one solution is to increase
the system's SYN backlog size. Depending on the system, sometimes it is just
tunable via a system parameter, sometimes it is not adjustable at all, and
sometimes the system relies on hints given by the application at the time of
the listen() syscall. By default, HAProxy passes the frontend's maxconn value
to the listen() syscall. On systems which can make use of this value, it can
sometimes be useful to be able to specify a different value, hence this
backlog parameter.

On Linux 2.4, the parameter is ignored by the system. On Linux 2.6, it is
used as a hint and the system accepts up to the smallest greater power of
two, and never more than some limits (usually 32768).

See also : "maxconn" and the target operating system's tuning guide.



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# File 'lib/rhaproxy/frontend.rb', line 1349

def backlog
  @backlog
end

#bind ⇒ Object

bind [<address>]:<port_range> [, …] bind [<address>]:<port_range> [, …] interface <interface> bind [<address>]:<port_range> [, …] mss <maxseg> bind [<address>]:<port_range> [, …] transparent bind [<address>]:<port_range> [, …] id <id> bind [<address>]:<port_range> [, …] name <name> bind [<address>]:<port_range> [, …] defer-accept bind [<address>]:<port_range> [, …] accept-proxy bind /<path> [, …] bind /<path> [, …] mode <mode> bind /<path> [, …] [ user <user> | uid <uid> ] bind /<path> [, …] [ group <user> | gid <gid> ]

Define one or several listening addresses and/or ports in a frontend.
May be used in sections :   defaults | frontend | listen | backend
                                no   |    yes   |   yes  |   no
Arguments :
  <address>     is optional and can be a host name, an IPv4 address, an IPv6
                address, or '*'. It designates the address the frontend will
                listen on. If unset, all IPv4 addresses of the system will be
                listened on. The same will apply for '*' or the system's
                special address "0.0.0.0".

  <port_range>  is either a unique TCP port, or a port range for which the
                proxy will accept connections for the IP address specified
                above. The port is mandatory for TCP listeners. Note that in
                the case of an IPv6 address, the port is always the number
                after the last colon (':'). A range can either be :
                 - a numerical port (ex: '80')
                 - a dash-delimited ports range explicitly stating the lower
                   and upper bounds (ex: '2000-2100') which are included in
                   the range.

                Particular care must be taken against port ranges, because
                every <address:port> couple consumes one socket (= a file
                descriptor), so it's easy to consume lots of descriptors
                with a simple range, and to run out of sockets. Also, each
                <address:port> couple must be used only once among all
                instances running on a same system. Please note that binding
                to ports lower than 1024 generally require particular
                privileges to start the program, which are independant of
                the 'uid' parameter.

  <path>        is a UNIX socket path beginning with a slash ('/'). This is
                alternative to the TCP listening port. Haproxy will then
                receive UNIX connections on the socket located at this place.
                The path must begin with a slash and by default is absolute.
                It can be relative to the prefix defined by "unix-bind" in
                the global section. Note that the total length of the prefix
                followed by the socket path cannot exceed some system limits
                for UNIX sockets, which commonly are set to 107 characters.

  <interface>   is an optional physical interface name. This is currently
                only supported on Linux. The interface must be a physical
                interface, not an aliased interface. When specified, all
                addresses on the same line will only be accepted if the
                incoming packet physically come through the designated
                interface. It is also possible to bind multiple frontends to
                the same address if they are bound to different interfaces.
                Note that binding to a physical interface requires root
                privileges. This parameter is only compatible with TCP
                sockets.

  <maxseg>      is an optional TCP Maximum Segment Size (MSS) value to be
                advertised on incoming connections. This can be used to force
                a lower MSS for certain specific ports, for instance for
                connections passing through a VPN. Note that this relies on a
                kernel feature which is theorically supported under Linux but
                was buggy in all versions prior to 2.6.28. It may or may not
                work on other operating systems. The commonly advertised
                value on Ethernet networks is 1460 = 1500(MTU) - 40(IP+TCP).
                This parameter is only compatible with TCP sockets.

  <id>          is a persistent value for socket ID. Must be positive and
                unique in the proxy. An unused value will automatically be
                assigned if unset. Can only be used when defining only a
                single socket.

  <name>        is an optional name provided for stats

  <mode>        is the octal mode used to define access permissions on the
                UNIX socket. It can also be set by default in the global
                section's "unix-bind" statement. Note that some platforms
                simply ignore this.

  <user>        is the name of user that will be marked owner of the UNIX
                socket.  It can also be set by default in the global
                section's "unix-bind" statement. Note that some platforms
                simply ignore this.

  <group>       is the name of a group that will be used to create the UNIX
                socket. It can also be set by default in the global section's
                "unix-bind" statement. Note that some platforms simply ignore
                this.

  <uid>         is the uid of user that will be marked owner of the UNIX
                socket. It can also be set by default in the global section's
                "unix-bind" statement. Note that some platforms simply ignore
                this.

  <gid>         is the gid of a group that will be used to create the UNIX
                socket. It can also be set by default in the global section's
                "unix-bind" statement. Note that some platforms simply ignore
                this.

  transparent   is an optional keyword which is supported only on certain
                Linux kernels. It indicates that the addresses will be bound
                even if they do not belong to the local machine. Any packet
                targeting any of these addresses will be caught just as if
                the address was locally configured. This normally requires
                that IP forwarding is enabled. Caution! do not use this with
                the default address '*', as it would redirect any traffic for
                the specified port. This keyword is available only when
                HAProxy is built with USE_LINUX_TPROXY=1. This parameter is
                only compatible with TCP sockets.

  defer-accept  is an optional keyword which is supported only on certain
                Linux kernels. It states that a connection will only be
                accepted once some data arrive on it, or at worst after the
                first retransmit. This should be used only on protocols for
                which the client talks first (eg: HTTP). It can slightly
                improve performance by ensuring that most of the request is
                already available when the connection is accepted. On the
                other hand, it will not be able to detect connections which
                don't talk. It is important to note that this option is
                broken in all kernels up to 2.6.31, as the connection is
                never accepted until the client talks. This can cause issues
                with front firewalls which would see an established
                connection while the proxy will only see it in SYN_RECV.

  accept-proxy  is an optional keyword which enforces use of the PROXY
                protocol over any connection accepted by this listener. The
                PROXY protocol dictates the layer 3/4 addresses of the
                incoming connection to be used everywhere an address is used,
                with the only exception of "tcp-request connection" rules
                which will only see the real connection address. Logs will
                reflect the addresses indicated in the protocol, unless it is
                violated, in which case the real address will still be used.
                This keyword combined with support from external components
                can be used as an efficient and reliable alternative to the
                X-Forwarded-For mechanism which is not always reliable and
                not even always usable.

It is possible to specify a list of address:port combinations delimited by
commas. The frontend will then listen on all of these addresses. There is no
fixed limit to the number of addresses and ports which can be listened on in
a frontend, as well as there is no limit to the number of "bind" statements
in a frontend.

Example :
      listen http_proxy
          bind :80,:443
          bind 10.0.0.1:10080,10.0.0.1:10443
          bind /var/run/ssl-frontend.sock user root mode 600 accept-proxy

See also : "source", "option forwardfor", "unix-bind" and the PROXY protocol
           documentation.



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# File 'lib/rhaproxy/frontend.rb', line 190

def bind
  @bind
end

#bind_process ⇒ Object

bind-process [ all | odd | even | <number 1-32> ] …

Limit visibility of an instance to a certain set of processes numbers.
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  all           All process will see this instance. This is the default. It
                may be used to override a default value.

  odd           This instance will be enabled on processes 1,3,5,...31. This
                option may be combined with other numbers.

  even          This instance will be enabled on processes 2,4,6,...32. This
                option may be combined with other numbers. Do not use it
                with less than 2 processes otherwise some instances might be
                missing from all processes.

  number        The instance will be enabled on this process number, between
                1 and 32. You must be careful not to reference a process
                number greater than the configured global.nbproc, otherwise
                some instances might be missing from all processes.

This keyword limits binding of certain instances to certain processes. This
is useful in order not to have too many processes listening to the same
ports. For instance, on a dual-core machine, it might make sense to set
'nbproc 2' in the global section, then distributes the listeners among 'odd'
and 'even' instances.

At the moment, it is not possible to reference more than 32 processes using
this keyword, but this should be more than enough for most setups. Please
note that 'all' really means all processes and is not limited to the first
32.

If some backends are referenced by frontends bound to other processes, the
backend automatically inherits the frontend's processes.

Example :
      listen app_ip1
          bind 10.0.0.1:80
          bind-process odd

      listen app_ip2
          bind 10.0.0.2:80
          bind-process even

      listen management
          bind 10.0.0.3:80
          bind-process 1 2 3 4

See also : "nbproc" in global section.



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# File 'lib/rhaproxy/frontend.rb', line 1402

def bind_process
  @bind_process
end

#block ⇒ Object

block { if | unless } <condition>

Block a layer 7 request if/unless a condition is matched
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes

The HTTP request will be blocked very early in the layer 7 processing
if/unless <condition> is matched. A 403 error will be returned if the request
is blocked. The condition has to reference ACLs (see section 7). This is
typically used to deny access to certain sensible resources if some
conditions are met or not met. There is no fixed limit to the number of
"block" statements per instance.

Example:
      acl invalid_src  src          0.0.0.0/7 224.0.0.0/3
      acl invalid_src  src_port     0:1023
      acl local_dst    hdr(host) -i localhost
      block if invalid_src || local_dst

See section 7 about ACL usage.



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# File 'lib/rhaproxy/frontend.rb', line 213

def block
  @block
end

#capture_cookie ⇒ Object

capture cookie <name> len <length>

Capture and log a cookie in the request and in the response.
May be used in sections :   defaults | frontend | listen | backend
                                no   |    yes   |   yes  |   no
Arguments :
  <name>    is the beginning of the name of the cookie to capture. In order
            to match the exact name, simply suffix the name with an equal
            sign ('='). The full name will appear in the logs, which is
            useful with application servers which adjust both the cookie name
            and value (eg: ASPSESSIONXXXXX).

  <length>  is the maximum number of characters to report in the logs, which
            include the cookie name, the equal sign and the value, all in the
            standard "name=value" form. The string will be truncated on the
            right if it exceeds <length>.

Only the first cookie is captured. Both the "cookie" request headers and the
"set-cookie" response headers are monitored. This is particularly useful to
check for application bugs causing session crossing or stealing between
users, because generally the user's cookies can only change on a login page.

When the cookie was not presented by the client, the associated log column
will report "-". When a request does not cause a cookie to be assigned by the
server, a "-" is reported in the response column.

The capture is performed in the frontend only because it is necessary that
the log format does not change for a given frontend depending on the
backends. This may change in the future. Note that there can be only one
"capture cookie" statement in a frontend. The maximum capture length is
configured in the sources by default to 64 characters. It is not possible to
specify a capture in a "defaults" section.

Example:
      capture cookie ASPSESSION len 32

See also : "capture request header", "capture response header" as well as
          section 8 about logging.



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# File 'lib/rhaproxy/frontend.rb', line 254

def capture_cookie
  @capture_cookie
end

#capture_request_header ⇒ Object

capture request header <name> len <length>

Capture and log the first occurrence of the specified request header.
May be used in sections :   defaults | frontend | listen | backend
                                no   |    yes   |   yes  |   no
Arguments :
  <name>    is the name of the header to capture. The header names are not
            case-sensitive, but it is a common practice to write them as they
            appear in the requests, with the first letter of each word in
            upper case. The header name will not appear in the logs, only the
            value is reported, but the position in the logs is respected.

  <length>  is the maximum number of characters to extract from the value and
            report in the logs. The string will be truncated on the right if
            it exceeds <length>.

Only the first value of the last occurrence of the header is captured. The
value will be added to the logs between braces ('{}'). If multiple headers
are captured, they will be delimited by a vertical bar ('|') and will appear
in the same order they were declared in the configuration. Non-existent
headers will be logged just as an empty string. Common uses for request
header captures include the "Host" field in virtual hosting environments, the
"Content-length" when uploads are supported, "User-agent" to quickly
differentiate between real users and robots, and "X-Forwarded-For" in proxied
environments to find where the request came from.

Note that when capturing headers such as "User-agent", some spaces may be
logged, making the log analysis more difficult. Thus be careful about what
you log if you know your log parser is not smart enough to rely on the
braces.

There is no limit to the number of captured request headers, but each capture
is limited to 64 characters. In order to keep log format consistent for a
same frontend, header captures can only be declared in a frontend. It is not
possible to specify a capture in a "defaults" section.

Example:
      capture request header Host len 15
      capture request header X-Forwarded-For len 15
      capture request header Referrer len 15

See also : "capture cookie", "capture response header" as well as section 8
           about logging.



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# File 'lib/rhaproxy/frontend.rb', line 300

def capture_request_header
  @capture_request_header
end

#capture_response_header ⇒ Object

capture response header <name> len <length>

Capture and log the first occurrence of the specified response header.
May be used in sections :   defaults | frontend | listen | backend
                                no   |    yes   |   yes  |   no
Arguments :
  <name>    is the name of the header to capture. The header names are not
            case-sensitive, but it is a common practice to write them as they
            appear in the response, with the first letter of each word in
            upper case. The header name will not appear in the logs, only the
            value is reported, but the position in the logs is respected.

  <length>  is the maximum number of characters to extract from the value and
            report in the logs. The string will be truncated on the right if
            it exceeds <length>.

Only the first value of the last occurrence of the header is captured. The
result will be added to the logs between braces ('{}') after the captured
request headers. If multiple headers are captured, they will be delimited by
a vertical bar ('|') and will appear in the same order they were declared in
the configuration. Non-existent headers will be logged just as an empty
string. Common uses for response header captures include the "Content-length"
header which indicates how many bytes are expected to be returned, the
"Location" header to track redirections.

There is no limit to the number of captured response headers, but each
capture is limited to 64 characters. In order to keep log format consistent
for a same frontend, header captures can only be declared in a frontend. It
is not possible to specify a capture in a "defaults" section.

Example:
      capture response header Content-length len 9
      capture response header Location len 15

See also : "capture cookie", "capture request header" as well as section 8
           about logging.



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# File 'lib/rhaproxy/frontend.rb', line 339

def capture_response_header
  @capture_response_header
end

#default_backend ⇒ Object

default_backend <backend>

Specify the backend to use when no "use_backend" rule has been matched.
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments :
  <backend> is the name of the backend to use.

When doing content-switching between frontend and backends using the
"use_backend" keyword, it is often useful to indicate which backend will be
used when no rule has matched. It generally is the dynamic backend which
will catch all undetermined requests.

Example :

      use_backend     dynamic  if  url_dyn
      use_backend     static   if  url_css url_img extension_img
      default_backend dynamic

See also : "use_backend", "reqsetbe", "reqisetbe"



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# File 'lib/rhaproxy/frontend.rb', line 1425

def default_backend
  @default_backend
end

#description ⇒ Object

description <text>

Add a text that describes the instance.

Please note that it is required to escape certain characters (# for example)
and this text is inserted into a html page so you should avoid using
"<" and ">" characters.



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# File 'lib/rhaproxy/frontend.rb', line 1322

def description
  @description
end

#disabled ⇒ Object

disabled

Disable a proxy, frontend or backend.
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

The "disabled" keyword is used to disable an instance, mainly in order to
liberate a listening port or to temporarily disable a service. The instance
will still be created and its configuration will be checked, but it will be
created in the "stopped" state and will appear as such in the statistics. It
will not receive any traffic nor will it send any health-checks or logs. It
is possible to disable many instances at once by adding the "disabled"
keyword in a "defaults" section.

See also : "enabled"



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# File 'lib/rhaproxy/frontend.rb', line 1444

def disabled
  @disabled
end

#enabled ⇒ Object

enabled

Enable a proxy, frontend or backend.
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

The "enabled" keyword is used to explicitly enable an instance, when the
defaults has been set to "disabled". This is very rarely used.

See also : "disabled"



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# File 'lib/rhaproxy/frontend.rb', line 1458

def enabled
  @enabled
end

#errorfile ⇒ Object

errorfile <code> <file>

Return a file contents instead of errors generated by HAProxy
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  <code>    is the HTTP status code. Currently, HAProxy is capable of
            generating codes 400, 403, 408, 500, 502, 503, and 504.

  <file>    designates a file containing the full HTTP response. It is
            recommended to follow the common practice of appending ".http" to
            the filename so that people do not confuse the response with HTML
            error pages, and to use absolute paths, since files are read
            before any chroot is performed.

It is important to understand that this keyword is not meant to rewrite
errors returned by the server, but errors detected and returned by HAProxy.
This is why the list of supported errors is limited to a small set.

The files are returned verbatim on the TCP socket. This allows any trick such
as redirections to another URL or site, as well as tricks to clean cookies,
force enable or disable caching, etc... The package provides default error
files returning the same contents as default errors.

The files should not exceed the configured buffer size (BUFSIZE), which
generally is 8 or 16 kB, otherwise they will be truncated. It is also wise
not to put any reference to local contents (eg: images) in order to avoid
loops between the client and HAProxy when all servers are down, causing an
error to be returned instead of an image. For better HTTP compliance, it is
recommended that all header lines end with CR-LF and not LF alone.

The files are read at the same time as the configuration and kept in memory.
For this reason, the errors continue to be returned even when the process is
chrooted, and no file change is considered while the process is running. A
simple method for developing those files consists in associating them to the
403 status code and interrogating a blocked URL.

See also : "errorloc", "errorloc302", "errorloc303"

Example :
      errorfile 400 /etc/haproxy/errorfiles/400badreq.http
      errorfile 403 /etc/haproxy/errorfiles/403forbid.http
      errorfile 503 /etc/haproxy/errorfiles/503sorry.http



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# File 'lib/rhaproxy/frontend.rb', line 1504

def errorfile
  @errorfile
end

#errorloc ⇒ Object

errorloc <code> <url>

Return an HTTP redirection to a URL instead of errors generated by HAProxy
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  <code>    is the HTTP status code. Currently, HAProxy is capable of
            generating codes 400, 403, 408, 500, 502, 503, and 504.

  <url>     it is the exact contents of the "Location" header. It may contain
            either a relative URI to an error page hosted on the same site,
            or an absolute URI designating an error page on another site.
            Special care should be given to relative URIs to avoid redirect
            loops if the URI itself may generate the same error (eg: 500).

It is important to understand that this keyword is not meant to rewrite
errors returned by the server, but errors detected and returned by HAProxy.
This is why the list of supported errors is limited to a small set.

Note that both keyword return the HTTP 302 status code, which tells the
client to fetch the designated URL using the same HTTP method. This can be
quite problematic in case of non-GET methods such as POST, because the URL
sent to the client might not be allowed for something other than GET. To
workaround this problem, please use "errorloc303" which send the HTTP 303
status code, indicating to the client that the URL must be fetched with a GET
request.

See also : "errorfile", "errorloc303"



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# File 'lib/rhaproxy/frontend.rb', line 1535

def errorloc
  @errorloc
end

#errorloc302 ⇒ Object

errorloc302 <code> <url>

Return an HTTP redirection to a URL instead of errors generated by HAProxy
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  <code>    is the HTTP status code. Currently, HAProxy is capable of
            generating codes 400, 403, 408, 500, 502, 503, and 504.

  <url>     it is the exact contents of the "Location" header. It may contain
            either a relative URI to an error page hosted on the same site,
            or an absolute URI designating an error page on another site.
            Special care should be given to relative URIs to avoid redirect
            loops if the URI itself may generate the same error (eg: 500).

It is important to understand that this keyword is not meant to rewrite
errors returned by the server, but errors detected and returned by HAProxy.
This is why the list of supported errors is limited to a small set.

Note that both keyword return the HTTP 302 status code, which tells the
client to fetch the designated URL using the same HTTP method. This can be
quite problematic in case of non-GET methods such as POST, because the URL
sent to the client might not be allowed for something other than GET. To
workaround this problem, please use "errorloc303" which send the HTTP 303
status code, indicating to the client that the URL must be fetched with a GET
request.

See also : "errorfile", "errorloc303"



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# File 'lib/rhaproxy/frontend.rb', line 1566

def errorloc302
  @errorloc302
end

#errorloc303 ⇒ Object

errorloc303 <code> <url>

Return an HTTP redirection to a URL instead of errors generated by HAProxy
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  <code>    is the HTTP status code. Currently, HAProxy is capable of
            generating codes 400, 403, 408, 500, 502, 503, and 504.

  <url>     it is the exact contents of the "Location" header. It may contain
            either a relative URI to an error page hosted on the same site,
            or an absolute URI designating an error page on another site.
            Special care should be given to relative URIs to avoid redirect
            loops if the URI itself may generate the same error (eg: 500).

It is important to understand that this keyword is not meant to rewrite
errors returned by the server, but errors detected and returned by HAProxy.
This is why the list of supported errors is limited to a small set.

Note that both keyword return the HTTP 303 status code, which tells the
client to fetch the designated URL using the same HTTP GET method. This
solves the usual problems associated with "errorloc" and the 302 code. It is
possible that some very old browsers designed before HTTP/1.1 do not support
it, but no such problem has been reported till now.

See also : "errorfile", "errorloc", "errorloc302"



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# File 'lib/rhaproxy/frontend.rb', line 1595

def errorloc303
  @errorloc303
end

#force_persist ⇒ Object

force-persist { if | unless } <condition>

Declare a condition to force persistence on down servers
May be used in sections:    defaults | frontend | listen | backend
                                no   |    yes   |   yes  |   yes

By default, requests are not dispatched to down servers. It is possible to
force this using "option persist", but it is unconditional and redispatches
to a valid server if "option redispatch" is set. That leaves with very little
possibilities to force some requests to reach a server which is artificially
marked down for maintenance operations.

The "force-persist" statement allows one to declare various ACL-based
conditions which, when met, will cause a request to ignore the down status of
a server and still try to connect to it. That makes it possible to start a
server, still replying an error to the health checks, and run a specially
configured browser to test the service. Among the handy methods, one could
use a specific source IP address, or a specific cookie. The cookie also has
the advantage that it can easily be added/removed on the browser from a test
page. Once the service is validated, it is then possible to open the service
to the world by returning a valid response to health checks.

The forced persistence is enabled when an "if" condition is met, or unless an
"unless" condition is met. The final redispatch is always disabled when this
is used.

See also : "option redispatch", "ignore-persist", "persist",
           and section 7 about ACL usage.



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# File 'lib/rhaproxy/frontend.rb', line 370

def force_persist
  @force_persist
end

#grace ⇒ Object

grace <time>

Maintain a proxy operational for some time after a soft stop
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  <time>    is the time (by default in milliseconds) for which the instance
            will remain operational with the frontend sockets still listening
            when a soft-stop is received via the SIGUSR1 signal.

This may be used to ensure that the services disappear in a certain order.
This was designed so that frontends which are dedicated to monitoring by an
external equipment fail immediately while other ones remain up for the time
needed by the equipment to detect the failure.

Note that currently, there is very little benefit in using this parameter,
and it may in fact complicate the soft-reconfiguration process more than
simplify it.



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# File 'lib/rhaproxy/frontend.rb', line 1616

def grace
  @grace
end

#http_request ⇒ Object

http-request { allow | deny | auth [realm <realm>] }

           [ { if | unless } <condition> ]
Access control for Layer 7 requests

May be used in sections:   defaults | frontend | listen | backend
                              no    |    yes   |   yes  |   yes

These set of options allow to fine control access to a
frontend/listen/backend. Each option may be followed by if/unless and acl.
First option with matched condition (or option without condition) is final.
For "deny" a 403 error will be returned, for "allow" normal processing is
performed, for "auth" a 401/407 error code is returned so the client
should be asked to enter a username and password.

There is no fixed limit to the number of http-request statements per
instance.

Example:
      acl nagios src 192.168.129.3
      acl local_net src 192.168.0.0/16
      acl auth_ok http_auth(L1)

      http-request allow if nagios
      http-request allow if local_net auth_ok
      http-request auth realm Gimme if local_net auth_ok
      http-request deny

Example:
      acl auth_ok http_auth_group(L1) G1

      http-request auth unless auth_ok

See also : "stats http-request", section 3.4 about userlists and section 7
           about ACL usage.



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# File 'lib/rhaproxy/frontend.rb', line 408

def http_request
  @http_request
end

#ignore_persist ⇒ Object

ignore-persist { if | unless } <condition>

Declare a condition to ignore persistence
May be used in sections:    defaults | frontend | listen | backend
                                no   |    yes   |   yes  |   yes

By default, when cookie persistence is enabled, every requests containing
the cookie are unconditionally persistent (assuming the target server is up
and running).

The "ignore-persist" statement allows one to declare various ACL-based
conditions which, when met, will cause a request to ignore persistence.
This is sometimes useful to load balance requests for static files, which
oftenly don't require persistence. This can also be used to fully disable
persistence for a specific User-Agent (for example, some web crawler bots).

Combined with "appsession", it can also help reduce HAProxy memory usage, as
the appsession table won't grow if persistence is ignored.

The persistence is ignored when an "if" condition is met, or unless an
"unless" condition is met.

See also : "force-persist", "cookie", and section 7 about ACL usage.



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# File 'lib/rhaproxy/frontend.rb', line 446

def ignore_persist
  @ignore_persist
end

#log ⇒ Object

log global log <address> <facility> [<level> [<minlevel>]]

Enable per-instance logging of events and traffic.
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  global     should be used when the instance's logging parameters are the
             same as the global ones. This is the most common usage. "global"
             replaces <address>, <facility> and <level> with those of the log
             entries found in the "global" section. Only one "log global"
             statement may be used per instance, and this form takes no other
             parameter.

  <address>  indicates where to send the logs. It takes the same format as
             for the "global" section's logs, and can be one of :

             - An IPv4 address optionally followed by a colon (':') and a UDP
               port. If no port is specified, 514 is used by default (the
               standard syslog port).

             - A filesystem path to a UNIX domain socket, keeping in mind
               considerations for chroot (be sure the path is accessible
               inside the chroot) and uid/gid (be sure the path is
               appropriately writeable).

  <facility> must be one of the 24 standard syslog facilities :

               kern   user   mail   daemon auth   syslog lpr    news
               uucp   cron   auth2  ftp    ntp    audit  alert  cron2
               local0 local1 local2 local3 local4 local5 local6 local7

  <level>    is optional and can be specified to filter outgoing messages. By
             default, all messages are sent. If a level is specified, only
             messages with a severity at least as important as this level
             will be sent. An optional minimum level can be specified. If it
             is set, logs emitted with a more severe level than this one will
             be capped to this level. This is used to avoid sending "emerg"
             messages on all terminals on some default syslog configurations.
             Eight levels are known :

               emerg  alert  crit   err    warning notice info  debug

Note that up to two "log" entries may be specified per instance. However, if
"log global" is used and if the "global" section already contains 2 log
entries, then additional log entries will be ignored.

Also, it is important to keep in mind that it is the frontend which decides
what to log from a connection, and that in case of content switching, the log
entries from the backend will be ignored. Connections are logged at level
"info".

However, backend log declaration define how and where servers status changes
will be logged. Level "notice" will be used to indicate a server going up,
"warning" will be used for termination signals and definitive service
termination, and "alert" will be used for when a server goes down.

Note : According to RFC3164, messages are truncated to 1024 bytes before
       being emitted.

Example :
  log global
  log 127.0.0.1:514 local0 notice         # only send important events
  log 127.0.0.1:514 local0 notice notice  # same but limit output level



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# File 'lib/rhaproxy/frontend.rb', line 1682

def log
  @log
end

#maxconn ⇒ Object

maxconn <conns>

Fix the maximum number of concurrent connections on a frontend
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments :
  <conns>   is the maximum number of concurrent connections the frontend will
            accept to serve. Excess connections will be queued by the system
            in the socket's listen queue and will be served once a connection
            closes.

If the system supports it, it can be useful on big sites to raise this limit
very high so that haproxy manages connection queues, instead of leaving the
clients with unanswered connection attempts. This value should not exceed the
global maxconn. Also, keep in mind that a connection contains two buffers
of 8kB each, as well as some other data resulting in about 17 kB of RAM being
consumed per established connection. That means that a medium system equipped
with 1GB of RAM can withstand around 40000-50000 concurrent connections if
properly tuned.

Also, when <conns> is set to large values, it is possible that the servers
are not sized to accept such loads, and for this reason it is generally wise
to assign them some reasonable connection limits.

See also : "server", global section's "maxconn", "fullconn"



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# File 'lib/rhaproxy/frontend.rb', line 1710

def maxconn
  @maxconn
end

#mode ⇒ Object

mode { tcp|http|health }

Set the running mode or protocol of the instance
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  tcp       The instance will work in pure TCP mode. A full-duplex connection
            will be established between clients and servers, and no layer 7
            examination will be performed. This is the default mode. It
            should be used for SSL, SSH, SMTP, ...

  http      The instance will work in HTTP mode. The client request will be
            analyzed in depth before connecting to any server. Any request
            which is not RFC-compliant will be rejected. Layer 7 filtering,
            processing and switching will be possible. This is the mode which
            brings HAProxy most of its value.

  health    The instance will work in "health" mode. It will just reply "OK"
            to incoming connections and close the connection. Nothing will be
            logged. This mode is used to reply to external components health
            checks. This mode is deprecated and should not be used anymore as
            it is possible to do the same and even better by combining TCP or
            HTTP modes with the "monitor" keyword.

 When doing content switching, it is mandatory that the frontend and the
 backend are in the same mode (generally HTTP), otherwise the configuration
 will be refused.

 Example :
   defaults http_instances
       mode http

 See also : "monitor", "monitor-net"



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# File 'lib/rhaproxy/frontend.rb', line 1746

def mode
  @mode
end

#monitor_fail ⇒ Object

monitor fail { if | unless } <condition>

Add a condition to report a failure to a monitor HTTP request.
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   no
Arguments :
  if <cond>     the monitor request will fail if the condition is satisfied,
                and will succeed otherwise. The condition should describe a
                combined test which must induce a failure if all conditions
                are met, for instance a low number of servers both in a
                backend and its backup.

  unless <cond> the monitor request will succeed only if the condition is
                satisfied, and will fail otherwise. Such a condition may be
                based on a test on the presence of a minimum number of active
                servers in a list of backends.

This statement adds a condition which can force the response to a monitor
request to report a failure. By default, when an external component queries
the URI dedicated to monitoring, a 200 response is returned. When one of the
conditions above is met, haproxy will return 503 instead of 200. This is
very useful to report a site failure to an external component which may base
routing advertisements between multiple sites on the availability reported by
haproxy. In this case, one would rely on an ACL involving the "nbsrv"
criterion. Note that "monitor fail" only works in HTTP mode.

Example:
   frontend www
      mode http
      acl site_dead nbsrv(dynamic) lt 2
      acl site_dead nbsrv(static)  lt 2
      monitor-uri   /site_alive
      monitor fail  if site_dead

See also : "monitor-net", "monitor-uri"



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# File 'lib/rhaproxy/frontend.rb', line 484

def monitor_fail
  @monitor_fail
end

#monitor_net ⇒ Object

monitor-net <source>

Declare a source network which is limited to monitor requests
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments :
  <source>  is the source IPv4 address or network which will only be able to
            get monitor responses to any request. It can be either an IPv4
            address, a host name, or an address followed by a slash ('/')
            followed by a mask.

In TCP mode, any connection coming from a source matching <source> will cause
the connection to be immediately closed without any log. This allows another
equipment to probe the port and verify that it is still listening, without
forwarding the connection to a remote server.

In HTTP mode, a connection coming from a source matching <source> will be
accepted, the following response will be sent without waiting for a request,
then the connection will be closed : "HTTP/1.0 200 OK". This is normally
enough for any front-end HTTP probe to detect that the service is UP and
running without forwarding the request to a backend server.

Monitor requests are processed very early. It is not possible to block nor
divert them using ACLs. They cannot be logged either, and it is the intended
purpose. They are only used to report HAProxy's health to an upper component,
nothing more. Right now, it is not possible to set failure conditions on
requests caught by "monitor-net".

Last, please note that only one "monitor-net" statement can be specified in
a frontend. If more than one is found, only the last one will be considered.

Example :
  # addresses .252 and .253 are just probing us.
  frontend www
      monitor-net 192.168.0.252/31

See also : "monitor fail", "monitor-uri"



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# File 'lib/rhaproxy/frontend.rb', line 1786

def monitor_net
  @monitor_net
end

#monitor_uri ⇒ Object

monitor-uri <uri>

Intercept a URI used by external components' monitor requests
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments :
  <uri>     is the exact URI which we want to intercept to return HAProxy's
            health status instead of forwarding the request.

When an HTTP request referencing <uri> will be received on a frontend,
HAProxy will not forward it nor log it, but instead will return either
"HTTP/1.0 200 OK" or "HTTP/1.0 503 Service unavailable", depending on failure
conditions defined with "monitor fail". This is normally enough for any
front-end HTTP probe to detect that the service is UP and running without
forwarding the request to a backend server. Note that the HTTP method, the
version and all headers are ignored, but the request must at least be valid
at the HTTP level. This keyword may only be used with an HTTP-mode frontend.

Monitor requests are processed very early. It is not possible to block nor
divert them using ACLs. They cannot be logged either, and it is the intended
purpose. They are only used to report HAProxy's health to an upper component,
nothing more. However, it is possible to add any number of conditions using
"monitor fail" and ACLs so that the result can be adjusted to whatever check
can be imagined (most often the number of available servers in a backend).

Example :
  # Use /haproxy_test to report haproxy's status
  frontend www
      mode http
      monitor-uri /haproxy_test

See also : "monitor fail", "monitor-net"



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# File 'lib/rhaproxy/frontend.rb', line 1821

def monitor_uri
  @monitor_uri
end

#name ⇒ Object

name <name>

The frontend name is required.



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# File 'lib/rhaproxy/frontend.rb', line 2866

def name
  @name
end

#option_accept_invalid_http_request ⇒ Object

option accept-invalid-http-request no option accept-invalid-http-request

Enable or disable relaxing of HTTP request parsing
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments : none

By default, HAProxy complies with RFC2616 in terms of message parsing. This
means that invalid characters in header names are not permitted and cause an
error to be returned to the client. This is the desired behaviour as such
forbidden characters are essentially used to build attacks exploiting server
weaknesses, and bypass security filtering. Sometimes, a buggy browser or
server will emit invalid header names for whatever reason (configuration,
implementation) and the issue will not be immediately fixed. In such a case,
it is possible to relax HAProxy's header name parser to accept any character
even if that does not make sense, by specifying this option.

This option should never be enabled by default as it hides application bugs
and open security breaches. It should only be deployed after a problem has
been confirmed.

When this option is enabled, erroneous header names will still be accepted in
requests, but the complete request will be captured in order to permit later
analysis using the "show errors" request on the UNIX stats socket. Doing this
also helps confirming that the issue has been solved.

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.

See also : "option accept-invalid-http-response" and "show errors" on the
           stats socket.



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# File 'lib/rhaproxy/frontend.rb', line 1856

def option_accept_invalid_http_request
  @option_accept_invalid_http_request
end

#option_clitcpka ⇒ Object

option clitcpka no option clitcpka

Enable or disable the sending of TCP keepalive packets on the client side
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments : none

When there is a firewall or any session-aware component between a client and
a server, and when the protocol involves very long sessions with long idle
periods (eg: remote desktops), there is a risk that one of the intermediate
components decides to expire a session which has remained idle for too long.

Enabling socket-level TCP keep-alives makes the system regularly send packets
to the other end of the connection, leaving it active. The delay between
keep-alive probes is controlled by the system only and depends both on the
operating system and its tuning parameters.

It is important to understand that keep-alive packets are neither emitted nor
received at the application level. It is only the network stacks which sees
them. For this reason, even if one side of the proxy already uses keep-alives
to maintain its connection alive, those keep-alive packets will not be
forwarded to the other side of the proxy.

Please note that this has nothing to do with HTTP keep-alive.

Using option "clitcpka" enables the emission of TCP keep-alive probes on the
client side of a connection, which should help when session expirations are
noticed between HAProxy and a client.

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.

See also : "option srvtcpka", "option tcpka"



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# File 'lib/rhaproxy/frontend.rb', line 1893

def option_clitcpka
  @option_clitcpka
end

#option_contstats ⇒ Object

option contstats

Enable continuous traffic statistics updates
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments : none

By default, counters used for statistics calculation are incremented
only when a session finishes. It works quite well when serving small
objects, but with big ones (for example large images or archives) or
with A/V streaming, a graph generated from haproxy counters looks like
a hedgehog. With this option enabled counters get incremented continuously,
during a whole session. Recounting touches a hotpath directly so
it is not enabled by default, as it has small performance impact (~0.5%).



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# File 'lib/rhaproxy/frontend.rb', line 1910

def option_contstats
  @option_contstats
end

#option_dontlog_normal ⇒ Object

option dontlog-normal no option dontlog-normal

Enable or disable logging of normal, successful connections
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments : none

There are large sites dealing with several thousand connections per second
and for which logging is a major pain. Some of them are even forced to turn
logs off and cannot debug production issues. Setting this option ensures that
normal connections, those which experience no error, no timeout, no retry nor
redispatch, will not be logged. This leaves disk space for anomalies. In HTTP
mode, the response status code is checked and return codes 5xx will still be
logged.

It is strongly discouraged to use this option as most of the time, the key to
complex issues is in the normal logs which will not be logged here. If you
need to separate logs, see the "log-separate-errors" option instead.

See also : "log", "dontlognull", "log-separate-errors" and section 8 about
           logging.



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# File 'lib/rhaproxy/frontend.rb', line 1935

def option_dontlog_normal
  @option_dontlog_normal
end

#option_dontlognull ⇒ Object

option dontlognull no option dontlognull

Enable or disable logging of null connections
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments : none

In certain environments, there are components which will regularly connect to
various systems to ensure that they are still alive. It can be the case from
another load balancer as well as from monitoring systems. By default, even a
simple port probe or scan will produce a log. If those connections pollute
the logs too much, it is possible to enable option "dontlognull" to indicate
that a connection on which no data has been transferred will not be logged,
which typically corresponds to those probes.

It is generally recommended not to use this option in uncontrolled
environments (eg: internet), otherwise scans and other malicious activities
would not be logged.

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.

See also : "log", "monitor-net", "monitor-uri" and section 8 about logging.



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# File 'lib/rhaproxy/frontend.rb', line 1962

def option_dontlognull
  @option_dontlognull
end

#option_forceclose ⇒ Object

option forceclose no option forceclose

Enable or disable active connection closing after response is transferred.
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

Some HTTP servers do not necessarily close the connections when they receive
the "Connection: close" set by "option httpclose", and if the client does not
close either, then the connection remains open till the timeout expires. This
causes high number of simultaneous connections on the servers and shows high
global session times in the logs.

When this happens, it is possible to use "option forceclose". It will
actively close the outgoing server channel as soon as the server has finished
to respond. This option implicitly enables the "httpclose" option. Note that
this option also enables the parsing of the full request and response, which
means we can close the connection to the server very quickly, releasing some
resources earlier than with httpclose.

This option may also be combined with "option http-pretend-keepalive", which
will disable sending of the "Connection: close" header, but will still cause
the connection to be closed once the whole response is received.

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.

See also : "option httpclose" and "option http-pretend-keepalive"



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# File 'lib/rhaproxy/frontend.rb', line 1994

def option_forceclose
  @option_forceclose
end

#option_forwardfor ⇒ Object

option forwardfor [ except <network> ] [ header <name> ]

Enable insertion of the X-Forwarded-For header to requests sent to servers
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  <network> is an optional argument used to disable this option for sources
            matching <network>
  <name>    an optional argument to specify a different "X-Forwarded-For"
            header name.

Since HAProxy works in reverse-proxy mode, the servers see its IP address as
their client address. This is sometimes annoying when the client's IP address
is expected in server logs. To solve this problem, the well-known HTTP header
"X-Forwarded-For" may be added by HAProxy to all requests sent to the server.
This header contains a value representing the client's IP address. Since this
header is always appended at the end of the existing header list, the server
must be configured to always use the last occurrence of this header only. See
the server's manual to find how to enable use of this standard header. Note
that only the last occurrence of the header must be used, since it is really
possible that the client has already brought one.

The keyword "header" may be used to supply a different header name to replace
the default "X-Forwarded-For". This can be useful where you might already
have a "X-Forwarded-For" header from a different application (eg: stunnel),
and you need preserve it. Also if your backend server doesn't use the
"X-Forwarded-For" header and requires different one (eg: Zeus Web Servers
require "X-Cluster-Client-IP").

Sometimes, a same HAProxy instance may be shared between a direct client
access and a reverse-proxy access (for instance when an SSL reverse-proxy is
used to decrypt HTTPS traffic). It is possible to disable the addition of the
header for a known source address or network by adding the "except" keyword
followed by the network address. In this case, any source IP matching the
network will not cause an addition of this header. Most common uses are with
private networks or 127.0.0.1.

This option may be specified either in the frontend or in the backend. If at
least one of them uses it, the header will be added. Note that the backend's
setting of the header subargument takes precedence over the frontend's if
both are defined.

It is important to note that as long as HAProxy does not support keep-alive
connections, only the first request of a connection will receive the header.
For this reason, it is important to ensure that "option httpclose" is set
when using this option.

Examples :
  # Public HTTP address also used by stunnel on the same machine
  frontend www
      mode http
      option forwardfor except 127.0.0.1  # stunnel already adds the header

  # Those servers want the IP Address in X-Client
  backend www
      mode http
      option forwardfor header X-Client

See also : "option httpclose"



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# File 'lib/rhaproxy/frontend.rb', line 2056

def option_forwardfor
  @option_forwardfor
end

#option_http_pretend_keepalive ⇒ Object

option http-pretend-keepalive no option http-pretend-keepalive

Define whether haproxy will announce keepalive to the server or not
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

When running with "option http-server-close" or "option forceclose", haproxy
adds a "Connection: close" header to the request forwarded to the server.
Unfortunately, when some servers see this header, they automatically refrain
from using the chunked encoding for responses of unknown length, while this
is totally unrelated. The immediate effect is that this prevents haproxy from
maintaining the client connection alive. A second effect is that a client or
a cache could receive an incomplete response without being aware of it, and
consider the response complete.

By setting "option http-pretend-keepalive", haproxy will make the server
believe it will keep the connection alive. The server will then not fall back
to the abnormal undesired above. When haproxy gets the whole response, it
will close the connection with the server just as it would do with the
"forceclose" option. That way the client gets a normal response and the
connection is correctly closed on the server side.

It is recommended not to enable this option by default, because most servers
will more efficiently close the connection themselves after the last packet,
and release its buffers slightly earlier. Also, the added packet on the
network could slightly reduce the overall peak performance. However it is
worth noting that when this option is enabled, haproxy will have slightly
less work to do. So if haproxy is the bottleneck on the whole architecture,
enabling this option might save a few CPU cycles.

This option may be set both in a frontend and in a backend. It is enabled if
at least one of the frontend or backend holding a connection has it enabled.
This option may be compbined with "option httpclose", which will cause
keepalive to be announced to the server and close to be announced to the
client. This practice is discouraged though.

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.

See also : "option forceclose" and "option http-server-close"



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# File 'lib/rhaproxy/frontend.rb', line 2101

def option_http_pretend_keepalive
  @option_http_pretend_keepalive
end

#option_http_proxy ⇒ Object

option http_proxy no option http_proxy

Enable or disable plain HTTP proxy mode
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

It sometimes happens that people need a pure HTTP proxy which understands
basic proxy requests without caching nor any fancy feature. In this case,
it may be worth setting up an HAProxy instance with the "option http_proxy"
set. In this mode, no server is declared, and the connection is forwarded to
the IP address and port found in the URL after the "http://" scheme.

No host address resolution is performed, so this only works when pure IP
addresses are passed. Since this option's usage perimeter is rather limited,
it will probably be used only by experts who know they need exactly it. Last,
if the clients are susceptible of sending keep-alive requests, it will be
needed to add "option http_close" to ensure that all requests will correctly
be analyzed.

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.

Example :
  # this backend understands HTTP proxy requests and forwards them directly.
  backend direct_forward
      option httpclose
      option http_proxy

See also : "option httpclose"



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# File 'lib/rhaproxy/frontend.rb', line 2282

def option_http_proxy
  @option_http_proxy
end

#option_http_server_close ⇒ Object

option http-server-close no option http-server-close

Enable or disable HTTP connection closing on the server side
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

By default, when a client communicates with a server, HAProxy will only
analyze, log, and process the first request of each connection. Setting
"option http-server-close" enables HTTP connection-close mode on the server
side while keeping the ability to support HTTP keep-alive and pipelining on
the client side.  This provides the lowest latency on the client side (slow
network) and the fastest session reuse on the server side to save server
resources, similarly to "option forceclose". It also permits non-keepalive
capable servers to be served in keep-alive mode to the clients if they
conform to the requirements of RFC2616. Please note that some servers do not
always conform to those requirements when they see "Connection: close" in the
request. The effect will be that keep-alive will never be used. A workaround
consists in enabling "option http-pretend-keepalive".

At the moment, logs will not indicate whether requests came from the same
session or not. The accept date reported in the logs corresponds to the end
of the previous request, and the request time corresponds to the time spent
waiting for a new request. The keep-alive request time is still bound to the
timeout defined by "timeout http-keep-alive" or "timeout http-request" if
not set.

This option may be set both in a frontend and in a backend. It is enabled if
at least one of the frontend or backend holding a connection has it enabled.
It is worth noting that "option forceclose" has precedence over "option
http-server-close" and that combining "http-server-close" with "httpclose"
basically achieve the same result as "forceclose".

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.

See also : "option forceclose", "option http-pretend-keepalive",
           "option httpclose" and "1.1. The HTTP transaction model".



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# File 'lib/rhaproxy/frontend.rb', line 2143

def option_http_server_close
  @option_http_server_close
end

#option_http_use_proxy_header ⇒ Object

option http-use-proxy-header no option http-use-proxy-header

Make use of non-standard Proxy-Connection header instead of Connection
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments : none

While RFC2616 explicitly states that HTTP/1.1 agents must use the
Connection header to indicate their wish of persistent or non-persistent
connections, both browsers and proxies ignore this header for proxied
connections and make use of the undocumented, non-standard Proxy-Connection
header instead. The issue begins when trying to put a load balancer between
browsers and such proxies, because there will be a difference between what
haproxy understands and what the client and the proxy agree on.

By setting this option in a frontend, haproxy can automatically switch to use
that non-standard header if it sees proxied requests. A proxied request is
defined here as one where the URI begins with neither a '/' nor a '*'. The
choice of header only affects requests passing through proxies making use of
one of the "httpclose", "forceclose" and "http-server-close" options. Note
that this option can only be specified in a frontend and will affect the
request along its whole life.

Also, when this option is set, a request which requires authentication will
automatically switch to use proxy authentication headers if it is itself a
proxied request. That makes it possible to check or enforce authentication in
front of an existing proxy.

This option should normally never be used, except in front of a proxy.

See also : "option httpclose", "option forceclose" and "option
           http-server-close".



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# File 'lib/rhaproxy/frontend.rb', line 2179

def option_http_use_proxy_header
  @option_http_use_proxy_header
end

#option_httpclose ⇒ Object

option httpclose no option httpclose

Enable or disable passive HTTP connection closing
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

By default, when a client communicates with a server, HAProxy will only
analyze, log, and process the first request of each connection. If "option
httpclose" is set, it will check if a "Connection: close" header is already
set in each direction, and will add one if missing. Each end should react to
this by actively closing the TCP connection after each transfer, thus
resulting in a switch to the HTTP close mode. Any "Connection" header
different from "close" will also be removed.

It seldom happens that some servers incorrectly ignore this header and do not
close the connection eventhough they reply "Connection: close". For this
reason, they are not compatible with older HTTP 1.0 browsers. If this happens
it is possible to use the "option forceclose" which actively closes the
request connection once the server responds. Option "forceclose" also
releases the server connection earlier because it does not have to wait for
the client to acknowledge it.

This option may be set both in a frontend and in a backend. It is enabled if
at least one of the frontend or backend holding a connection has it enabled.
If "option forceclose" is specified too, it has precedence over "httpclose".
If "option http-server-close" is enabled at the same time as "httpclose", it
basically achieves the same result as "option forceclose".

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.

See also : "option forceclose", "option http-server-close" and
           "1.1. The HTTP transaction model".



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# File 'lib/rhaproxy/frontend.rb', line 2217

def option_httpclose
  @option_httpclose
end

#option_httplog ⇒ Object

option httplog [ clf ]

Enable logging of HTTP request, session state and timers
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  clf       if the "clf" argument is added, then the output format will be
            the CLF format instead of HAProxy's default HTTP format. You can
            use this when you need to feed HAProxy's logs through a specific
            log analyser which only support the CLF format and which is not
            extensible.

By default, the log output format is very poor, as it only contains the
source and destination addresses, and the instance name. By specifying
"option httplog", each log line turns into a much richer format including,
but not limited to, the HTTP request, the connection timers, the session
status, the connections numbers, the captured headers and cookies, the
frontend, backend and server name, and of course the source address and
ports.

This option may be set either in the frontend or the backend.

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it. Specifying
only "option httplog" will automatically clear the 'clf' mode if it was set
by default.

See also :  section 8 about logging.



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# File 'lib/rhaproxy/frontend.rb', line 2248

def option_httplog
  @option_httplog
end

#option_ignore_presist ⇒ Object

option ignore-persist { if | unless } <condition>

Declare a condition to ignore persistence
May be used in sections:    defaults | frontend | listen | backend
                                no   |    yes   |   yes  |   yes

By default, when cookie persistence is enabled, every requests containing
the cookie are unconditionally persistent (assuming the target server is up
and running).

The "ignore-persist" statement allows one to declare various ACL-based
conditions which, when met, will cause a request to ignore persistence.
This is sometimes useful to load balance requests for static files, which
oftenly don't require persistence. This can also be used to fully disable
persistence for a specific User-Agent (for example, some web crawler bots).

Combined with "appsession", it can also help reduce HAProxy memory usage, as
the appsession table won't grow if persistence is ignored.

The persistence is ignored when an "if" condition is met, or unless an
"unless" condition is met.

See also : "option force-persist", "cookie", and section 7 about ACL usage.



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# File 'lib/rhaproxy/frontend.rb', line 510

def option_ignore_presist
  @option_ignore_presist
end

#option_independant_streams ⇒ Object

option independant-streams no option independant-streams

Enable or disable independant timeout processing for both directions
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |  yes
Arguments : none

By default, when data is sent over a socket, both the write timeout and the
read timeout for that socket are refreshed, because we consider that there is
activity on that socket, and we have no other means of guessing if we should
receive data or not.

While this default behaviour is desirable for almost all applications, there
exists a situation where it is desirable to disable it, and only refresh the
read timeout if there are incoming data. This happens on sessions with large
timeouts and low amounts of exchanged data such as telnet session. If the
server suddenly disappears, the output data accumulates in the system's
socket buffers, both timeouts are correctly refreshed, and there is no way
to know the server does not receive them, so we don't timeout. However, when
the underlying protocol always echoes sent data, it would be enough by itself
to detect the issue using the read timeout. Note that this problem does not
happen with more verbose protocols because data won't accumulate long in the
socket buffers.

When this option is set on the frontend, it will disable read timeout updates
on data sent to the client. There probably is little use of this case. When
the option is set on the backend, it will disable read timeout updates on
data sent to the server. Doing so will typically break large HTTP posts from
slow lines, so use it with caution.

See also : "timeout client" and "timeout server"



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# File 'lib/rhaproxy/frontend.rb', line 2317

def option_independant_streams
  @option_independant_streams
end

#option_log_separate_errors ⇒ Object

option log-separate-errors no option log-separate-errors

Change log level for non-completely successful connections
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments : none

Sometimes looking for errors in logs is not easy. This option makes haproxy
raise the level of logs containing potentially interesting information such
as errors, timeouts, retries, redispatches, or HTTP status codes 5xx. The
level changes from "info" to "err". This makes it possible to log them
separately to a different file with most syslog daemons. Be careful not to
remove them from the original file, otherwise you would lose ordering which
provides very important information.

Using this option, large sites dealing with several thousand connections per
second may log normal traffic to a rotating buffer and only archive smaller
error logs.

See also : "log", "dontlognull", "dontlog-normal" and section 8 about
           logging.



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# File 'lib/rhaproxy/frontend.rb', line 2342

def option_log_separate_errors
  @option_log_separate_errors
end

#option_logasap ⇒ Object

option logasap no option logasap

Enable or disable early logging of HTTP requests
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments : none

By default, HTTP requests are logged upon termination so that the total
transfer time and the number of bytes appear in the logs. When large objects
are being transferred, it may take a while before the request appears in the
logs. Using "option logasap", the request gets logged as soon as the server
sends the complete headers. The only missing information in the logs will be
the total number of bytes which will indicate everything except the amount
of data transferred, and the total time which will not take the transfer
time into account. In such a situation, it's a good practice to capture the
"Content-Length" response header so that the logs at least indicate how many
bytes are expected to be transferred.

Examples :
    listen http_proxy 0.0.0.0:80
        mode http
        option httplog
        option logasap
        log 192.168.2.200 local3

  >>> Feb  6 12:14:14 localhost \
        haproxy[14389]: 10.0.1.2:33317 [06/Feb/2009:12:14:14.655] http-in \
        static/srv1 9/10/7/14/+30 200 +243 - - ---- 3/1/1/1/0 1/0 \
        "GET /image.iso HTTP/1.0"

See also : "option httplog", "capture response header", and section 8 about
           logging.



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# File 'lib/rhaproxy/frontend.rb', line 2378

def option_logasap
  @option_logasap
end

#option_nolinger ⇒ Object

option nolinger no option nolinger

Enable or disable immediate session resource cleaning after close
May be used in sections:    defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

When clients or servers abort connections in a dirty way (eg: they are
physically disconnected), the session timeouts triggers and the session is
closed. But it will remain in FIN_WAIT1 state for some time in the system,
using some resources and possibly limiting the ability to establish newer
connections.

When this happens, it is possible to activate "option nolinger" which forces
the system to immediately remove any socket's pending data on close. Thus,
the session is instantly purged from the system's tables. This usually has
side effects such as increased number of TCP resets due to old retransmits
getting immediately rejected. Some firewalls may sometimes complain about
this too.

For this reason, it is not recommended to use this option when not absolutely
needed. You know that you need it when you have thousands of FIN_WAIT1
sessions on your system (TIME_WAIT ones do not count).

This option may be used both on frontends and backends, depending on the side
where it is required. Use it on the frontend for clients, and on the backend
for servers.

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.



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# File 'lib/rhaproxy/frontend.rb', line 2412

def option_nolinger
  @option_nolinger
end

#option_originalto ⇒ Object

option originalto [ except <network> ] [ header <name> ]

Enable insertion of the X-Original-To header to requests sent to servers
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  <network> is an optional argument used to disable this option for sources
            matching <network>
  <name>    an optional argument to specify a different "X-Original-To"
            header name.

Since HAProxy can work in transparent mode, every request from a client can
be redirected to the proxy and HAProxy itself can proxy every request to a
complex SQUID environment and the destination host from SO_ORIGINAL_DST will
be lost. This is annoying when you want access rules based on destination ip
addresses. To solve this problem, a new HTTP header "X-Original-To" may be
added by HAProxy to all requests sent to the server. This header contains a
value representing the original destination IP address. Since this must be
configured to always use the last occurrence of this header only. Note that
only the last occurrence of the header must be used, since it is really
possible that the client has already brought one.

The keyword "header" may be used to supply a different header name to replace
the default "X-Original-To". This can be useful where you might already
have a "X-Original-To" header from a different application, and you need
preserve it. Also if your backend server doesn't use the "X-Original-To"
header and requires different one.

Sometimes, a same HAProxy instance may be shared between a direct client
access and a reverse-proxy access (for instance when an SSL reverse-proxy is
used to decrypt HTTPS traffic). It is possible to disable the addition of the
header for a known source address or network by adding the "except" keyword
followed by the network address. In this case, any source IP matching the
network will not cause an addition of this header. Most common uses are with
private networks or 127.0.0.1.

This option may be specified either in the frontend or in the backend. If at
least one of them uses it, the header will be added. Note that the backend's
setting of the header subargument takes precedence over the frontend's if
both are defined.

It is important to note that as long as HAProxy does not support keep-alive
connections, only the first request of a connection will receive the header.
For this reason, it is important to ensure that "option httpclose" is set
when using this option.

Examples :
  # Original Destination address
  frontend www
      mode http
      option originalto except 127.0.0.1

  # Those servers want the IP Address in X-Client-Dst
  backend www
      mode http
      option originalto header X-Client-Dst

See also : "option httpclose"



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# File 'lib/rhaproxy/frontend.rb', line 2473

def option_originalto
  @option_originalto
end

#option_socket_stats ⇒ Object

option socket-stats no option socket-stats

Enable or disable collecting & providing separate statistics for each socket.
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no

Arguments : none



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# File 'lib/rhaproxy/frontend.rb', line 2485

def option_socket_stats
  @option_socket_stats
end

#option_splice_auto ⇒ Object

option splice-auto no option splice-auto

Enable or disable automatic kernel acceleration on sockets in both directions
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

When this option is enabled either on a frontend or on a backend, haproxy
will automatically evaluate the opportunity to use kernel tcp splicing to
forward data between the client and the server, in either direction. Haproxy
uses heuristics to estimate if kernel splicing might improve performance or
not. Both directions are handled independently. Note that the heuristics used
are not much aggressive in order to limit excessive use of splicing. This
option requires splicing to be enabled at compile time, and may be globally
disabled with the global option "nosplice". Since splice uses pipes, using it
requires that there are enough spare pipes.

Important note: kernel-based TCP splicing is a Linux-specific feature which
first appeared in kernel 2.6.25. It offers kernel-based acceleration to
transfer data between sockets without copying these data to user-space, thus
providing noticeable performance gains and CPU cycles savings. Since many
early implementations are buggy, corrupt data and/or are inefficient, this
feature is not enabled by default, and it should be used with extreme care.
While it is not possible to detect the correctness of an implementation,
2.6.29 is the first version offering a properly working implementation. In
case of doubt, splicing may be globally disabled using the global "nosplice"
keyword.

Example :
      option splice-auto

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.

See also : "option splice-request", "option splice-response", and global
           options "nosplice" and "maxpipes"



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# File 'lib/rhaproxy/frontend.rb', line 2525

def option_splice_auto
  @option_splice_auto
end

#option_splice_request ⇒ Object

option splice-request no option splice-request

Enable or disable automatic kernel acceleration on sockets for requests
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

When this option is enabled either on a frontend or on a backend, haproxy
will user kernel tcp splicing whenever possible to forward data going from
the client to the server. It might still use the recv/send scheme if there
are no spare pipes left. This option requires splicing to be enabled at
compile time, and may be globally disabled with the global option "nosplice".
Since splice uses pipes, using it requires that there are enough spare pipes.

Important note: see "option splice-auto" for usage limitations.

Example :
      option splice-request

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.

See also : "option splice-auto", "option splice-response", and global options
           "nosplice" and "maxpipes"



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# File 'lib/rhaproxy/frontend.rb', line 2553

def option_splice_request
  @option_splice_request
end

#option_splice_response ⇒ Object

option splice-response no option splice-response

Enable or disable automatic kernel acceleration on sockets for responses
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

When this option is enabled either on a frontend or on a backend, haproxy
will user kernel tcp splicing whenever possible to forward data going from
the server to the client. It might still use the recv/send scheme if there
are no spare pipes left. This option requires splicing to be enabled at
compile time, and may be globally disabled with the global option "nosplice".
Since splice uses pipes, using it requires that there are enough spare pipes.

Important note: see "option splice-auto" for usage limitations.

Example :
      option splice-response

If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.

See also : "option splice-auto", "option splice-request", and global options
           "nosplice" and "maxpipes"



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# File 'lib/rhaproxy/frontend.rb', line 2581

def option_splice_response
  @option_splice_response
end

#option_tcp_smart_accept ⇒ Object

option tcp-smart-accept no option tcp-smart-accept

Enable or disable the saving of one ACK packet during the accept sequence
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |    no
Arguments : none

When an HTTP connection request comes in, the system acknowledges it on
behalf of HAProxy, then the client immediately sends its request, and the
system acknowledges it too while it is notifying HAProxy about the new
connection. HAProxy then reads the request and responds. This means that we
have one TCP ACK sent by the system for nothing, because the request could
very well be acknowledged by HAProxy when it sends its response.

For this reason, in HTTP mode, HAProxy automatically asks the system to avoid
sending this useless ACK on platforms which support it (currently at least
Linux). It must not cause any problem, because the system will send it anyway
after 40 ms if the response takes more time than expected to come.

During complex network debugging sessions, it may be desirable to disable
this optimization because delayed ACKs can make troubleshooting more complex
when trying to identify where packets are delayed. It is then possible to
fall back to normal behaviour by specifying "no option tcp-smart-accept".

It is also possible to force it for non-HTTP proxies by simply specifying
"option tcp-smart-accept". For instance, it can make sense with some services
such as SMTP where the server speaks first.

It is recommended to avoid forcing this option in a defaults section. In case
of doubt, consider setting it back to automatic values by prepending the
"default" keyword before it, or disabling it using the "no" keyword.

See also : "option tcp-smart-connect"



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# File 'lib/rhaproxy/frontend.rb', line 2618

def option_tcp_smart_accept
  @option_tcp_smart_accept
end

#option_tcpka ⇒ Object

option tcpka

Enable or disable the sending of TCP keepalive packets on both sides
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

When there is a firewall or any session-aware component between a client and
a server, and when the protocol involves very long sessions with long idle
periods (eg: remote desktops), there is a risk that one of the intermediate
components decides to expire a session which has remained idle for too long.

Enabling socket-level TCP keep-alives makes the system regularly send packets
to the other end of the connection, leaving it active. The delay between
keep-alive probes is controlled by the system only and depends both on the
operating system and its tuning parameters.

It is important to understand that keep-alive packets are neither emitted nor
received at the application level. It is only the network stacks which sees
them. For this reason, even if one side of the proxy already uses keep-alives
to maintain its connection alive, those keep-alive packets will not be
forwarded to the other side of the proxy.

Please note that this has nothing to do with HTTP keep-alive.

Using option "tcpka" enables the emission of TCP keep-alive probes on both
the client and server sides of a connection. Note that this is meaningful
only in "defaults" or "listen" sections. If this option is used in a
frontend, only the client side will get keep-alives, and if this option is
used in a backend, only the server side will get keep-alives. For this
reason, it is strongly recommended to explicitly use "option clitcpka" and
"option srvtcpka" when the configuration is split between frontends and
backends.

See also : "option clitcpka", "option srvtcpka"



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# File 'lib/rhaproxy/frontend.rb', line 2656

def option_tcpka
  @option_tcpka
end

#option_tcplog ⇒ Object

option tcplog

Enable advanced logging of TCP connections with session state and timers
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments : none

By default, the log output format is very poor, as it only contains the
source and destination addresses, and the instance name. By specifying
"option tcplog", each log line turns into a much richer format including, but
not limited to, the connection timers, the session status, the connections
numbers, the frontend, backend and server name, and of course the source
address and ports. This option is useful for pure TCP proxies in order to
find which of the client or server disconnects or times out. For normal HTTP
proxies, it's better to use "option httplog" which is even more complete.

This option may be set either in the frontend or the backend.

See also :  "option httplog", and section 8 about logging.



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# File 'lib/rhaproxy/frontend.rb', line 2678

def option_tcplog
  @option_tcplog
end

#persistent_id ⇒ Object

id <value>

Set a persistent ID to a proxy.
May be used in sections :   defaults | frontend | listen | backend
                                no   |    yes   |   yes  |   yes
Arguments : none

Set a persistent ID for the proxy. This ID must be unique and positive.
An unused ID will automatically be assigned if unset. The first assigned
value will be 1. This ID is currently only returned in statistics.



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# File 'lib/rhaproxy/frontend.rb', line 420

def persistent_id
  @persistent_id
end

#rate_limit_sessions ⇒ Object

rate-limit sessions <rate>

Set a limit on the number of new sessions accepted per second on a frontend
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments :
  <rate>    The <rate> parameter is an integer designating the maximum number
            of new sessions per second to accept on the frontend.

When the frontend reaches the specified number of new sessions per second, it
stops accepting new connections until the rate drops below the limit again.
During this time, the pending sessions will be kept in the socket's backlog
(in system buffers) and haproxy will not even be aware that sessions are
pending. When applying very low limit on a highly loaded service, it may make
sense to increase the socket's backlog using the "backlog" keyword.

This feature is particularly efficient at blocking connection-based attacks
or service abuse on fragile servers. Since the session rate is measured every
millisecond, it is extremely accurate. Also, the limit applies immediately,
no delay is needed at all to detect the threshold.

Example : limit the connection rate on SMTP to 10 per second max
      listen smtp
          mode tcp
          bind :25
          rate-limit sessions 10
          server 127.0.0.1:1025

Note : when the maximum rate is reached, the frontend's status appears as
       "FULL" in the statistics, exactly as when it is saturated.

See also : the "backlog" keyword and the "fe_sess_rate" ACL criterion.



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# File 'lib/rhaproxy/frontend.rb', line 2713

def rate_limit_sessions
  @rate_limit_sessions
end

#redirect ⇒ Object

redirect location <to> [code <code>] <option> [(if | unless) <condition>] redirect prefix <to> [code <code>] <option> [(if | unless) <condition>]

Return an HTTP redirection if/unless a condition is matched
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes

If/unless the condition is matched, the HTTP request will lead to a redirect
response. If no condition is specified, the redirect applies unconditionally.

Arguments :
  <to>      With "redirect location", the exact value in <to> is placed into
            the HTTP "Location" header. In case of "redirect prefix", the
            "Location" header is built from the concatenation of <to> and the
            complete URI, including the query string, unless the "drop-query"
            option is specified (see below). As a special case, if <to>
            equals exactly "/" in prefix mode, then nothing is inserted
            before the original URI. It allows one to redirect to the same
            URL.

  <code>    The code is optional. It indicates which type of HTTP redirection
            is desired. Only codes 301, 302 and 303 are supported, and 302 is
            used if no code is specified. 301 means "Moved permanently", and
            a browser may cache the Location. 302 means "Moved permanently"
            and means that the browser should not cache the redirection. 303
            is equivalent to 302 except that the browser will fetch the
            location with a GET method.

  <option>  There are several options which can be specified to adjust the
            expected behaviour of a redirection :

    - "drop-query"
      When this keyword is used in a prefix-based redirection, then the
      location will be set without any possible query-string, which is useful
      for directing users to a non-secure page for instance. It has no effect
      with a location-type redirect.

    - "append-slash"
      This keyword may be used in conjunction with "drop-query" to redirect
      users who use a URL not ending with a '/' to the same one with the '/'.
      It can be useful to ensure that search engines will only see one URL.
      For this, a return code 301 is preferred.

    - "set-cookie NAME[=value]"
      A "Set-Cookie" header will be added with NAME (and optionally "=value")
      to the response. This is sometimes used to indicate that a user has
      been seen, for instance to protect against some types of DoS. No other
      cookie option is added, so the cookie will be a session cookie. Note
      that for a browser, a sole cookie name without an equal sign is
      different from a cookie with an equal sign.

    - "clear-cookie NAME[=]"
      A "Set-Cookie" header will be added with NAME (and optionally "="), but
      with the "Max-Age" attribute set to zero. This will tell the browser to
      delete this cookie. It is useful for instance on logout pages. It is
      important to note that clearing the cookie "NAME" will not remove a
      cookie set with "NAME=value". You have to clear the cookie "NAME=" for
      that, because the browser makes the difference.

Example: move the login URL only to HTTPS.
      acl clear      dst_port  80
      acl secure     dst_port  8080
      acl login_page url_beg   /login
      acl logout     url_beg   /logout
      acl uid_given  url_reg   /login?userid=[^&]+
      acl cookie_set hdr_sub(cookie) SEEN=1

      redirect prefix   https://mysite.com set-cookie SEEN=1 if !cookie_set
      redirect prefix   https://mysite.com           if login_page !secure
      redirect prefix   http://mysite.com drop-query if login_page !uid_given
      redirect location http://mysite.com/           if !login_page secure
      redirect location / clear-cookie USERID=       if logout

Example: send redirects for request for articles without a '/'.
      acl missing_slash path_reg ^/article/[^/]*$
      redirect code 301 prefix / drop-query append-slash if missing_slash

See section 7 about ACL usage.



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# File 'lib/rhaproxy/frontend.rb', line 591

def redirect
  @redirect
end

#reqadd ⇒ Object

reqadd <string> [(if | unless) <cond>]

Add a header at the end of the HTTP request
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <string>  is the complete line to be added. Any space or known delimiter
            must be escaped using a backslash ('\'). Please refer to section
            6 about HTTP header manipulation for more information.

  <cond>    is an optional matching condition built from ACLs. It makes it
            possible to ignore this rule when other conditions are not met.

A new line consisting in <string> followed by a line feed will be added after
the last header of an HTTP request.

Header transformations only apply to traffic which passes through HAProxy,
and not to traffic generated by HAProxy, such as health-checks or error
responses.

Example : add "X-Proto: SSL" to requests coming via port 81
   acl is-ssl  dst_port       81
   reqadd      X-Proto:\ SSL  if is-ssl

See also: "rspadd", section 6 about HTTP header manipulation, and section 7
          about ACLs.



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# File 'lib/rhaproxy/frontend.rb', line 620

def reqadd
  @reqadd
end

#reqallow ⇒ Object

reqallow <search> [(if | unless) <cond>] reqiallow <search> [(if | unless) <cond>] (ignore case)

Definitely allow an HTTP request if a line matches a regular expression
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <search>  is the regular expression applied to HTTP headers and to the
            request line. This is an extended regular expression. Parenthesis
            grouping is supported and no preliminary backslash is required.
            Any space or known delimiter must be escaped using a backslash
            ('\'). The pattern applies to a full line at a time. The
            "reqallow" keyword strictly matches case while "reqiallow"
            ignores case.

  <cond>    is an optional matching condition built from ACLs. It makes it
            possible to ignore this rule when other conditions are not met.

A request containing any line which matches extended regular expression
<search> will mark the request as allowed, even if any later test would
result in a deny. The test applies both to the request line and to request
headers. Keep in mind that URLs in request line are case-sensitive while
header names are not.

It is easier, faster and more powerful to use ACLs to write access policies.
Reqdeny, reqallow and reqpass should be avoided in new designs.

Example :
   # allow www.* but refuse *.local
   reqiallow ^Host:\ www\.
   reqideny  ^Host:\ .*\.local

See also: "reqdeny", "block", section 6 about HTTP header manipulation, and
          section 7 about ACLs.



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# File 'lib/rhaproxy/frontend.rb', line 657

def reqallow
  @reqallow
end

#reqdel ⇒ Object

reqdel <search> [(if | unless) <cond>] reqidel <search> [(if | unless) <cond>] (ignore case)

Delete all headers matching a regular expression in an HTTP request
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <search>  is the regular expression applied to HTTP headers and to the
            request line. This is an extended regular expression. Parenthesis
            grouping is supported and no preliminary backslash is required.
            Any space or known delimiter must be escaped using a backslash
            ('\'). The pattern applies to a full line at a time. The "reqdel"
            keyword strictly matches case while "reqidel" ignores case.

  <cond>    is an optional matching condition built from ACLs. It makes it
            possible to ignore this rule when other conditions are not met.

Any header line matching extended regular expression <search> in the request
will be completely deleted. Most common use of this is to remove unwanted
and/or dangerous headers or cookies from a request before passing it to the
next servers.

Header transformations only apply to traffic which passes through HAProxy,
and not to traffic generated by HAProxy, such as health-checks or error
responses. Keep in mind that header names are not case-sensitive.

Example :
   # remove X-Forwarded-For header and SERVER cookie
   reqidel ^X-Forwarded-For:.*
   reqidel ^Cookie:.*SERVER=

See also: "reqadd", "reqrep", "rspdel", section 6 about HTTP header
          manipulation, and section 7 about ACLs.



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# File 'lib/rhaproxy/frontend.rb', line 694

def reqdel
  @reqdel
end

#reqdeny ⇒ Object

reqdeny <search> [(if | unless) <cond>] reqideny <search> [(if | unless) <cond>] (ignore case)

Deny an HTTP request if a line matches a regular expression
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <search>  is the regular expression applied to HTTP headers and to the
            request line. This is an extended regular expression. Parenthesis
            grouping is supported and no preliminary backslash is required.
            Any space or known delimiter must be escaped using a backslash
            ('\'). The pattern applies to a full line at a time. The
            "reqdeny" keyword strictly matches case while "reqideny" ignores
            case.

  <cond>    is an optional matching condition built from ACLs. It makes it
            possible to ignore this rule when other conditions are not met.

A request containing any line which matches extended regular expression
<search> will mark the request as denied, even if any later test would
result in an allow. The test applies both to the request line and to request
headers. Keep in mind that URLs in request line are case-sensitive while
header names are not.

A denied request will generate an "HTTP 403 forbidden" response once the
complete request has been parsed. This is consistent with what is practiced
using ACLs.

It is easier, faster and more powerful to use ACLs to write access policies.
Reqdeny, reqallow and reqpass should be avoided in new designs.

Example :
   # refuse *.local, then allow www.*
   reqideny  ^Host:\ .*\.local
   reqiallow ^Host:\ www\.

See also: "reqallow", "rspdeny", "block", section 6 about HTTP header
          manipulation, and section 7 about ACLs.



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# File 'lib/rhaproxy/frontend.rb', line 736

def reqdeny
  @reqdeny
end

#reqiallow ⇒ Object

Returns the value of attribute reqiallow.



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# File 'lib/rhaproxy/frontend.rb', line 658

def reqiallow
  @reqiallow
end

#reqidel ⇒ Object

Returns the value of attribute reqidel.



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# File 'lib/rhaproxy/frontend.rb', line 695

def reqidel
  @reqidel
end

#reqideny ⇒ Object

Returns the value of attribute reqideny.



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# File 'lib/rhaproxy/frontend.rb', line 737

def reqideny
  @reqideny
end

#reqipass ⇒ Object

Returns the value of attribute reqipass.



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# File 'lib/rhaproxy/frontend.rb', line 775

def reqipass
  @reqipass
end

#reqirep ⇒ Object

Returns the value of attribute reqirep.



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# File 'lib/rhaproxy/frontend.rb', line 820

def reqirep
  @reqirep
end

#reqisetbe ⇒ Object

Returns the value of attribute reqisetbe.



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# File 'lib/rhaproxy/frontend.rb', line 2859

def reqisetbe
  @reqisetbe
end

#reqitarpit ⇒ Object

Returns the value of attribute reqitarpit.



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# File 'lib/rhaproxy/frontend.rb', line 868

def reqitarpit
  @reqitarpit
end

#reqpass ⇒ Object

reqpass <search> [(if | unless) <cond>] reqipass <search> [(if | unless) <cond>] (ignore case)

Ignore any HTTP request line matching a regular expression in next rules
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <search>  is the regular expression applied to HTTP headers and to the
            request line. This is an extended regular expression. Parenthesis
            grouping is supported and no preliminary backslash is required.
            Any space or known delimiter must be escaped using a backslash
            ('\'). The pattern applies to a full line at a time. The
            "reqpass" keyword strictly matches case while "reqipass" ignores
            case.

  <cond>    is an optional matching condition built from ACLs. It makes it
            possible to ignore this rule when other conditions are not met.

A request containing any line which matches extended regular expression
<search> will skip next rules, without assigning any deny or allow verdict.
The test applies both to the request line and to request headers. Keep in
mind that URLs in request line are case-sensitive while header names are not.

It is easier, faster and more powerful to use ACLs to write access policies.
Reqdeny, reqallow and reqpass should be avoided in new designs.

Example :
   # refuse *.local, then allow www.*, but ignore "www.private.local"
   reqipass  ^Host:\ www.private\.local
   reqideny  ^Host:\ .*\.local
   reqiallow ^Host:\ www\.

See also: "reqallow", "reqdeny", "block", section 6 about HTTP header
          manipulation, and section 7 about ACLs.



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# File 'lib/rhaproxy/frontend.rb', line 774

def reqpass
  @reqpass
end

#reqrep ⇒ Object

reqrep <search> <string> [(if | unless) <cond>] reqirep <search> <string> [(if | unless) <cond>] (ignore case)

Replace a regular expression with a string in an HTTP request line
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <search>  is the regular expression applied to HTTP headers and to the
            request line. This is an extended regular expression. Parenthesis
            grouping is supported and no preliminary backslash is required.
            Any space or known delimiter must be escaped using a backslash
            ('\'). The pattern applies to a full line at a time. The "reqrep"
            keyword strictly matches case while "reqirep" ignores case.

  <string>  is the complete line to be added. Any space or known delimiter
            must be escaped using a backslash ('\'). References to matched
            pattern groups are possible using the common \N form, with N
            being a single digit between 0 and 9. Please refer to section
            6 about HTTP header manipulation for more information.

  <cond>    is an optional matching condition built from ACLs. It makes it
            possible to ignore this rule when other conditions are not met.

Any line matching extended regular expression <search> in the request (both
the request line and header lines) will be completely replaced with <string>.
Most common use of this is to rewrite URLs or domain names in "Host" headers.

Header transformations only apply to traffic which passes through HAProxy,
and not to traffic generated by HAProxy, such as health-checks or error
responses. Note that for increased readability, it is suggested to add enough
spaces between the request and the response. Keep in mind that URLs in
request line are case-sensitive while header names are not.

Example :
   # replace "/static/" with "/" at the beginning of any request path.
   reqrep ^([^\ ]*)\ /static/(.*)     \1\ /\2
   # replace "www.mydomain.com" with "www" in the host name.
   reqirep ^Host:\ www.mydomain.com   Host:\ www

See also: "reqadd", "reqdel", "rsprep", section 6 about HTTP header
          manipulation, and section 7 about ACLs.



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# File 'lib/rhaproxy/frontend.rb', line 819

def reqrep
  @reqrep
end

#reqsetbe ⇒ Object

Returns the value of attribute reqsetbe.



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# File 'lib/rhaproxy/frontend.rb', line 2860

def reqsetbe
  @reqsetbe
end

#reqtarpit ⇒ Object

reqtarpit <search> [(if | unless) <cond>] reqitarpit <search> [(if | unless) <cond>] (ignore case)

Tarpit an HTTP request containing a line matching a regular expression
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <search>  is the regular expression applied to HTTP headers and to the
            request line. This is an extended regular expression. Parenthesis
            grouping is supported and no preliminary backslash is required.
            Any space or known delimiter must be escaped using a backslash
            ('\'). The pattern applies to a full line at a time. The
            "reqtarpit" keyword strictly matches case while "reqitarpit"
            ignores case.

  <cond>    is an optional matching condition built from ACLs. It makes it
            possible to ignore this rule when other conditions are not met.

A request containing any line which matches extended regular expression
<search> will be tarpitted, which means that it will connect to nowhere, will
be kept open for a pre-defined time, then will return an HTTP error 500 so
that the attacker does not suspect it has been tarpitted. The status 500 will
be reported in the logs, but the completion flags will indicate "PT". The
delay is defined by "timeout tarpit", or "timeout connect" if the former is
not set.

The goal of the tarpit is to slow down robots attacking servers with
identifiable requests. Many robots limit their outgoing number of connections
and stay connected waiting for a reply which can take several minutes to
come. Depending on the environment and attack, it may be particularly
efficient at reducing the load on the network and firewalls.

Examples :
   # ignore user-agents reporting any flavour of "Mozilla" or "MSIE", but
   # block all others.
   reqipass   ^User-Agent:\.*(Mozilla|MSIE)
   reqitarpit ^User-Agent:

   # block bad guys
   acl badguys src 10.1.0.3 172.16.13.20/28
   reqitarpit . if badguys

See also: "reqallow", "reqdeny", "reqpass", section 6 about HTTP header
          manipulation, and section 7 about ACLs.



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# File 'lib/rhaproxy/frontend.rb', line 867

def reqtarpit
  @reqtarpit
end

#rspadd ⇒ Object

rspadd <string> [(if | unless) <cond>]

Add a header at the end of the HTTP response
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <string>  is the complete line to be added. Any space or known delimiter
            must be escaped using a backslash ('\'). Please refer to section
            6 about HTTP header manipulation for more information.

  <cond>    is an optional matching condition built from ACLs. It makes it
            possible to ignore this rule when other conditions are not met.

A new line consisting in <string> followed by a line feed will be added after
the last header of an HTTP response.

Header transformations only apply to traffic which passes through HAProxy,
and not to traffic generated by HAProxy, such as health-checks or error
responses.

See also: "reqadd", section 6 about HTTP header manipulation, and section 7
          about ACLs.



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# File 'lib/rhaproxy/frontend.rb', line 893

def rspadd
  @rspadd
end

#rspdel ⇒ Object

rspdel <search> [(if | unless) <cond>] rspidel <search> [(if | unless) <cond>] (ignore case)

Delete all headers matching a regular expression in an HTTP response
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <search>  is the regular expression applied to HTTP headers and to the
            response line. This is an extended regular expression, so
            parenthesis grouping is supported and no preliminary backslash
            is required. Any space or known delimiter must be escaped using
            a backslash ('\'). The pattern applies to a full line at a time.
            The "rspdel" keyword strictly matches case while "rspidel"
            ignores case.

  <cond>    is an optional matching condition built from ACLs. It makes it
            possible to ignore this rule when other conditions are not met.

Any header line matching extended regular expression <search> in the response
will be completely deleted. Most common use of this is to remove unwanted
and/or sensible headers or cookies from a response before passing it to the
client.

Header transformations only apply to traffic which passes through HAProxy,
and not to traffic generated by HAProxy, such as health-checks or error
responses. Keep in mind that header names are not case-sensitive.

Example :
   # remove the Server header from responses
   reqidel ^Server:.*

See also: "rspadd", "rsprep", "reqdel", section 6 about HTTP header
          manipulation, and section 7 about ACLs.



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# File 'lib/rhaproxy/frontend.rb', line 929

def rspdel
  @rspdel
end

#rspdeny ⇒ Object

rspdeny <search> [(if | unless) <cond>] rspideny <search> [(if | unless) <cond>] (ignore case)

Block an HTTP response if a line matches a regular expression
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <search>  is the regular expression applied to HTTP headers and to the
            response line. This is an extended regular expression, so
            parenthesis grouping is supported and no preliminary backslash
            is required. Any space or known delimiter must be escaped using
            a backslash ('\'). The pattern applies to a full line at a time.
            The "rspdeny" keyword strictly matches case while "rspideny"
            ignores case.

  <cond>    is an optional matching condition built from ACLs. It makes it
            possible to ignore this rule when other conditions are not met.

A response containing any line which matches extended regular expression
<search> will mark the request as denied. The test applies both to the
response line and to response headers. Keep in mind that header names are not
case-sensitive.

Main use of this keyword is to prevent sensitive information leak and to
block the response before it reaches the client. If a response is denied, it
will be replaced with an HTTP 502 error so that the client never retrieves
any sensitive data.

It is easier, faster and more powerful to use ACLs to write access policies.
Rspdeny should be avoided in new designs.

Example :
   # Ensure that no content type matching ms-word will leak
   rspideny  ^Content-type:\.*/ms-word

See also: "reqdeny", "acl", "block", section 6 about HTTP header manipulation
          and section 7 about ACLs.



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# File 'lib/rhaproxy/frontend.rb', line 970

def rspdeny
  @rspdeny
end

#rspidel ⇒ Object

Returns the value of attribute rspidel.



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# File 'lib/rhaproxy/frontend.rb', line 930

def rspidel
  @rspidel
end

#rspideny ⇒ Object

Returns the value of attribute rspideny.



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# File 'lib/rhaproxy/frontend.rb', line 971

def rspideny
  @rspideny
end

#rspirep ⇒ Object

Returns the value of attribute rspirep.



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# File 'lib/rhaproxy/frontend.rb', line 1015

def rspirep
  @rspirep
end

#rsprep ⇒ Object

rsprep <search> <string> [(if | unless) <cond>] rspirep <search> <string> [(if | unless) <cond>] (ignore case)

Replace a regular expression with a string in an HTTP response line
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <search>  is the regular expression applied to HTTP headers and to the
            response line. This is an extended regular expression, so
            parenthesis grouping is supported and no preliminary backslash
            is required. Any space or known delimiter must be escaped using
            a backslash ('\'). The pattern applies to a full line at a time.
            The "rsprep" keyword strictly matches case while "rspirep"
            ignores case.

  <string>  is the complete line to be added. Any space or known delimiter
            must be escaped using a backslash ('\'). References to matched
            pattern groups are possible using the common \N form, with N
            being a single digit between 0 and 9. Please refer to section
            6 about HTTP header manipulation for more information.

  <cond>    is an optional matching condition built from ACLs. It makes it
            possible to ignore this rule when other conditions are not met.

Any line matching extended regular expression <search> in the response (both
the response line and header lines) will be completely replaced with
<string>. Most common use of this is to rewrite Location headers.

Header transformations only apply to traffic which passes through HAProxy,
and not to traffic generated by HAProxy, such as health-checks or error
responses. Note that for increased readability, it is suggested to add enough
spaces between the request and the response. Keep in mind that header names
are not case-sensitive.

Example :
   # replace "Location: 127.0.0.1:8080" with "Location: www.mydomain.com"
   rspirep ^Location:\ 127.0.0.1:8080    Location:\ www.mydomain.com

See also: "rspadd", "rspdel", "reqrep", section 6 about HTTP header
          manipulation, and section 7 about ACLs.



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# File 'lib/rhaproxy/frontend.rb', line 1014

def rsprep
  @rsprep
end

#tcp_request_connection ⇒ Object

tcp-request connection <action> [(if | unless) <condition>]

Perform an action on an incoming connection depending on a layer 4 condition
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   no
Arguments :
  <action>    defines the action to perform if the condition applies. Valid
              actions include : "accept", "reject", "track-sc1", "track-sc2".
              See below for more details.

  <condition> is a standard layer4-only ACL-based condition (see section 7).

Immediately after acceptance of a new incoming connection, it is possible to
evaluate some conditions to decide whether this connection must be accepted
or dropped or have its counters tracked. Those conditions cannot make use of
any data contents because the connection has not been read from yet, and the
buffers are not yet allocated. This is used to selectively and very quickly
accept or drop connections from various sources with a very low overhead. If
some contents need to be inspected in order to take the decision, the
"tcp-request content" statements must be used instead.

The "tcp-request connection" rules are evaluated in their exact declaration
order. If no rule matches or if there is no rule, the default action is to
accept the incoming connection. There is no specific limit to the number of
rules which may be inserted.

Three types of actions are supported :
  - accept :
      accepts the connection if the condition is true (when used with "if")
      or false (when used with "unless"). The first such rule executed ends
      the rules evaluation.

  - reject :
      rejects the connection if the condition is true (when used with "if")
      or false (when used with "unless"). The first such rule executed ends
      the rules evaluation. Rejected connections do not even become a
      session, which is why they are accounted separately for in the stats,
      as "denied connections". They are not considered for the session
      rate-limit and are not logged either. The reason is that these rules
      should only be used to filter extremely high connection rates such as
      the ones encountered during a massive DDoS attack. Under these extreme
      conditions, the simple action of logging each event would make the
      system collapse and would considerably lower the filtering capacity. If
      logging is absolutely desired, then "tcp-request content" rules should
      be used instead.

  - { track-sc1 | track-sc2 } <key> [table <table>] :
      enables tracking of sticky counters from current connection. These
      rules do not stop evaluation and do not change default action. Two sets
      of counters may be simultaneously tracked by the same connection. The
      first "track-sc1" rule executed enables tracking of the counters of the
      specified table as the first set. The first "track-sc2" rule executed
      enables tracking of the counters of the specified table as the second
      set. It is a recommended practice to use the first set of counters for
      the per-frontend counters and the second set for the per-backend ones.

      These actions take one or two arguments :
        <key>   is mandatory, and defines the criterion the tracking key will
                be derived from. At the moment, only "src" is supported. With
                it, the key will be the connection's source IPv4 address.

       <table>  is an optional table to be used instead of the default one,
                which is the stick-table declared in the current proxy. All
                the counters for the matches and updates for the key will
                then be performed in that table until the session ends.

      Once a "track-sc*" rule is executed, the key is looked up in the table
      and if it is not found, an entry is allocated for it. Then a pointer to
      that entry is kept during all the session's life, and this entry's
      counters are updated as often as possible, every time the session's
      counters are updated, and also systematically when the session ends.
      If the entry tracks concurrent connection counters, one connection is
      counted for as long as the entry is tracked, and the entry will not
      expire during that time. Tracking counters also provides a performance
      advantage over just checking the keys, because only one table lookup is
      performed for all ACL checks that make use of it.

Note that the "if/unless" condition is optional. If no condition is set on
the action, it is simply performed unconditionally. That can be useful for
"track-sc*" actions as well as for changing the default action to a reject.

Example: accept all connections from white-listed hosts, reject too fast
         connection without counting them, and track accepted connections.
         This results in connection rate being capped from abusive sources.

      tcp-request connection accept if { src -f /etc/haproxy/whitelist.lst }
      tcp-request connection reject if { src_conn_rate gt 10 }
      tcp-request connection track-sc1 src

Example: accept all connections from white-listed hosts, count all other
         connections and reject too fast ones. This results in abusive ones
         being blocked as long as they don't slow down.

      tcp-request connection accept if { src -f /etc/haproxy/whitelist.lst }
      tcp-request connection track-sc1 src
      tcp-request connection reject if { sc1_conn_rate gt 10 }

See section 7 about ACL usage.

See also : "tcp-request content", "stick-table"



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# File 'lib/rhaproxy/frontend.rb', line 1118

def tcp_request_connection
  @tcp_request_connection
end

#tcp_request_content ⇒ Object

tcp-request content <action> [(if | unless) <condition>]

Perform an action on a new session depending on a layer 4-7 condition
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <action>    defines the action to perform if the condition applies. Valid
              actions include : "accept", "reject", "track-sc1", "track-sc2".
              See "tcp-request connection" above for their signification.

  <condition> is a standard layer 4-7 ACL-based condition (see section 7).

A request's contents can be analysed at an early stage of request processing
called "TCP content inspection". During this stage, ACL-based rules are
evaluated every time the request contents are updated, until either an
"accept" or a "reject" rule matches, or the TCP request inspection delay
expires with no matching rule.

The first difference between these rules and "tcp-request connection" rules
is that "tcp-request content" rules can make use of contents to take a
decision. Most often, these decisions will consider a protocol recognition or
validity. The second difference is that content-based rules can be used in
both frontends and backends. In frontends, they will be evaluated upon new
connections. In backends, they will be evaluated once a session is assigned
a backend. This means that a single frontend connection may be evaluated
several times by one or multiple backends when a session gets reassigned
(for instance after a client-side HTTP keep-alive request).

Content-based rules are evaluated in their exact declaration order. If no
rule matches or if there is no rule, the default action is to accept the
contents. There is no specific limit to the number of rules which may be
inserted.

Three types of actions are supported :
  - accept :
  - reject :
  - { track-sc1 | track-sc2 } <key> [table <table>]

They have the same meaning as their counter-parts in "tcp-request connection"
so please refer to that section for a complete description.

Also, it is worth noting that if sticky counters are tracked from a rule
defined in a backend, this tracking will automatically end when the session
releases the backend. That allows per-backend counter tracking even in case
of HTTP keep-alive requests when the backend changes. While there is nothing
mandatory about it, it is recommended to use the track-sc1 pointer to track
per-frontend counters and track-sc2 to track per-backend counters.

Note that the "if/unless" condition is optional. If no condition is set on
the action, it is simply performed unconditionally. That can be useful for
"track-sc*" actions as well as for changing the default action to a reject.

It is perfectly possible to match layer 7 contents with "tcp-request content"
rules, but then it is important to ensure that a full request has been
buffered, otherwise no contents will match. In order to achieve this, the
best solution involves detecting the HTTP protocol during the inspection
period.

Example:
      # Accept HTTP requests containing a Host header saying "example.com"
      # and reject everything else.
      acl is_host_com hdr(Host) -i example.com
      tcp-request inspect-delay 30s
      tcp-request content accept if HTTP is_host_com
      tcp-request content reject

Example:
      # reject SMTP connection if client speaks first
      tcp-request inspect-delay 30s
      acl content_present req_len gt 0
      tcp-request content reject if content_present

      # Forward HTTPS connection only if client speaks
      tcp-request inspect-delay 30s
      acl content_present req_len gt 0
      tcp-request content accept if content_present
      tcp-request content reject

Example: track per-frontend and per-backend counters, block abusers at the
         frontend when the backend detects abuse.

      frontend http
          # Use General Purpose Couter 0 in SC1 as a global abuse counter
          # protecting all our sites
          stick-table type ip size 1m expire 5m store gpc0
          tcp-request connection track-sc1 src
          tcp-request connection reject if { sc1_get_gpc0 gt 0 }
          ...
          use_backend http_dynamic if { path_end .php }

      backend http_dynamic
          # if a source makes too fast requests to this dynamic site (tracked
          # by SC2), block it globally in the frontend.
          stick-table type ip size 1m expire 5m store http_req_rate(10s)
          acl click_too_fast sc2_http_req_rate gt 10
          acl mark_as_abuser sc1_inc_gpc0
          tcp-request content track-sc2 src
          tcp-request content reject if click_too_fast mark_as_abuser

See section 7 about ACL usage.

See also : "tcp-request connection", "tcp-request inspect-delay"



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# File 'lib/rhaproxy/frontend.rb', line 1223

def tcp_request_content
  @tcp_request_content
end

#tcp_request_inspect_delay ⇒ Object

tcp-request inspect-delay <timeout>

Set the maximum allowed time to wait for data during content inspection
May be used in sections :   defaults | frontend | listen | backend
                               no    |    yes   |   yes  |   yes
Arguments :
  <timeout> is the timeout value specified in milliseconds by default, but
            can be in any other unit if the number is suffixed by the unit,
            as explained at the top of this document.

People using haproxy primarily as a TCP relay are often worried about the
risk of passing any type of protocol to a server without any analysis. In
order to be able to analyze the request contents, we must first withhold
the data then analyze them. This statement simply enables withholding of
data for at most the specified amount of time.

TCP content inspection applies very early when a connection reaches a
frontend, then very early when the connection is forwarded to a backend. This
means that a connection may experience a first delay in the frontend and a
second delay in the backend if both have tcp-request rules.

Note that when performing content inspection, haproxy will evaluate the whole
rules for every new chunk which gets in, taking into account the fact that
those data are partial. If no rule matches before the aforementioned delay,
a last check is performed upon expiration, this time considering that the
contents are definitive. If no delay is set, haproxy will not wait at all
and will immediately apply a verdict based on the available information.
Obviously this is unlikely to be very useful and might even be racy, so such
setups are not recommended.

As soon as a rule matches, the request is released and continues as usual. If
the timeout is reached and no rule matches, the default policy will be to let
it pass through unaffected.

For most protocols, it is enough to set it to a few seconds, as most clients
send the full request immediately upon connection. Add 3 or more seconds to
cover TCP retransmits but that's all. For some protocols, it may make sense
to use large values, for instance to ensure that the client never talks
before the server (eg: SMTP), or to wait for a client to talk before passing
data to the server (eg: SSL). Note that the client timeout must cover at
least the inspection delay, otherwise it will expire first. If the client
closes the connection or if the buffer is full, the delay immediately expires
since the contents will not be able to change anymore.

See also : "tcp-request content accept", "tcp-request content reject",
           "timeout client".



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# File 'lib/rhaproxy/frontend.rb', line 1272

def tcp_request_inspect_delay
  @tcp_request_inspect_delay
end

#timeout_client ⇒ Object

timeout client <timeout> timeout clitimeout <timeout> (deprecated)

Set the maximum inactivity time on the client side.
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   no
Arguments :
  <timeout> is the timeout value specified in milliseconds by default, but
            can be in any other unit if the number is suffixed by the unit,
            as explained at the top of this document.

The inactivity timeout applies when the client is expected to acknowledge or
send data. In HTTP mode, this timeout is particularly important to consider
during the first phase, when the client sends the request, and during the
response while it is reading data sent by the server. The value is specified
in milliseconds by default, but can be in any other unit if the number is
suffixed by the unit, as specified at the top of this document. In TCP mode
(and to a lesser extent, in HTTP mode), it is highly recommended that the
client timeout remains equal to the server timeout in order to avoid complex
situations to debug. It is a good practice to cover one or several TCP packet
losses by specifying timeouts that are slightly above multiples of 3 seconds
(eg: 4 or 5 seconds).

This parameter is specific to frontends, but can be specified once for all in
"defaults" sections. This is in fact one of the easiest solutions not to
forget about it. An unspecified timeout results in an infinite timeout, which
is not recommended. Such a usage is accepted and works but reports a warning
during startup because it may results in accumulation of expired sessions in
the system if the system's timeouts are not configured either.

This parameter replaces the old, deprecated "clitimeout". It is recommended
to use it to write new configurations. The form "timeout clitimeout" is
provided only by backwards compatibility but its use is strongly discouraged.

See also : "clitimeout", "timeout server".



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# File 'lib/rhaproxy/frontend.rb', line 2751

def timeout_client
  @timeout_client
end

#timeout_http_keep_alive ⇒ Object

timeout http-keep-alive <timeout>

Set the maximum allowed time to wait for a new HTTP request to appear
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  <timeout> is the timeout value specified in milliseconds by default, but
            can be in any other unit if the number is suffixed by the unit,
            as explained at the top of this document.

By default, the time to wait for a new request in case of keep-alive is set
by "timeout http-request". However this is not always convenient because some
people want very short keep-alive timeouts in order to release connections
faster, and others prefer to have larger ones but still have short timeouts
once the request has started to present itself.

The "http-keep-alive" timeout covers these needs. It will define how long to
wait for a new HTTP request to start coming after a response was sent. Once
the first byte of request has been seen, the "http-request" timeout is used
to wait for the complete request to come. Note that empty lines prior to a
new request do not refresh the timeout and are not counted as a new request.

There is also another difference between the two timeouts : when a connection
expires during timeout http-keep-alive, no error is returned, the connection
just closes. If the connection expires in "http-request" while waiting for a
connection to complete, a HTTP 408 error is returned.

In general it is optimal to set this value to a few tens to hundreds of
milliseconds, to allow users to fetch all objects of a page at once but
without waiting for further clicks. Also, if set to a very small value (eg:
1 millisecond) it will probably only accept pipelined requests but not the
non-pipelined ones. It may be a nice trade-off for very large sites running
with tens to hundreds of thousands of clients.

If this parameter is not set, the "http-request" timeout applies, and if both
are not set, "timeout client" still applies at the lower level. It should be
set in the frontend to take effect, unless the frontend is in TCP mode, in
which case the HTTP backend's timeout will be used.

See also : "timeout http-request", "timeout client".



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# File 'lib/rhaproxy/frontend.rb', line 2794

def timeout_http_keep_alive
  @timeout_http_keep_alive
end

#timeout_http_request ⇒ Object

timeout http-request <timeout>

Set the maximum allowed time to wait for a complete HTTP request
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  <timeout> is the timeout value specified in milliseconds by default, but
            can be in any other unit if the number is suffixed by the unit,
            as explained at the top of this document.

In order to offer DoS protection, it may be required to lower the maximum
accepted time to receive a complete HTTP request without affecting the client
timeout. This helps protecting against established connections on which
nothing is sent. The client timeout cannot offer a good protection against
this abuse because it is an inactivity timeout, which means that if the
attacker sends one character every now and then, the timeout will not
trigger. With the HTTP request timeout, no matter what speed the client
types, the request will be aborted if it does not complete in time.

Note that this timeout only applies to the header part of the request, and
not to any data. As soon as the empty line is received, this timeout is not
used anymore. It is used again on keep-alive connections to wait for a second
request if "timeout http-keep-alive" is not set.

Generally it is enough to set it to a few seconds, as most clients send the
full request immediately upon connection. Add 3 or more seconds to cover TCP
retransmits but that's all. Setting it to very low values (eg: 50 ms) will
generally work on local networks as long as there are no packet losses. This
will prevent people from sending bare HTTP requests using telnet.

If this parameter is not set, the client timeout still applies between each
chunk of the incoming request. It should be set in the frontend to take
effect, unless the frontend is in TCP mode, in which case the HTTP backend's
timeout will be used.

See also : "timeout http-keep-alive", "timeout client".



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# File 'lib/rhaproxy/frontend.rb', line 2833

def timeout_http_request
  @timeout_http_request
end

#timeout_tarpit ⇒ Object

timeout tarpit <timeout>

Set the duration for which tarpitted connections will be maintained
May be used in sections :   defaults | frontend | listen | backend
                               yes   |    yes   |   yes  |   yes
Arguments :
  <timeout> is the tarpit duration specified in milliseconds by default, but
            can be in any other unit if the number is suffixed by the unit,
            as explained at the top of this document.

When a connection is tarpitted using "reqtarpit", it is maintained open with
no activity for a certain amount of time, then closed. "timeout tarpit"
defines how long it will be maintained open.

The value is specified in milliseconds by default, but can be in any other
unit if the number is suffixed by the unit, as specified at the top of this
document. If unspecified, the same value as the backend's connection timeout
("timeout connect") is used, for backwards compatibility with older versions
with no "timeout tarpit" parameter.

See also : "timeout connect", "contimeout".



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# File 'lib/rhaproxy/frontend.rb', line 2857

def timeout_tarpit
  @timeout_tarpit
end

#use_backend ⇒ Object

use_backend <backend> if <condition> use_backend <backend> unless <condition>

Switch to a specific backend if/unless an ACL-based condition is matched.
May be used in sections :   defaults | frontend | listen | backend
                                no   |    yes   |   yes  |   no
Arguments :
  <backend>   is the name of a valid backend or "listen" section.

  <condition> is a condition composed of ACLs, as described in section 7.

When doing content-switching, connections arrive on a frontend and are then
dispatched to various backends depending on a number of conditions. The
relation between the conditions and the backends is described with the
"use_backend" keyword. While it is normally used with HTTP processing, it can
also be used in pure TCP, either without content using stateless ACLs (eg:
source address validation) or combined with a "tcp-request" rule to wait for
some payload.

There may be as many "use_backend" rules as desired. All of these rules are
evaluated in their declaration order, and the first one which matches will
assign the backend.

In the first form, the backend will be used if the condition is met. In the
second form, the backend will be used if the condition is not met. If no
condition is valid, the backend defined with "default_backend" will be used.
If no default backend is defined, either the servers in the same section are
used (in case of a "listen" section) or, in case of a frontend, no server is
used and a 503 service unavailable response is returned.

Note that it is possible to switch from a TCP frontend to an HTTP backend. In
this case, either the frontend has already checked that the protocol is HTTP,
and backend processing will immediately follow, or the backend will wait for
a complete HTTP request to get in. This feature is useful when a frontend
must decode several protocols on a unique port, one of them being HTTP.

See also: "default_backend", "tcp-request", and section 7 about ACLs.



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# File 'lib/rhaproxy/frontend.rb', line 1312

def use_backend
  @use_backend
end

Instance Method Details

#config ⇒ Object

Compile the HAproxy frontend configuration



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# File 'lib/rhaproxy/frontend.rb', line 2877

def config

  if @name

    conf = option_string()

    return conf

  else

    puts "frontend name not defined"

    return false

  end

end