Class: Synapse::Haproxy

Inherits:
Object
  • Object
show all
Includes:
Logging
Defined in:
lib/synapse/haproxy.rb

Constant Summary collapse

@@section_fields =

these come from the documentation for haproxy 1.5 haproxy.1wt.eu/download/1.5/doc/configuration.txt

{
  "backend" => [
    "acl",
    "appsession",
    "balance",
    "bind-process",
    "block",
    "compression",
    "contimeout",
    "cookie",
    "default-server",
    "description",
    "disabled",
    "dispatch",
    "enabled",
    "errorfile",
    "errorloc",
    "errorloc302",
    "errorloc303",
    "force-persist",
    "fullconn",
    "grace",
    "hash-type",
    "http-check disable-on-404",
    "http-check expect",
    "http-check send-state",
    "http-request",
    "http-response",
    "id",
    "ignore-persist",
    "log",
    "mode",
    "option abortonclose",
    "option accept-invalid-http-response",
    "option allbackups",
    "option checkcache",
    "option forceclose",
    "option forwardfor",
    "option http-no-delay",
    "option http-pretend-keepalive",
    "option http-server-close",
    "option httpchk",
    "option httpclose",
    "option httplog",
    "option http_proxy",
    "option independent-streams",
    "option lb-agent-chk",
    "option ldap-check",
    "option log-health-checks",
    "option mysql-check",
    "option pgsql-check",
    "option nolinger",
    "option originalto",
    "option persist",
    "option redispatch",
    "option redis-check",
    "option smtpchk",
    "option splice-auto",
    "option splice-request",
    "option splice-response",
    "option srvtcpka",
    "option ssl-hello-chk",
    "option tcp-smart-connect",
    "option tcpka",
    "option tcplog",
    "option transparent",
    "persist rdp-cookie",
    "redirect",
    "redisp",
    "redispatch",
    "reqadd",
    "reqallow",
    "reqdel",
    "reqdeny",
    "reqiallow",
    "reqidel",
    "reqideny",
    "reqipass",
    "reqirep",
    "reqisetbe",
    "reqitarpit",
    "reqpass",
    "reqrep",
    "reqsetbe",
    "reqtarpit",
    "retries",
    "rspadd",
    "rspdel",
    "rspdeny",
    "rspidel",
    "rspideny",
    "rspirep",
    "rsprep",
    "server",
    "source",
    "srvtimeout",
    "stats admin",
    "stats auth",
    "stats enable",
    "stats hide-version",
    "stats http-request",
    "stats realm",
    "stats refresh",
    "stats scope",
    "stats show-desc",
    "stats show-legends",
    "stats show-node",
    "stats uri",
    "stick match",
    "stick on",
    "stick store-request",
    "stick store-response",
    "stick-table",
    "tcp-request content",
    "tcp-request inspect-delay",
    "tcp-response content",
    "tcp-response inspect-delay",
    "timeout check",
    "timeout connect",
    "timeout contimeout",
    "timeout http-keep-alive",
    "timeout http-request",
    "timeout queue",
    "timeout server",
    "timeout srvtimeout",
    "timeout tarpit",
    "timeout tunnel",
    "transparent",
    "use-server"
  ],
  "defaults" => [
    "backlog",
    "balance",
    "bind-process",
    "clitimeout",
    "compression",
    "contimeout",
    "cookie",
    "default-server",
    "default_backend",
    "disabled",
    "enabled",
    "errorfile",
    "errorloc",
    "errorloc302",
    "errorloc303",
    "fullconn",
    "grace",
    "hash-type",
    "http-check disable-on-404",
    "http-check send-state",
    "log",
    "maxconn",
    "mode",
    "monitor-net",
    "monitor-uri",
    "option abortonclose",
    "option accept-invalid-http-request",
    "option accept-invalid-http-response",
    "option allbackups",
    "option checkcache",
    "option clitcpka",
    "option contstats",
    "option dontlog-normal",
    "option dontlognull",
    "option forceclose",
    "option forwardfor",
    "option http-no-delay",
    "option http-pretend-keepalive",
    "option http-server-close",
    "option http-use-proxy-header",
    "option httpchk",
    "option httpclose",
    "option httplog",
    "option http_proxy",
    "option independent-streams",
    "option lb-agent-chk",
    "option ldap-check",
    "option log-health-checks",
    "option log-separate-errors",
    "option logasap",
    "option mysql-check",
    "option pgsql-check",
    "option nolinger",
    "option originalto",
    "option persist",
    "option redispatch",
    "option redis-check",
    "option smtpchk",
    "option socket-stats",
    "option splice-auto",
    "option splice-request",
    "option splice-response",
    "option srvtcpka",
    "option ssl-hello-chk",
    "option tcp-smart-accept",
    "option tcp-smart-connect",
    "option tcpka",
    "option tcplog",
    "option transparent",
    "persist rdp-cookie",
    "rate-limit sessions",
    "redisp",
    "redispatch",
    "retries",
    "source",
    "srvtimeout",
    "stats auth",
    "stats enable",
    "stats hide-version",
    "stats realm",
    "stats refresh",
    "stats scope",
    "stats show-desc",
    "stats show-legends",
    "stats show-node",
    "stats uri",
    "timeout check",
    "timeout client",
    "timeout clitimeout",
    "timeout connect",
    "timeout contimeout",
    "timeout http-keep-alive",
    "timeout http-request",
    "timeout queue",
    "timeout server",
    "timeout srvtimeout",
    "timeout tarpit",
    "timeout tunnel",
    "transparent",
    "unique-id-format",
    "unique-id-header"
  ],
  "frontend" => [
    "acl",
    "backlog",
    "bind",
    "bind-process",
    "block",
    "capture cookie",
    "capture request header",
    "capture response header",
    "clitimeout",
    "compression",
    "default_backend",
    "description",
    "disabled",
    "enabled",
    "errorfile",
    "errorloc",
    "errorloc302",
    "errorloc303",
    "force-persist",
    "grace",
    "http-request",
    "http-response",
    "id",
    "ignore-persist",
    "log",
    "maxconn",
    "mode",
    "monitor fail",
    "monitor-net",
    "monitor-uri",
    "option accept-invalid-http-request",
    "option clitcpka",
    "option contstats",
    "option dontlog-normal",
    "option dontlognull",
    "option forceclose",
    "option forwardfor",
    "option http-no-delay",
    "option http-pretend-keepalive",
    "option http-server-close",
    "option http-use-proxy-header",
    "option httpclose",
    "option httplog",
    "option http_proxy",
    "option independent-streams",
    "option log-separate-errors",
    "option logasap",
    "option nolinger",
    "option originalto",
    "option socket-stats",
    "option splice-auto",
    "option splice-request",
    "option splice-response",
    "option tcp-smart-accept",
    "option tcpka",
    "option tcplog",
    "rate-limit sessions",
    "redirect",
    "reqadd",
    "reqallow",
    "reqdel",
    "reqdeny",
    "reqiallow",
    "reqidel",
    "reqideny",
    "reqipass",
    "reqirep",
    "reqisetbe",
    "reqitarpit",
    "reqpass",
    "reqrep",
    "reqsetbe",
    "reqtarpit",
    "rspadd",
    "rspdel",
    "rspdeny",
    "rspidel",
    "rspideny",
    "rspirep",
    "rsprep",
    "tcp-request connection",
    "tcp-request content",
    "tcp-request inspect-delay",
    "timeout client",
    "timeout clitimeout",
    "timeout http-keep-alive",
    "timeout http-request",
    "timeout tarpit",
    "unique-id-format",
    "unique-id-header",
    "use_backend"
  ],
  "listen" => [
    "acl",
    "appsession",
    "backlog",
    "balance",
    "bind",
    "bind-process",
    "block",
    "capture cookie",
    "capture request header",
    "capture response header",
    "clitimeout",
    "compression",
    "contimeout",
    "cookie",
    "default-server",
    "default_backend",
    "description",
    "disabled",
    "dispatch",
    "enabled",
    "errorfile",
    "errorloc",
    "errorloc302",
    "errorloc303",
    "force-persist",
    "fullconn",
    "grace",
    "hash-type",
    "http-check disable-on-404",
    "http-check expect",
    "http-check send-state",
    "http-request",
    "http-response",
    "id",
    "ignore-persist",
    "log",
    "maxconn",
    "mode",
    "monitor fail",
    "monitor-net",
    "monitor-uri",
    "option abortonclose",
    "option accept-invalid-http-request",
    "option accept-invalid-http-response",
    "option allbackups",
    "option checkcache",
    "option clitcpka",
    "option contstats",
    "option dontlog-normal",
    "option dontlognull",
    "option forceclose",
    "option forwardfor",
    "option http-no-delay",
    "option http-pretend-keepalive",
    "option http-server-close",
    "option http-use-proxy-header",
    "option httpchk",
    "option httpclose",
    "option httplog",
    "option http_proxy",
    "option independent-streams",
    "option lb-agent-chk",
    "option ldap-check",
    "option log-health-checks",
    "option log-separate-errors",
    "option logasap",
    "option mysql-check",
    "option pgsql-check",
    "option nolinger",
    "option originalto",
    "option persist",
    "option redispatch",
    "option redis-check",
    "option smtpchk",
    "option socket-stats",
    "option splice-auto",
    "option splice-request",
    "option splice-response",
    "option srvtcpka",
    "option ssl-hello-chk",
    "option tcp-smart-accept",
    "option tcp-smart-connect",
    "option tcpka",
    "option tcplog",
    "option transparent",
    "persist rdp-cookie",
    "rate-limit sessions",
    "redirect",
    "redisp",
    "redispatch",
    "reqadd",
    "reqallow",
    "reqdel",
    "reqdeny",
    "reqiallow",
    "reqidel",
    "reqideny",
    "reqipass",
    "reqirep",
    "reqisetbe",
    "reqitarpit",
    "reqpass",
    "reqrep",
    "reqsetbe",
    "reqtarpit",
    "retries",
    "rspadd",
    "rspdel",
    "rspdeny",
    "rspidel",
    "rspideny",
    "rspirep",
    "rsprep",
    "server",
    "source",
    "srvtimeout",
    "stats admin",
    "stats auth",
    "stats enable",
    "stats hide-version",
    "stats http-request",
    "stats realm",
    "stats refresh",
    "stats scope",
    "stats show-desc",
    "stats show-legends",
    "stats show-node",
    "stats uri",
    "stick match",
    "stick on",
    "stick store-request",
    "stick store-response",
    "stick-table",
    "tcp-request connection",
    "tcp-request content",
    "tcp-request inspect-delay",
    "tcp-response content",
    "tcp-response inspect-delay",
    "timeout check",
    "timeout client",
    "timeout clitimeout",
    "timeout connect",
    "timeout contimeout",
    "timeout http-keep-alive",
    "timeout http-request",
    "timeout queue",
    "timeout server",
    "timeout srvtimeout",
    "timeout tarpit",
    "timeout tunnel",
    "transparent",
    "unique-id-format",
    "unique-id-header",
    "use_backend",
    "use-server"
  ]
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Logging

configure_logger_for, #log, logger_for

Constructor Details

#initialize(opts) ⇒ Haproxy

Returns a new instance of Haproxy.



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# File 'lib/synapse/haproxy.rb', line 496

def initialize(opts)
  super()

  %w{global defaults reload_command}.each do |req|
    raise ArgumentError, "haproxy requires a #{req} section" if !opts.has_key?(req)
  end

  req_pairs = {
    'do_writes' => 'config_file_path',
    'do_socket' => 'socket_file_path',
    'do_reloads' => 'reload_command'}

  req_pairs.each do |cond, req|
    if opts[cond]
      raise ArgumentError, "the `#{req}` option is required when `#{cond}` is true" unless opts[req]
    end
  end

  @opts = opts

  # how to restart haproxy
  @restart_interval = 2
  @restart_required = true
  @last_restart = Time.new(0)

  # a place to store the parsed haproxy config from each watcher
  @watcher_configs = {}
end

Instance Attribute Details

#opts ⇒ Object (readonly)

Returns the value of attribute opts.



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# File 'lib/synapse/haproxy.rb', line 7

def opts
  @opts
end

Instance Method Details

#construct_name(backend) ⇒ Object

used to build unique, consistent haproxy names for backends



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# File 'lib/synapse/haproxy.rb', line 774

def construct_name(backend)
  name = "#{backend['host']}:#{backend['port']}"
  if backend['name'] && !backend['name'].empty?
    name = "#{name}_#{backend['name']}"
  end

  return name
end

#generate_backend_stanza(watcher, config) ⇒ Object 



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# File 'lib/synapse/haproxy.rb', line 646

def generate_backend_stanza(watcher, config)
  if watcher.backends.empty?
    log.warn "synapse: no backends found for watcher #{watcher.name}"
  end

  stanza = [
    "\nbackend #{watcher.name}",
    config.map {|c| "\t#{c}"},
    watcher.backends.shuffle.map {|backend|
      backend_name = construct_name(backend)
      "\tserver #{backend_name} #{backend['host']}:#{backend['port']} #{watcher.haproxy['server_options']}" }
  ]
end

#generate_base_config ⇒ Object

generates the global and defaults sections of the config file



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# File 'lib/synapse/haproxy.rb', line 576

def generate_base_config
  base_config = ["# auto-generated by synapse at #{Time.now}\n"]

  %w{global defaults}.each do |section|
    base_config << "#{section}"
    @opts[section].each do |option|
      base_config << "\t#{option}"
    end
  end

  if @opts['extra_sections']
    @opts['extra_sections'].each do |title, section|
      base_config << "\n#{title}"
      section.each do |option|
        base_config << "\t#{option}"
      end
    end
  end

  return base_config
end

#generate_config(watchers) ⇒ Object

generates a new config based on the state of the watchers



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# File 'lib/synapse/haproxy.rb', line 544

def generate_config(watchers)
  new_config = generate_base_config
  shared_frontend_lines = generate_shared_frontend

  watchers.each do |watcher|
    @watcher_configs[watcher.name] ||= parse_watcher_config(watcher)
    new_config << generate_frontend_stanza(watcher, @watcher_configs[watcher.name]['frontend'])
    new_config << generate_backend_stanza(watcher, @watcher_configs[watcher.name]['backend'])
    if watcher.haproxy.include?('shared_frontend')
      if @opts['shared_frontend'] == nil
        log.warn "synapse: service #{watcher.name} contains a shared frontend section but the base config does not! skipping."
      else
        shared_frontend_lines << validate_haproxy_stanza(watcher.haproxy['shared_frontend'].map{|l| "\t#{l}"}, "frontend", "shared frontend section for #{watcher.name}")
      end
    end
  end
  new_config << shared_frontend_lines.flatten if shared_frontend_lines

  log.debug "synapse: new haproxy config: #{new_config}"
  return new_config.flatten.join("\n")
end

#generate_frontend_stanza(watcher, config) ⇒ Object

generates an individual stanza for a particular watcher



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# File 'lib/synapse/haproxy.rb', line 632

def generate_frontend_stanza(watcher, config)
  unless watcher.haproxy.has_key?("port")
    log.debug "synapse: not generating frontend stanza for watcher #{watcher.name} because it has no port defined"
    return []
  end

  stanza = [
    "\nfrontend #{watcher.name}",
    config.map {|c| "\t#{c}"},
    "\tbind #{@opts['bind_address'] || 'localhost'}:#{watcher.haproxy['port']}",
    "\tdefault_backend #{watcher.name}"
  ]
end

#generate_shared_frontend ⇒ Object

pull out the shared frontend section if any



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# File 'lib/synapse/haproxy.rb', line 567

def generate_shared_frontend
  return nil unless @opts.include?('shared_frontend')
  log.debug "synapse: found a shared frontend section"
  shared_frontend_lines = ["\nfrontend shared-frontend"]
  shared_frontend_lines << validate_haproxy_stanza(@opts['shared_frontend'].map{|l| "\t#{l}"}, "frontend", "shared frontend")
  return shared_frontend_lines
end

#parse_watcher_config(watcher) ⇒ Object

split the haproxy config in each watcher into fields applicable in frontend and backend sections



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# File 'lib/synapse/haproxy.rb', line 600

def parse_watcher_config(watcher)
  config = {}
  %w{frontend backend}.each do |section|
    config[section] = watcher.haproxy[section] || []

    # copy over the settings from the 'listen' section that pertain to section
    config[section].concat(
      watcher.haproxy['listen'].select {|setting|
        parsed_setting = setting.strip.gsub(/\s+/, ' ').downcase
        @@section_fields[section].any? {|field| parsed_setting.start_with?(field)}
      })

    # pick only those fields that are valid and warn about the invalid ones
    config[section] = validate_haproxy_stanza(config[section], section, watcher.name)
  end

  return config
end

#restart ⇒ Object

restarts haproxy



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# File 'lib/synapse/haproxy.rb', line 759

def restart
  # sleep if we restarted too recently
  delay = (@last_restart - Time.now) + @restart_interval
  sleep(delay) if delay > 0

  # do the actual restart
  res = `#{opts['reload_command']}`.chomp
  raise "failed to reload haproxy via #{opts['reload_command']}: #{res}" unless $?.success?
  log.info "synapse: restarted haproxy"

  @last_restart = Time.now()
  @restart_required = false
end

#update_backends(watchers) ⇒ Object

tries to set active backends via haproxy’s stats socket because we can’t add backends via the socket, we might still need to restart haproxy



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# File 'lib/synapse/haproxy.rb', line 662

def update_backends(watchers)
  # first, get a list of existing servers for various backends
  begin
    s = UNIXSocket.new(@opts['socket_file_path'])
    s.write("show stat\n")
    info = s.read()
  rescue StandardError => e
    log.warn "synapse: unhandled error reading stats socket: #{e.inspect}"
    @restart_required = true
    return
  end

  # parse the stats output to get current backends
  cur_backends = {}
  info.split("\n").each do |line|
    next if line[0] == '#'

    parts = line.split(',')
    next if ['FRONTEND', 'BACKEND'].include?(parts[1])

    cur_backends[parts[0]] ||= []
    cur_backends[parts[0]] << parts[1]
  end

  # build a list of backends that should be enabled
  enabled_backends = {}
  watchers.each do |watcher|
    enabled_backends[watcher.name] = []
    next if watcher.backends.empty?

    unless cur_backends.include? watcher.name
      log.debug "synapse: restart required because we added new section #{watcher.name}"
      @restart_required = true
      return
    end

    watcher.backends.each do |backend|
      backend_name = construct_name(backend)
      unless cur_backends[watcher.name].include? backend_name
        log.debug "synapse: restart required because we have a new backend #{watcher.name}/#{backend_name}"
        @restart_required = true
        return
      end

      enabled_backends[watcher.name] << backend_name
    end
  end

  # actually enable the enabled backends, and disable the disabled ones
  cur_backends.each do |section, backends|
    backends.each do |backend|
      if enabled_backends[section].include? backend
        command = "enable server #{section}/#{backend}\n"
      else
        command = "disable server #{section}/#{backend}\n"
      end

      # actually write the command to the socket
      begin
        s = UNIXSocket.new(@opts['socket_file_path'])
        s.write(command)
        output = s.read()
      rescue StandardError => e
        log.warn "synapse: unknown error writing to socket"
        @restart_required = true
        return
      else
        unless output == "\n"
          log.warn "synapse: socket command #{command} failed: #{output}"
          @restart_required = true
          return
        end
      end
    end
  end

  log.info "synapse: reconfigured haproxy"
end

#update_config(watchers) ⇒ Object 



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# File 'lib/synapse/haproxy.rb', line 525

def update_config(watchers)
  # if we support updating backends, try that whenever possible
  if @opts['do_socket']
    update_backends(watchers) unless @restart_required
  else
    @restart_required = true
  end

  # generate a new config
  new_config = generate_config(watchers)

  # if we write config files, lets do that and then possibly restart
  if @opts['do_writes']
    write_config(new_config)
    restart if @opts['do_reloads'] && @restart_required
  end
end

#validate_haproxy_stanza(stanza, stanza_type, service_name) ⇒ Object 



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# File 'lib/synapse/haproxy.rb', line 619

def validate_haproxy_stanza(stanza, stanza_type, service_name)
  return stanza.select {|setting|
    parsed_setting = setting.strip.gsub(/\s+/, ' ').downcase
    if @@section_fields[stanza_type].any? {|field| parsed_setting.start_with?(field)}
      true
    else
      log.warn "synapse: service #{service_name} contains invalid #{stanza_type} setting: '#{setting}', discarding"
      false
    end
  }
end

#write_config(new_config) ⇒ Object

writes the config



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# File 'lib/synapse/haproxy.rb', line 742

def write_config(new_config)
  begin
    old_config = File.read(@opts['config_file_path'])
  rescue Errno::ENOENT => e
    log.info "synapse: could not open haproxy config file at #{@opts['config_file_path']}"
    old_config = ""
  end

  if old_config == new_config
    return false
  else
    File.open(@opts['config_file_path'],'w') {|f| f.write(new_config)}
    return true
  end
end