Class: Yast::DNSClass

Inherits:
Module
  • Object
show all
Includes:
Logger
Defined in:
src/modules/DNS.rb

Constant Summary collapse

HOSTNAME_FILE = 
"hostname".freeze
HOSTNAME_PATH = 
"/etc/" + HOSTNAME_FILE

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.define_dns_config_method(name) ⇒ Object

Defines a proxy method to DNS configuration

The idea is to keep DNS.hostname, DNS.nameservers, etc. methods so they can still being used in the UI. This mechanism should be removed in the future, when the widgets are adapted to the new API.

Parameters:

  • name (Symbol) —

    Public method's name



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# File 'src/modules/DNS.rb', line 48

def self.define_dns_config_method(name)
  define_method(name) do
    yast_dns_config.public_send(name)
  end

  define_method("#{name}=") do |value|
    yast_dns_config.public_send("#{name}=", value)
  end
end

.define_hostname_config_method(name) ⇒ Object 



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# File 'src/modules/DNS.rb', line 58

def self.define_hostname_config_method(name)
  define_method(name) do
    yast_hostname_config.public_send(name)
  end

  define_method("#{name}=") do |value|
    yast_hostname_config.public_send("#{name}=", value)
  end
end

Instance Method Details

#default_dhcp_hostname ⇒ Boolean

Default value for #dhcp_hostname based on ProductFeatures and Arch

Returns:

  • (Boolean) —

    value set in features or, if none is set, false just for laptops



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# File 'src/modules/DNS.rb', line 181

def default_dhcp_hostname
  # ProductFeatures.GetBooleanFeature returns false either if the value is
  # false or if it's missing, so let's discard the later case calling
  # ProductFeatures.GetFeature first
  feature_index = ["globals", "dhclient_set_hostname"]
  feature = ProductFeatures.GetFeature(*feature_index)
  # No value for the feature
  if feature.nil? || (feature.respond_to?(:empty?) && feature.empty?)
    !Arch.is_laptop
  else
    ProductFeatures.GetBooleanFeature(*feature_index)
  end
end

#GetHostnameFromGetent(line) ⇒ Object

Handles input as one line of getent output. Returns first hostname found on the line (= canonical hostname).

Parameters:

  • line (String) —

    in /etc/hosts format

Returns:

  • canonical hostname from given line



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# File 'src/modules/DNS.rb', line 112

def GetHostnameFromGetent(line)
  #  line is expected same format as is used in /etc/hosts without additional
  #  comments (getent removes comments from the end).
  #
  #  /etc/hosts line is formatted this way (man 5 hosts):
  #
  #      <ip address> <canonical hostname> [<alias> ...]
  #
  #  - field separators are at least one space and/or tab.
  #  - <canonical hostname>, in generic it is "a computer's unique name". In case
  #  of DNS world, <canonical hostname> is FQDN ("A" record), then <hostname> is
  #  <canonical hostname> without domain part. For example:
  #
  #      foo.example.com. IN A 1.2.3.4
  #
  #  <canonical hostname> => foo.example.com
  #  <hostname> => foo
  #
  canonical_hostname = Builtins.regexpsub(
    line,
    Builtins.sformat("^[%1]+[[:blank:]]+(.*)", IP.ValidChars),
    "\\1"
  )

  canonical_hostname = String.FirstChunk(canonical_hostname, " \t\n")
  canonical_hostname = String.CutBlanks(canonical_hostname)

  if !Hostname.CheckDomain(canonical_hostname) &&
      !Hostname.Check(canonical_hostname)
    Builtins.y2error(
      "GetHostnameFromGetent: Invalid hostname detected (%1)",
      canonical_hostname
    )
    Builtins.y2error("GetHostnameFromGetent: input params - begin")
    Builtins.y2error("%1", line)
    Builtins.y2error("GetHostnameFromGetent: input params - end")

    return ""
  end

  Builtins.y2milestone(
    "GetHostnameFromGetEnt: canonical hostname => (%1)",
    canonical_hostname
  )

  canonical_hostname
end

#IsHostLocal(check_host) ⇒ Boolean

Check if hostname or IP address is local computer Used to determine if LDAP server is local (and it should be checked if required schemes are included Calls Read () function before querying any data NOTE: used in yast2-nis-server, yast2-samba-server, yast2-dhcp-server

Parameters:

  • check_host (String) —

    string hostname or IP address to check

Returns:

  • (Boolean) —

    true if hostname is local host



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# File 'src/modules/DNS.rb', line 223

def IsHostLocal(check_host)
  Read()
  current_dhcp_data = {}
  connections = Yast::Lan.yast_config.connections

  if connections.any?(:dhcp?) || dhcp_hostname
    current_dhcp_data = dhcp_data
    log.info("Got DHCP-configured data: #{current_dhcp_data.inspect}")
  end

  # FIXME: May not work properly in following situations:
  #   - multiple addresses per interface
  #     - aliases in /etc/hosts
  #   - IPADDR=IP/24

  # loopback interface or localhost hostname
  return true if ["127.0.0.1", "::1", "localhost", "localhost.localdomain"].include?(check_host)

  ip_addresses = connections.each_with_object([]) do |conn, res|
    conn.all_ips.each_with_object(res) do |ip, ips|
      address = ip&.address&.address.to_s
      ips << address if !address.empty? && !ips.include?(address)
    end
  end

  # IPv4 address
  if IP.Check4(check_host)
    return true if ip_addresses.include?(check_host) || current_dhcp_data["ip"] == check_host
  # IPv6 address
  elsif IP.Check6(check_host)
    log.debug("TODO make it similar to IPv4 after other code adapted to IPv6")
  # short hostname or FQDN
  elsif check_host.downcase == hostname.to_s.downcase ||
      current_dhcp_data["hostname_short"] == check_host ||
      current_dhcp_data["hostname_fq"] == check_host

    return true
  end
  false
end

#main ⇒ Object 



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# File 'src/modules/DNS.rb', line 78

def main
  Yast.import "UI"
  textdomain "network"

  Yast.import "Lan"
  Yast.import "Arch"
  Yast.import "Hostname"
  Yast.import "IP"
  Yast.import "ProductFeatures"
  Yast.import "Progress"
  Yast.import "Service"
  Yast.import "String"
  Yast.import "FileUtils"
  Yast.import "Stage"
  Yast.import "Report"

  Yast.include self, "network/routines.rb"
  Yast.include self, "network/runtime.rb"

  # Domain Name (not including the host part)
  @domain = ""

  # resolver config file location
  @resolv_conf = "/etc/resolv.conf"

  # True if DNS is already read
  @initialized = false
end

#modified ⇒ Boolean

Determines whether the DNS configuration has been modified

Returns:

  • (Boolean) 


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# File 'src/modules/DNS.rb', line 267

def modified
  system_dns_config.nil? || yast_dns_config != system_dns_config
end

#Read ⇒ Object

Note:

It reads all network settings, including DNS ones.

Reads DNS settings



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# File 'src/modules/DNS.rb', line 198

def Read
  Yast::Lan.Read(:cache)
end

#ResolveIP(ip) ⇒ Object

Resolve IP to canonical hostname

Parameters:

  • ip (String) —

    given IP address

Returns:

  • resolved canonical hostname (FQDN) for given IP or empty string in case of failure.



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# File 'src/modules/DNS.rb', line 164

def ResolveIP(ip)
  getent = SCR.Execute(path(".target.bash_output"), "/usr/bin/getent hosts #{ip.shellescape}")
  exit_code = Ops.get_integer(getent, "exit", -1)

  if exit_code != 0
    Builtins.y2error("ResolveIP: getent call failed (%1)", getent)

    return ""
  end

  GetHostnameFromGetent(Ops.get_string(getent, "stdout", ""))
end

#Write(netconfig_update: true) ⇒ Object

TODO:

Update GUI

Write new DNS and hostname settings Includes Host,NetworkConfig::Write

Parameters:

  • netconfig_update (Boolean) (defaults to: true) —

    Whether 'netconfig update' should be called after writing the DNS configuration or not

Returns:

  • true if success



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# File 'src/modules/DNS.rb', line 208

def Write(netconfig_update: true)
  writer = Y2Network::ConfigWriters::DNSWriter.new
  writer.write(Yast::Lan.yast_config.dns,
    Yast::Lan.system_config.dns,
    netconfig_update: netconfig_update)
  true
end