Class: VagrantAutoDNS::Cap::RedirectDNS

Inherits:
Object
  • Object
show all
Extended by:
Common
Defined in:
lib/vagrant-autodns/cap/redirect_dns.rb

Constant Summary collapse

PRIVATE_IP = 
/^(192\.168|10\.|169\.254|172\.(1[6-9]|2\d|3[0-1]))/

Class Method Summary collapse

Methods included from Common

iptables_location, run_command

Class Method Details

.redirect_dns(machine) ⇒ Object 



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# File 'lib/vagrant-autodns/cap/redirect_dns.rb', line 17

def self.redirect_dns(machine)
  #Get guest nameserver
  get_nameserver = [
    'grep nameserver /etc/resolv.conf',
    "awk '{print $2}'",
    'head -n1'
  ].join(' | ')
  nameserver = run_command(machine, get_nameserver)

  #Default to use resolvconf if installed
  update_search_domain = if !run_command(machine, 'command -v resolvconf').empty?
    [
      'echo "search $(hostname -d)" >> /etc/resolvconf/resolv.conf.d/base',
      'resolvconf -u'
    ].join(' && ')
  #Else check if dhclient is installed and try that
  elsif !run_command(machine, 'command -v dhclient').empty?
    #Find dhclient.conf location, consider doing this more intelligently
    dhclient_conf_loc = [
      '/etc/dhclient.conf',
      '/etc/dhcp/dhclient.conf',
      '/etc/dhcp3/dhclient.conf',
      #Dump to /dev/null if no conf can be found
      '/dev/null'
    ].map{|v| "ls #{v} 2>/dev/null"}.join(' || ')

    [
      "dhclient_conf_loc=$( #{dhclient_conf_loc} )",
      #Use dhclient to persist changes across reboots
      'echo "prepend domain-search $(hostname -d);" >> $dhclient_conf_loc',
      'sed "s/^search \(.*\)/search $(hostname -d) \1/" /etc/resolv.conf > /tmp/resolv.conf',
      'mv -f /tmp/resolv.conf /etc/resolv.conf'
    ].join(' && ')
  #Else overwrite resolv.conf directly
  else
    [
      'sed "s/^search \(.*\)/search $(hostname -d) \1/" /etc/resolv.conf > /tmp/resolv.conf',
      'mv -f /tmp/resolv.conf /etc/resolv.conf'
    ].join(' && ')
  end
  run_command(machine, update_search_domain)

  #Iptables redirect
  if nameserver =~ PRIVATE_IP
    daemon_port = Daemon.listen_port
    iptables_options_udp = [
      '-t nat', #Type nat
      '-A OUTPUT', #Append to output chain
      '-p udp', #Protocol udp (required to use dport)
      "-d #{nameserver}", #Destination ip
      '--dport 53', #Destination port
      '-j DNAT', #Target DNAT
      "--to-destination #{nameserver}:#{daemon_port}" #New destination
    ].join(' ')
    iptables_options_tcp = iptables_options_udp.gsub('-p udp', '-p tcp')
    run_command(machine, "#{iptables_location(machine)} #{iptables_options_udp}")
    run_command(machine, "#{iptables_location(machine)} #{iptables_options_tcp}")
  end
end