example

We want to make the following firewall rule to be applyable to different network interfaces (for e.g. different environments) with just one variable:

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firewall { "010-reject-port":
  ensure      => present,
  dport       => [ 80 ],
  destination => $::ipaddress_eth0,
  proto       => 'tcp',
  action      => 'drop',
  iniface     => 'eth0',
}

We can create a $firewall_interface variable and apply it to iniface but how can we ensure that the correct ipaddress factof the corresponding interface is used for destination?

Solution:

Use getvar from the puppetlabs stdlib:

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$firewall_interface = 'eth0'

firewall { "010-reject-port":
  ensure      => present,
  dport       => [ 80 ],
  destination => getvar("::ipaddress_${firewall_interface}"),
  proto       => 'tcp',
  action      => 'drop',
  iniface     => $firewall_interface,
}