Re: [Puppet Users] Deployed but unmanaged file

Brian Gallew
Wed, 29 Jun 2011 16:14:19 -0000

On Jun 29, 2011, at 9:05 AM, Nigel Kersten wrote:

> I''ve long wanted the equivalent of a "conffile" in
Puppet.
>
> e.g. "replace this file if it''s still the same as the one
Puppet put down, but if it''s been modified from the default,
don''t replace it"
>
> I''ve wanted this in the past for things like a user .rc file,
where you want to be able to continually update the default, but not throw away
any customization the user may have done.

SInce I support developer who sometimes want to control the conf files, and
sometimes want Puppet to control them, I created a define:

define managed_file($source = undef, $content = undef) {
  $pdir = inline_template("<%=
name.reverse().split(''/'',2)[1].reverse() %>")
  $basename = inline_template("<%= name.split(''/'')[-1]
%>")

  file {
    "${name}-puppet":
      source => $source, content => $content, ensure => present;
    "${pdir}/README-${basename}":
      ensure => present,
      content => "${name} is managed by Puppet.\n\nIf you need to
edit\n${name}\nand have your changes persist, touch\n${name}.noupdate\nand
Puppet will ignore that file.  When you are done with your\ntesting, please have
your changes put in Puppet and delete the\n${name}.noupdate\nfile.
Thanks.\n\n";
  }

  exec {
    "${name}-sync":
      unless => "test -f ${name}.noupdate || cmp -s ${name}
${name}-puppet",
      command => "/usr/local/bin/rsync -a ${name}-puppet ${name}",
      require => File["${name}-puppet"];
  }
}


And you use it like so:
managed_file {
  "${muledir}/lib/user/system-config.properties":
    content => template("jboss/system-config.properties.erb"),
    require => File["${muledir}/lib/user"],
    notify => Service["/site/mule"];
}

That will create three files in ${muledir}/lib/user:
README-system-config.properties, system-config.properties-puppet, and
system-config.properties.  If one of the developers on a managed system needs to
hand-edit that file, they red the instructions in the README-* and simply touch
system-config.properties.noupdate.  Removing that file re-enables Puppet
management.  As a further benefit, they can trivially see what''s going
to change when they remove the .noupdate file because the -puppet version will
always be Puppet-managed.