Last Updated: February 25, 2016
·
6.415K
· banjer

Ordering puppet resources with run stages

I've found that I need certain resources, like yum repositories or AD authentication, to be set up on a new host before many other resources can be configured on a Linux host. Enter Puppet run Stages.

class runstages::standard {
    # declare additional run stage
    stage { 'stage01': }
    Stage['stage01'] -> Stage['main']

    # assign classes to stages
    class { 'yumrepos':
      stage => 'stage01',
    }->
    class {'authentication':  # Active Directory auth setup
      stage => 'stage01',
    }->
    class {'hosts':  # hosts file
      stage => 'stage01',
    }
}

Stage['main'] is the default run stage. If you don't explicitly assign a puppet class to a stage, then it will be in the main stage.

In the above example, I've created a custom stage called stage01 and assigned classes to it. As you can see, stage01 is fired before stage main. The -> chaining arrows also ensure ordering. So, the three classes within stage01 are run in a specific order. As an alternative, I could have specified three different run stages for each class, but I prefer grouping all three into a run stage, for scalability.

Then apply the runstages::standard class to your hosts via your External Node Classifier (ENC) e.g. Foreman, if you use one, or in your site manifest. With Foreman, I had to remove the puppet classes yumrepos, authentication, and hosts from my hostgroup(s) otherwise you'll get duplicate declaration warnings.