Passing parameters from Hiera

Like the parameter defaults we introduced in the previous chapter, Hiera may be used to provide default values to classes. This feature requires Puppet Version 3 and higher.

Getting ready

Install and configure hiera as we did in Chapter 2, Puppet Infrastructure. Create a global or common yaml file; this will serve as the default for all values.

How to do it...

1. Create a class with parameters and no default values:

   t@mylaptop ~/puppet $ mkdir -p modules/mysql/manifests t@mylaptop ~/puppet $ vim modules/mysql/manifests/init.pp
   class mysql ( $port, $socket, $package ) {
     notify {"Port: $port Socket: $socket Package: $package": }
   }
   

2. Update your common .yaml file in Hiera with the default values for the mysql class:

   ---
   mysql::port: 3306
   mysql::package: 'mysql-server'
   mysql::socket: '/var/lib/mysql/mysql.sock'
   

   Apply the class to a node, you can add the mysql class to your default node for now.

   node default {
     class {'mysql': }
   }
   

3. Run puppet agent and verify the output...