Day 24 in the #vDM30in30

Image from https://flic.kr/p/DY38HH

So, we’ve talked about how the RAL is a getter and setter, but let’s talk about a lesser known feature of puppet that uses the RAL: The puppet resource command.

The puppet resource command is basically a CLI for the RAL. Hey, it used to even be called “ralsh”, for RAL Shell.

What it’s doing is using that instances method from before, and running it on the system, and returning the current state as valid Puppet code.

Essentially, it’s a CLI to the getter part of the RAL loop.

Go-getter!

Running it with a given resource name will return all the instances it can find for that resource:

[root@homebox ~]# puppet resource package
package { 'acl':
  ensure => '2.2.51-12.el7',
}
package { 'audit':
  ensure => '2.4.1-5.el7',
}
package { 'audit-libs':
  ensure => '2.4.1-5.el7',
}
package { 'audit-libs-python':
  ensure => '2.4.1-5.el7',
}
package { 'authconfig':
  ensure => '6.2.8-10.el7',
}
... etc

The result it returns is valid Puppet code: you could throw it straight into a Puppet file on your master and start enforcing it, or output it to a puppet run and run Puppet apply on it.

If you give a named argument, it’ll return the details of just that resource:

[root@homebox ~]# puppet resource package sudo
package { 'sudo':
  ensure => '1.8.6p7-17.el7_2',
}

Setter

It’s not just reserved for the getter: you can even use the puppet resource command to manipulate resources as a setter:

[root@homebox ~]# puppet resource package tree ensure=absent
Notice: /Package[tree]/ensure: removed
package { 'tree':
  ensure => 'purged',
}

And not just the ensure, but other fields:

[root@homebox ~]# puppet resource user tree ensure=present shell=/bin/false
Notice: /User[tree]/shell: shell changed '/bin/bash' to '/bin/false'
user { 'tree':
  ensure => 'present',
  shell  => '/bin/false',
}

In Part 4 we’ll talk about how to implement your own RAL-layer for a custom type and provider.