Getting ready

If your Puppet manifests aren't already in Git, follow the steps in Managing your manifests with Git.

You'll need a second machine to check out a copy of your Puppet repo. If you're using EC2 instances, create another instance, and call it something like cookbook2.

How to do it...

Follow these steps:

How it works...

We've created a new working copy of the Puppet repo on the new machine:

ubuntu@cookbook2:~$ git clone git@github.com:bitfield/cookbook.git puppet

However, before we can run Puppet, we have to create a node declaration for the cookbook2 node:

node 'cookbook', 'cookbook2' {
  ...
}

Now, we apply the manifest:

ubuntu@cookbook2:~/puppet$ sudo puppet apply manifests/site.pp

Puppet finds the node declaration for cookbook2 and applies the same manifest that we used before on cookbook:

Notice: /Stage[main]//Node[cookbook2]/File[/tmp/hello]/ensure:
 defined content as '{md5}a7966bf58e23583c9a5a4059383ff850'

There's more...

Having scaled your Puppet infrastructure from one machine to the other, you can now extend it to as many as you like! All you need to do is check out the Git repo on a machine, and run puppet apply.

This is a great way to add Puppet management to your existing machines without lots of complicated setup, or using an extra machine to serve as a Puppet Master. Many of my clients have switched to using a Git-based infrastructure because it's simpler, easier to scale, and easier to maintain.

A refinement which you might like to consider is having each machine automatically pull changes from GitHub and apply them with Puppet. Then all you need to do is push a change to GitHub, and it will roll out to all your Puppet-managed machines within a certain time. We'll see how to do this in the following sections.