Managing Infrastructure with Puppet

The Puppet Master

Running a central Puppet Master server will allow us to build configurations that are specific to a particular system and then hand them out to be executed on demand. It can be a central repository for the configuration of all servers in your data center, allowing for the centralized deployment of updates and applications.

Once the Puppet Master is installed, you’ll have an empty Puppet repository in /etc/puppet. When the Puppet Master starts up, the first file it loads is /etc/puppet/manifests/site.pp. Generally this file will include a nodes.pp file as well as set some default parameters. nodes.pp will tell the Puppet Master how to decide what classes it should apply to a system, called a node, when it checks in.

Note

The Puppet Master and agent communicate over tcp port 8140. Make sure that any applicable firewall settings allow communication on that port between the two.

Let’s step through how to set up a node definition and apply a class to it with a central Puppet Master rather than by manually applying the manifest.

First, you’ll need to have both agent and master installed. For simplicity’s sake, these can be on the same system. Then set up a simple /etc/puppet/manifests/site.pp and nodes.pp.

This site.pp includes our nodes.pp and sets up a couple of defaults. The first of these is the filebucket. When Puppet makes some change to the filesystem, such as overwriting a config file with an update, it will make a backup of the original. When we define a filebucket ...