How to install and use Puppet

Note:
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Puppet is a cross-platform framework for system administrators to perform common tasks using code.

The code can perform a variety of tasks, from installing new software, to checking file permissions, to updating user accounts. Puppet is used from the initial installation of a system and throughout the system’s life cycle. In most circumstances, Puppet will be used in a client/server configuration.

This page will demonstrate how to install and configure Puppet in a client/server configuration, with the simple example of installing Apache using Puppet.

Pre-configuration

Before configuring Puppet, you may want to add a DNS CNAME record for puppet.example.com, where example.com is your domain.

By default, Puppet clients check DNS for puppet.example.com as the puppet server name, or Puppet Master. See Domain Name Server for more details.

If you do not want to use DNS, you can add entries to the server and client /etc/hosts file. For example, in the Puppet server’s /etc/hosts file add:

127.0.0.1 localhost.localdomain localhost puppet
192.168.1.17 puppetclient.example.com puppetclient

On each Puppet client, add an entry for the server:

192.168.1.16 puppetmaster.example.com puppetmaster puppet

Note:
Replace the example IP addresses and domain names above with your actual server and client addresses and domain names.

Install Puppet

To install Puppet, run the following command in a terminal on the server:

sudo apt install puppetmaster

On the client machine, or machines, enter:

sudo apt install puppet

Configure Puppet

Create a folder path for the Apache2 class:

sudo mkdir -p /etc/puppet/modules/apache2/manifests

Now setup some resources for Apache2. Create a file /etc/puppet/modules/apache2/manifests/init.pp containing the following:

class apache2 {
  package { 'apache2':
    ensure => installed,
  }

  service { 'apache2':
    ensure  => true,
    enable  => true,
    require => Package['apache2'],
  }
}

Next, create a node file /etc/puppet/code/environments/production/manifests/site.pp with:

node 'puppetclient.example.com' {
   include apache2
}

Note:
Replace puppetclient.example.com with your Puppet client’s host name.

The final step for this simple Puppet server is to restart the daemon:

sudo systemctl restart puppetmaster.service

Now everything is configured on the Puppet server, it is time to configure the client.

First, configure the Puppet agent daemon to start. Edit /etc/default/puppet, changing START to yes:

START=yes

Then start the service:

sudo systemctl start puppet.service

View the client cert fingerprint:

sudo puppet agent --fingerprint

Back on the Puppet server, view pending certificate signing requests:

sudo puppet cert list

On the Puppet server, verify the fingerprint of the client and sign the puppetclient cert:

sudo puppet cert sign puppetclient.example.com

On the Puppet client, run the puppet agent manually in the foreground. This step isn’t strictly necessary, but it is the best way to test and debug the puppet service.

sudo puppet agent --test

Check /var/log/syslog on both hosts for any errors with the configuration. If all goes well the Apache2 package and it’s dependencies will be installed on the Puppet client.