Getting started with Puppet

What is Puppet? Puppet is a config management tool that helps automating, provisioning and mange the infrastructure using the puppet agent to connect to the server (master). The Files used by puppet to configure are saved in manifests.

What you will need is fully configured private DNS for your infrastructure providing forward and reverse zones. Otherwise you will have to resolv all names using entries in /etc/hosts which gets very hard to manage really fast. You will also need to have port 8140/tcp open in your server's firewall.
In my case, I'll be using the hostnames puppetmaster.archyslife.lan - 172.31.10.40 and client01.archyslife.lan - 172.31.10.50.

Important: There needs to be a dns-record (A) named puppet.yourdomain.tld which points to your master server.
If you are using FreeIPA and the integrated DNS, you can simply run:

 [archy@ipa01 ~]$ ipa dnsrecord-add archyslife.lan puppet --a-ip-address=172.31.10.40  

With that said, let's get started.

First we will have to install the puppet repo with this command:

 [archy@puppetmaster ~]$ sudo rpm -ivh https://yum.puppetlabs.com/puppetlabs-release-pc1-el-7.noarch.rpm  

With the repo installed, continue installing the puppetserver-package.

 [archy@puppetmaster ~]$ yum -y install puppetserver  

By default puppet has 2GB RAM allocated for its Java-VM. If you want to change that, edit /etc/sysconfig/puppetserver to look like the following:

 JAVA_ARGS="-Xms1g -Xmx1g"  

save and exit.

You can now start and enable the puppetserver by using systemd.

 [archy@puppetmaster ~]$ sudo systemctl start puppetserver.service  
 [archy@puppetmaster ~]$ sudo systemctl enable puppetserver.service  

Make sure puppet is running as master.

 [archy@puppetmaster ~]$ sudo /opt/puppetlabs/bin/puppet master  

Now install the client to your client-machine.

 [archy@puppetmaster ~]$ sudo yum -y install puppet-agent  

and activate it using the following command:

 [archy@puppetmaster ~]$ sudo /opt/puppetlabs/bin/puppet resource service puppet ensure=running enable=true  

The clients are authenticated to the puppet server using certificates signed by the master-puppet server. In order to register a client to it, we will have to submit a signing request.
You can do that by running the following command:

 [archy@puppetmaster ~]$ sudo /opt/puppetlabs/bin/puppet agent --server puppetmaster.archyslife.lan --waitforcert 30 --test  

To make the registration process complete, we will have to sign the request and add the client.
Run this command on the master-server.

 [archy@puppetmaster ~]$ sudo /opt/puppetlabs/bin/puppet cert --list  

to list the signing requests and

 [archy@puppetmaster ~]$ sudo /opt/puppetlabs/bin/puppet cert --sign client01.archyslife.lan  

to sign the client and finish the registration.

It's now time to create our first manifest on the master  and test the connection.

 [archy@puppetmaster ~]$ sudo vim /etc/puppetlabs/code/enviroments/production/manifests/hello_world.pp  

Content of the file:

 file {'/var/hello_world_puppet':  
   ensure => present,  
   mode => '0644',  
   content => "This file was created by using a puppet-manifest.\n",  
   }  

Push the file to the clients

 [archy@puppetmaster ~]$ sudo /opt/puppetlabs/bin/puppet apply /etc/puppetlabs/code/enviroments/production/manifests/hello_world.pp  

By default, puppet fetches the configuration changes every 30 minutes,
you can immediatly fetch the published manifests on clients by running

 [archy@puppetmaster ~]$ sudo /opt/puppetlabs/bin/puppet agent --test  

And because we pushed our manifest earlier, there should be a new file created under /var named hello_world_puppet.

Feel free to comment and / or suggest a topic.