Even if you manage just a handful or two of servers, Puppet can already help you to save loads of time and ensures all your systems run in the desired state.

Somehow, I could not find very many or good manuals on how to set up your own (basic) Puppet server on Debian, so I decided to write my own.

The installation in Debian is – as always in Debian – straight forward. Just run an

apt install puppet-agent puppetserver vim-puppet

That last package is not really needed but comes in really handy when editing your Puppet manifests in vim and you want syntax highlighting. While this would be more needed on a git client it also is nice to have on the Puppet server.

As for the main configuration file /etc/puppet/puppet.conf I leave the Debian standard for what it is.

Your manifests should be in /etc/puppet/code/ and the basic structure looks like this:

/etc/puppet/code
            ├── environments
            │   └── production
            │       └── manifests
            └── modules
                ├── module1
                │   ├── examples
                │   ├── files
                │   └── manifests
                ├── module2
                │   ├── examples
                │   ├── files
                │   └── manifests
                └── moduleX
                    ├── examples
                    ├── files
                    └── manifests

Each manifests directory contains at least your init.pp and possibly other Puppet files, except the environment manifest. The /etc/puppet/code/environments/production/manifests/site.pp very basically looks like this:

# DeskTux main Puppet Configuration
include module1
include module2
include moduleX

In the modules, the files directory is not necessary unless you have files to manage and the examples directory should contain a basic init.pp that looks like this:

include moduleX

That way, you can easily test the code of that module by using puppet apply -t init.pp.

Of course, before testing your code, you should first run it through puppet parser validate and puppet-lint. However, this is not a Puppet code manual, you should check their excellent documentation for that.

Of course, your Puppet server will be useless if it only manages itself. To connect clients to your Puppet server, make sure it is reachable on port 8140/TCP (both IPv4 and IPv6 work).

On the client, install Puppet by running apt install puppet-agent (and enable it in systemctl, or write a manifest for that ). Then edit the /etc/puppet/puppet.conf and add this section:

[agent]
server = your.puppet.server

Afterwards, run puppet agent -t. This will create a certificate request on the Puppet server. There, run puppetserver ca list and you will get an output similar to this:

root@puppet:~ # puppetserver ca list
  "client.system.tld" (SHA256) 00:11:22:33:44:55:66:77:88:99:AA:BB:CC:DD:EE:FF:00:11:22:33:44:55:66:77:88:99:AA:BB:CC:DD:EE:FF

To accept that certificate just run

puppetserver ca sign --certname <client.system.tld>

and you are good to go. From now on, that system will be managed by your Puppet server. To test this you can run a puppet agent -t on the client.

In case you need to remove (decommission) a client, you can list all available certificates with

puppetserver ca list --all

and then

puppetserver ca clean --certname <client.name.tld>

Don't forget to remove that client from backup and monitoring

Now, it might be a good idea to manage your Puppet code from your workstation using git. That way you do not need to log in to the Puppet server all the time to make changes to your code as root.