Puppet – the very basics – Thoughts about technical things

Installing puppet

apt-get -y install ntp dpkg -i puppetlabs-release-pc1-xenial.deb gpg --keyserver pgp.mit.edu --recv-key 7F438280EF8D349F apt-get update

Puppet agent

apt-get install puppet-agent
Edit /etc/puppetlabs/puppet/puppet.conf to add the [master] section

puppet agent -t -d Note this does apply the changes!

Then you can start the puppet service

export PATH=$PATH:/opt/puppetlabs/bin

Puppet server

apt-get install puppetserver
You will probably also want to install apt-get install puppetdb puppetdb-termini and start the puppetdb service after configuring the PostgreSQL database.

To look at clients:
puppet cert list --all

To validate a new client run puppet cert --sign client

Using puppet locally

You don’t need to use a puppet server

Installing modules

The module page will tell you how to do this e.g.
puppet module install module_name --version version

However it’s probably a better idea to use librarian-puppet and define the modules in the Puppetfile

apt-get install ruby
gem install librarian-puppet
cd /etc/puppetlabs/code/environments/production
librarian-puppet init

Once you have edited your Puppetfile

librarian-puppet install

Running a manifest

Manual run

puppet apply --verbose --detailed-exitcodes /etc/puppetlabs/code/environments/production/manifests/manifest.pp

Managed run

The control of what is install is via the file /etc/puppetlabs/code/environments/production/manifests/site.pp
Best practice indicates that you use small modules to define your installation.
Example site.pp

node default {
   include serverdefault
}
node mynode {
}

You can then check it with puppet agent --noop
Note that --test actually applies the changes.

Running over ssh

Not recommended!
For your ssh user create .ssh/config which contains the following:

Host *
	RemoteForward %h:8140 localhost:8140

you can then set up a tunnel via ssh -N client & (assuming that you can ssh to the client as normal!)

On the client you then need to define the puppet server as localhost in /etc/hosts, then puppet agent --test --server puppetserver
as usual.
Then you can run the agent as usual – don’t forget to start the service.

Config

With the current version you should use an environment specific heira.yaml e.g. /etc/puppetlabs/code/environment/production/hiera.yaml

The recommended approach is to use roles and profiles to define how each node should be configured (out of scope of this post) https://docs.puppet.com/pe/2016.5/r_n_p_full_example.html

Encrypted

See https://github.com/voxpupuli/hiera-eyaml but check your puppet version

gem install hiera-eyaml

puppetserver gem install hiera-eyaml

See https://puppet.com/blog/encrypt-your-data-using-hiera-eyaml

Test using something like puppet apply -e '$var = lookup(config::testprop) notify {$var: }' where config::testprop is defined in your secure.eyaml file

Host specific config

The hieradata for this node is defined in the hierarchy as:
/etc/puppetlabs/code/environments/production/hieradata/nodes/nodename.yaml

Groups of nodes

You can use multiple node names or a regex in your site.pp (remember only one node definition will be matched)

Another alternative is to use facts, either existing or custom, to define locations in your hiera hierarchy

If this is too crude then you can use an ENC

A very skeleton python enc program is given below:

#!/usr/bin/env python

import sys
import re
from yaml import load, dump

n = sys.argv[1]


node = {
    'parameters' : {
        "config::myparam" : 'myvalue'
        }
}

dump(node, sys.stdout,
    default_flow_style=False,
    explicit_start=True,
    indent=10 )

Puppet setup

Add the following section to /etc/puppetlabs/puppet/puppet.conf
[main] server = puppetmaster certname = nodename.mydomain environment = production runinterval = 1h

Modules

Detailed module writing is out of scope of this post but a quick start is as follows:

puppet module generate wrighting-serverdefault

Then edit manifests/init.pp

Puppet – the very basics