Docker Puppet Agent

This is a basic repository for a docker agent module that can be spun up for testing multiple agents for reproductions. It is a wrapper for the puppetlabs-docker_platform module. The core code leverages a docker image from https://github.com/puppetlabs/puppet-in-docker/master/puppet-agent-ubuntu with the idea of having agents that are deployed through docker.

Preconfiguration

Puppet Enterprise will automatically configure pxp-agent and MCollective, which will not work in these containers. It is advised to remove these docker instances from those classifications by adding virtual != docker to both PE Agent and PE MCollective node groups.

Starting docker on a node

Either configure classification on the master to use the docker module. Below is an example on how to kickstart a node locally with docker and pull the correct agent image. Use the included dockerhost module in this repo to kickstart the host and download the puppet/puppet-agent-ubuntu image.

include dockeragent

Starting a new agent manually

With this module, you should not have to deploy any instances manually, but the following command can be used for testing.

docker run -d --add-host puppet:<Master IP Address> -t puppet/puppet-agent-ubuntu agent --verbose --no-daemonize --summarize

Starting a new agent with puppet code

Leveraging the defined type dockeragent::node you can launch a single instance by sending in the masterip parameter. More parameters can be seen in the pp file.

include dockeragent

# This will manage a single containerized agent
dockeragent::node {'instancename':
  masterip => '1.2.3.4',
}

Running multiple agents with puppet code

Be careful when starting many agents at once. This can lead to massive IO spikes as there is no logic to stagger the puppet agent runs. If you need many agents to be run (20+) I would suggest incrementally adding more between puppet agent -t runs.

include dockeragent

# This will manage 5 containerized agents
class { 'dockeragent::multinodes':
  masterip => '1.2.3.4',
  agents => 10,
}

Running the puppet agent

By default this module configures the containers to run the puppet agent perodically. With testing it may be useful to run the puppet agent ad-hoc. You can do this on a specific container in the environment with the following command.

docker exec -it <container name> puppet agent -t

A simple script to sequentially run puppet agent -t on all of the containers is as follows.

for i in $(docker ps -q); do docker exec -it $i puppet agent -t; done