netlogix / docker-puppet-demo

Demo for creating docker images with puppet and packer

Demo for building docker images with puppet and packer

The aim of this demo is to show how building docker images from puppet code can be achieved in a simple and reliable way.

What it does

The demo uses some simple puppet code to provision the docker images to run a simple demo php application.

The Makefile just wraps some longer commands to make them easier to use.

The bin/packer.sh script uses docker-compose to start a puppet server and puppetdb (as dependencies in docker-compose.yml) and then runs packer in a docker container.

Packer starts a docker container from an image defined in the template and vars file and for the base image installs puppet into the container. Afterwards, puppet is run against the puppet server started earlier. The puppet ssl certificates need to be removed as the containers have different hostnames on every run. After packer finished running puppet an image is created from the container.

Requirements

• docker
• docker-compose
• r10k (because it doesn't run well in docker)

Running the demo

1. Install required puppet modules

   r10k puppetfile install

2. Create the base docker image containing puppet and basic adjustments

   make base

3. Create the other docker images which depend on the base image

   make apache-base php-fpm mariadb-base

4. Create the docker images for the demo

   make demo-app1-apache demo-db

5. Run the demo application

   cd demo-app
   docker-compose up
   curl localhost:8080

Future possible improvements

Running tests on the created image

After tagging the image a shell-local provisioner step can be added to run a testsuite using serverspec. After successful test run the image can be tagged latest and pushed to the registry. This is currently broken as of packer 1.6.4 but should be fixed in packer 1.6.5.

Installing puppet in a temporary volume instead of in the image

It should be possible to mount a volume to /opt/puppetlabs into which puppet is installed so the puppet executables are not part of the finished image.