litmusimage

This repository creates docker image files, for testing puppet modules with services with Puppet Litmus.

The images have initd, systemd or upstart, along with SSH.

Images get uploaded to Docker Hub automatically and are rebuilt nightly if necessary.

Buildable images

IMAGE	TAG	DOCKERFILE	BASE_IMAGE	BASE_IMAGE_TAG
ubuntu	14.04	apt_initd_dockerfile	ubuntu	14.04
ubuntu	16.04	apt_systemd_dockerfile	ubuntu	16.04
ubuntu	18.04	apt_sysvinit-utils_dockerfile	ubuntu	18.04
ubuntu	20.04	apt_sysvinit-utils_dockerfile	ubuntu	20.04
centos	6	yum_initd_dockerfile	centos	6
centos	7	yum_systemd_dockerfile	centos	7
centos	8	yum_systemd_dockerfile	centos	8
scientificlinux	6	yum_initd_dockerfile	scientificlinux/sl	6
scientificlinux	7	yum_systemd_dockerfile	scientificlinux/sl	7
oraclelinux	6	yum_initd_dockerfile	oraclelinux	6
oraclelinux	7	yum_systemd_dockerfile	oraclelinux	7
debian	8	apt_systemd_dockerfile	debian	8
debian	9	apt_systemd_dockerfile	debian	9
debian	10	apt_sysvinit-utils_dockerfile	debian	10

Manual Building

docker build --rm --no-cache -t litmusimage/$IMAGE:$TAG . -f $DOCKERFILE --build-arg BASE_IMAGE_TAG=$BASE_IMAGE_TAG --build-arg OS_TYPE=$BASE_IMAGE

For example with BASE_IMAGE=ubuntu, DOCKERFILE=apt_initd_dockerfile, IMAGE=ubuntu, TAG=14.04, and BASE_IMAGE_TAG=${TAG}

docker build --rm --no-cache -t litmusimage/ubuntu:14.04 . -f apt_initd_dockerfile --build-arg BASE_IMAGE_TAG=14.04 --build-arg OS_TYPE=ubuntu

Push said image

# docker login
docker image push litmusimage/centos:7

Tips and tricks for docker wrangling

# List running and stopped containers
docker container ls -a
# remove a container
docker rm -f ubuntu_14.04-2224
# remove all containers
docker rm -f $(docker ps -a -q)
# jump into a container, force a shell
docker exec -it litmusimage_debian9_-2223 /bin/bash
# attach to a container ( limited by what pid 0 is)
docker attach litmusimage_ubuntu16.04_-2222
# safely exit a container, leaving it running
<ctrl> + p then <ctrl> + q
# get the latest version of the image
docker pull debian:8
# show the history of the image
docker image history litmusimage/ubuntu16.04
# remove all docker images that are on your local machine
docker rmi $(docker images -q)

Add new images

Add/change dockerfile for the new image
Every dockerfile needs a base_image label where the base image id will be stored. This will be used in the nightly build to identify if the base image has been updated.
Change workflows to build the new images
New images will be pushed to dockerhub only on pushes to the main branch, and will be updated nightly in case the base image has changed

Future improvements

Use a centralized file (possibly CSV, JSON or YAML) with the images and corresponding docker build parameters rather than having it duplicated in every workflow.
Optimize building by using fewer layers or using multi-stage builds (needs to take care of correctly basing on base image)
Introduce variants with puppet agent pre-installed for litmus:install_agent