beaker-docker

Beaker library to use docker hypervisor

• How to use this wizardry
  • Nodeset Options
  • Privileged containers
  • Cleaning up after tests
• Working with podman
• Generating a Dockerfile
• Spec tests
• Acceptance tests
• Transfer Notice
• License
• Release Information

How to use this wizardry

This gem that allows you to use hosts with docker hypervisor with beaker.

Beaker will automatically load the appropriate hypervisors for any given hosts file, so as long as your project dependencies are satisfied there's nothing else to do. No need to require this library in your tests.

In order to use a specific hypervisor or DSL extension library in your project, you will need to include them alongside Beaker in your Gemfile or project.gemspec. E.g.

# Gemfile
gem 'beaker', '~> 4.0'
gem 'beaker-docker'
# project.gemspec
s.add_runtime_dependency 'beaker', '~> 4.0'
s.add_runtime_dependency 'beaker-docker'

Nodeset Options

The following is a sample nodeset:

HOSTS:
  el8:
    platform: el-8-x86_64
    hypervisor: docker
    image: centos:8
    docker_cmd: '["/sbin/init"]'
    # Run arbitrary things
    docker_image_commands:
      - 'touch /tmp/myfile'
    dockeropts:
      Labels:
        thing: 'stuff'
      HostConfig:
        Privileged: true
  el7:
    platform: el-7-x86_64
    hypervisor: docker
    image: centos:7
    # EL7 images do not support nested systemd
    docker_cmd: '/usr/sbin/sshd -D -E /var/log/sshd.log'
CONFIG:
  docker_cap_add:
    - AUDIT_WRITE

Privileged containers

Containers are run in privileged mode by default unless capabilities are set.

If you wish to disable privileged mode, simply set the following in your node:

dockeropts:
  HostConfig:
    Privileged: false

Cleaning up after tests

Containers created by this plugin may not be destroyed unless the tests complete successfully. Each container created is prefixed by beaker- to make filtering for clean up easier.

A quick way to clean up all nodes is as follows:

podman rm -f $( podman ps -q -f name="beaker-*" )

Working with podman

If you're using a version of podman that has API socket support then you should be able to simply set DOCKER_HOST to your socket and connect as usual.

You also need to ensure that you're using a version of the docker-api gem that supports podman.

You may find that not all of your tests work as expected. This will be due to the tighter system restrictions placed on containers by podman. You may need to edit the dockeropts hash in your nodeset to include different flags in the HostConfig section.

See the HostConfig portion of the docker API for more information.

Generating a Dockerfile

Usually beaker-docker is used to provision docker instances with beaker. During this step beaker-docker generates a Dockerfile and posts it to the docker daemon API.

There's also a small CLI command to only generate the file:

bundle exec beaker-docker dockerfile archlinux-64

Will generate a local Dockerfile:

FROM archlinux/archlinux
ENV container docker
RUN pacman --sync --refresh --noconfirm archlinux-keyring && pacman --sync --refresh --noconfirm --sysupgrade && pacman --sync --noconfirm curl ntp net-tools openssh && ssh-keygen -A && sed -ri 's/^#?UsePAM .*/UsePAM no/' /etc/ssh/sshd_config && systemctl enable sshd
RUN mkdir -p /var/run/sshd && echo root:root | chpasswd
RUN sed -ri -e 's/^#?PermitRootLogin .*/PermitRootLogin yes/' -e 's/^#?PasswordAuthentication .*/PasswordAuthentication yes/' -e 's/^#?UseDNS .*/UseDNS no/' -e 's/^#?MaxAuthTries.*/MaxAuthTries 1000/' /etc/ssh/sshd_config
EXPOSE 22
CMD ["/sbin/init"]

This works by calling (beaker-hostgenerator](https://github.com/voxpupuli/beaker-hostgenerator?tab=readme-ov-file#beaker-host-generator). So you can provide any host string that's supported by beaker-hostgenerator.

For non-rolling release distros this is usually $os$majorversion-$architecture

beaker-docker dockerfile centos9-64

FROM quay.io/centos/centos:stream9
ENV container docker
RUN dnf clean all && dnf install -y sudo openssh-server openssh-clients chrony && ssh-keygen -A && sed 's@session *required *pam_loginuid.so@session optional pam_loginuid.so@g' -i /etc/pam.d/*
RUN mkdir -p /var/run/sshd && echo root:root | chpasswd
RUN sed -ri -e 's/^#?PermitRootLogin .*/PermitRootLogin yes/' -e 's/^#?PasswordAuthentication .*/PasswordAuthentication yes/' -e 's/^#?UseDNS .*/UseDNS no/' -e 's/^#?MaxAuthTries.*/MaxAuthTries 1000/' /etc/ssh/sshd_config
RUN cp /bin/true /sbin/agetty
RUN dnf install -y cronie crontabs initscripts iproute openssl wget which glibc-langpack-en hostname
EXPOSE 22
CMD ["/sbin/init"]

This requires a running docker daemon. You can also request a containerfile. This will currently generate a Containerfile but with the same content (this may change in the future, depending on the API spec).

Spec tests

Spec test live under the spec folder. There are the default rake task and therefore can run with a simple command:

bundle exec rake test:spec

Acceptance tests

There is a simple rake task to invoke acceptance test for the library:

bundle exec rake test:acceptance

Transfer Notice

This plugin was originally authored by Puppet Inc. The maintainer preferred that Puppet Community take ownership of the module for future improvement and maintenance. Existing pull requests and issues were transferred over, please fork and continue to contribute here.

Previously: https://github.com/puppetlabs/beaker

License

This gem is licensed under the Apache-2 license.

Release information

To make a new release, please do:

• update the version in lib/beaker-docker/version.rb
• Install gems with bundle install --with release --path .vendor
• generate the changelog with bundle exec rake changelog
• Check if the new version matches the closed issues/PRs in the changelog
• Create a PR with it
• After it got merged, push a tag. GitHub actions will do the actual release to rubygems and GitHub Packages