/docker-gitlab-ci-runner

Dockerfile to build a base GitLab CI Runner container image.

Primary LanguageShell

Table of Contents

Introduction

Dockerfile to build a GitLab CI Runner base image. You can use this as the base image to build your own runner images. The sameersbn/runner-gitlab project demonstrates its use to build a CI image for GitLab CE.

Version

Current Version: 5.0.0

Installation

Pull the latest version of the image from the docker index. This is the recommended method of installation as it is easier to update image in the future. These builds are performed by the Docker Trusted Build service.

docker pull sameersbn/gitlab-ci-runner:latest

Starting from GitLab CI Runner version 5.0.0, You can pull a particular version of GitLab CI Runner by specifying the version number. For example,

docker pull sameersbn/gitlab-ci-runner:5.0.0

Alternately you can build the image yourself.

git clone https://github.com/sameersbn/docker-gitlab-ci-runner.git
cd docker-gitlab-ci-runner
docker build --tag="$USER/gitlab-ci-runner" .

Quick Start

For a runner to do its trick, it has to first be registered/authorized on the GitLab CI server. This can be done by running the image with the app:setup command.

mkdir -p /opt/gitlab-ci-runner
docker run --name gitlab-ci-runner -it --rm \
	-v /opt/gitlab-ci-runner:/home/gitlab_ci_runner/data \
  sameersbn/gitlab-ci-runner:5.0.0 app:setup

The command will prompt you to specify the location of the GitLab CI server and provide the registration token to access the server. With this out of the way the image is ready, lets get is started.

docker run --name gitlab-ci-runner -d \
	-v /opt/gitlab-ci-runner:/home/gitlab_ci_runner/data \
	sameersbn/gitlab-ci-runner:5.0.0

You now have a basic runner up and running. But in this form its more or less useless. See sameersbn/runner-gitlab to understand how you can use this base image to build a runner for your own projects.

Configuration

Data Store

GitLab CI Runner saves the configuration for connection and access to the GitLab CI server. In addition, SSH keys are generated as well. To make sure this configuration is not lost when when the container is stopped/deleted, we should mount a data store volume at

  • /home/gitlab_ci_runner/data

Volumes can be mounted in docker by specifying the '-v' option in the docker run command.

mkdir /opt/gitlab-ci-runner
docker run --name gitlab-ci-runner -d -h gitlab-ci-runner.local.host \
  -v /opt/gitlab-ci-runner:/home/gitlab_ci_runner/data \
  sameersbn/gitlab-ci-runner:5.0.0

Installing Trusted SSL Server Certificates

If your GitLab server is using self-signed SSL certificates then you should make sure the GitLab server certificate is trusted on the runner for the git clone operations to work.

The default path the runner is configured to look for the trusted SSL certificates is at /home/gitlab_ci_runner/data/certs/ca.crt, this can however be changed using the CA_CERTIFICATES_PATH configuration option.

If you remember from above, the /home/gitlab_ci_runner/data path is the path of the data store, which means that we have to create a folder named certs inside /opt/gitlab-ci-runner/data/ and add the ca.crt file into it.

The ca.crt file should contain the root certificates of all the servers you want to trust. With respect to GitLab, this will be the contents of the gitlab.crt file as described in the README of the docker-gitlab container.

Upgrading

To update the runner, simply stop the image and pull the latest version from the docker index.

docker pull sameersbn/gitlab-ci-runner:5.0.0
docker stop gitlab-ci-runner
docker rm gitlab-ci-runner
docker run --name gitlab-ci-runner -d [OPTIONS] sameersbn/gitlab-ci-runner:5.0.0

References