gitlab-ci.readme.md

Manually provisioning a server with the gitlab-runner

These are rudimentary instructions for setting up a gitlab-runner service on a linux server.

Preconditions:

• Ubuntu 18.04 server (other distros may work as well)
• Git
• Docker

The GitLab project must be configured by a maintainer with the following settings:

Settings --> CI / CD --> Runners --> Disable "Shared Runners" (note the token for later use)

Register the gitlab-runner at gitlab.com

Create a directory to store the registration configuration. This will be used to persist the gitlab-runner configuration received during registration across restarts of the container. The directory will be mounted to /etc/gitlab-runner inside the container.

mkdir -p /opt/eyeo/libadblockplus-gitlab-runner/etc_gitlab-runner

We use the official gitlab-runner image for the registration, for the sake of simplicity. However such schema may not work, in this case please register the corresponding gitlab-runner from the actual runner environment. Run the registration in a one-off docker container:

docker run --rm -t -i \
  -v /opt/eyeo/libadblockplus-gitlab-runner/etc_gitlab-runner:/etc/gitlab-runner \
  gitlab/gitlab-runner \
  register --non-interactive \
  --url "https://gitlab.com/" \
  --registration-token "$REGISTRATION_TOKEN" \
  --description "libadblockplus gitlab-runner on the AA DP team build server" \
  --executor "shell" \
  --tag-list "ubuntu,gitlab-runner" \
  --run-untagged \
  --locked="false"

The following parameter should be replaced with the registration token from the GitLab project CI/CD settings:

--registration-token "$REGISTRATION_TOKEN"

The --tag-list parameter is used to identify or describe the environment within the runtime of the gitlab-runner.

Preparing the gitlab-runner image integration

Clone the gitlab:eyeo/adblockplus/libadblockplus.git into this directory.

cd /opt/eyeo/libadblockplus-gitlab-runner
git clone git@gitlab.com:eyeo/adblockplus/libadblockplus.git

Build custom gitlab-runner image and run it

Switch to the directory of the gitlab-runner Dockerfile:

cd libadblockplus/docker

Build the new image based on the generated configuration

docker build --rm -t eyeo-aa-dp/libadblockplus_gitlab-runner .

Finally, run the gitlab-runner container. In order to provide more flexible disk capacity required for building the projects, we mount a volume eyeo-aa-dp-libadblockplus-vol into /opt/ci where the gitlab-runner will create its working directories:

docker run --rm -t -i \
  -v /opt/eyeo/libadblockplus-gitlab-runner/etc_gitlab-runner:/etc/gitlab-runner \
  -v eyeo-aa-dp-libadblockplus-vol:/opt/ci \
   eyeo-aa-dp/libadblockplus_gitlab-runner

Future improvements

• Automatically start the service after reboot
• Automate this provisioning (using https://gitlab.com/eyeo/devops/ansible-role-gitlab-runner)
• Restrict the gitlab runner to use a limited set of resources
• Investigate triggers for this CI (for example run it just for MR: see https://gitlab.com/gitlab-org/gitlab-ce/issues/25099)
• Investigate use of docker executor instead of shell executor