Docker Gitlab Setup

Environment Variables

Copy /gitlab/sample.env, adjust the variables and save the file as .env

VIRTUAL_HOST=example.com
EXTERNAL_URL=https://example.com
LOGIN_LABEL='EXAMPLE LOGIN'
ASSERTION_CONSUMER_SERVICE_URL='https://example-gitlab.com/users/auth/saml/callback'
IDP_CERT_FINGERPRINT=''
IDP_SSO_TARGET_URL='https://example-keycloak/auth/realms/example-realm/protocol/saml/clients/gitlab'
ISSUER='gitlab'
PAGES_HOST=pages.example.com
REGISTRY_HOST=registry.example.com
REGISTRY_PORT=5000

Gitlab Environment Variables

• VIRTUAL_HOST - The domain of your gitlab host.
• EXTERNAL_URL - The full external URL of your gitlab host.

Keycloak Environment Variables

These variables can be omitted if you don't use Keycloak as Authentication Provider

• LOGIN_LABEL - Text of the Login Button for Single Sign On with Keycloak as Authentication Provider
• ASSERTION_CONSUMER_SERVICE_URL- This is the SAML callback URL of Keycloak
• IDP_CERT_FINGERPRINT - The Keycloak Realm Cert retrieved from the Realm Settings Page. Use https://www.samltool.com/fingerprint.php to convert the X.509 public certificate to a fingerprint.
• IDP_SSO_TARGET_URL - The Identity Provide Single Sign On URL
• ISSUER - defines the client requesting access - in this case the client is called gitlab

Gitlab Pages Environment Variables

• PAGES_HOST - the pages domain used by gitlab to serve pages

Gitlab Docker Registry Environment Variables

• REGISTRY_HOST - Domain of the registry, can be omitted if you use the domain of gitlab and a different port instead
• REGISTRY_PORT - The port of the registry - only needed if you don't use a dedicated registry domain.

Gitlab Pages

TLS/SSL Settings

Wildcard Certificates

To get SSL working with Gitlab Pages you will need Wildcard Certifcates

• Install Certbot and generate Wildcard Certs. https://community.letsencrypt.org/t/getting-wildcard-certificates-with-certbot/56285
• Bind mount certs in container defined in /gitlab/docker-compose.yml

volumes:
  - /etc/letsencrypt:/etc/letsencrypt:ro

• Set Gitlab Pages settings in /gitlab/docker-compose.yml

 gitlab_pages['inplace_chroot'] = true
 pages_external_url 'https://${PAGES_HOST}'
 pages_nginx['redirect_http_to_https'] = true
 pages_nginx['ssl_certificate'] = "/etc/letsencrypt/live/${PAGES_HOST}/fullchain.pem"
 pages_nginx['ssl_certificate_key'] = "/etc/letsencrypt/live/${PAGES_HOST}/privkey.pem"

Gitlab Registry

Settings in /gitlab/docker-compose.yml

gitlab_rails['registry_enabled'] = true
gitlab_rails['registry_path'] = "/var/opt/gitlab/gitlab-rails/shared/registry"

Disable/Enable registry for all projects

If set to true the registry will be a standard feature for all projects. (This is the default)

 gitlab_rails['gitlab_default_projects_features_container_registry']= false # Make Registry a default feature for all projects

Run Gitlab with Docker Compose

docker-compose up

Gitlab Runner

The Gitlab Runner container can run on any host. In this case it's runnning on the same Docker Host as the gitlab instance.

Environment Variables

• Copy sample.env and save as .env
• Add the domain of your Gitlab host.
• Add the Docker IP of your Gitlab container (Only needed if Gitlab Runner is on the same host as Gitlab)

GITLAB_HOST=gitlab.example.com
GITLAB_CONTAINER_IP=172.20.0.2

Docker Compose

version: '3'
services:
  gitlab-runner:
    build: .
    container_name: gitlab-runner
    restart: always
    volumes:
      - /srv/gitlab-runner:/etc/gitlab-runner
      - ./config.toml:/etc/gitlab-runner/config.toml
      - /var/run/docker.sock:/var/run/docker.sock
    extra_hosts:
      - "${GITLAB_HOST}:${GITLAB_CONTAINER_IP}" # Only needed if running on the same host as Gitlab!
    network_mode: host

networks:
  default:
    external:
      name: gitlab_gitlab-net

Example Docker in Docker Configuration

concurrent = 1
check_interval = 0

[session_server]
  session_timeout = 1800

[[runners]]
  name = "docker-runner"
  url = "example.com"
  token = ""
  executor = "docker"
  [runners.docker]
    tls_verify = false
    image = "docker:stable"
    privileged = false
    disable_entrypoint_overwrite = false
    oom_kill_disable = false
    disable_cache = false
    volumes = ["/cache"]
    shm_size = 0
    extra_hosts=["example.com:172.20.0.2"]
  [runners.cache]
    [runners.cache.s3]
    [runners.cache.gcs]

• Copy /gitlab-runner/config-sample.toml, adjust the settings to your needs and save it as config.toml.
• The external_hosts entry is only needed if Gitlab Runner is running on the same Docker host as Gitlab.
• Retrieve the token from the admin runners settings page on your gitlab instance.

Running on the same Docker host

• Make sure the gitlab container is up and runnning.
• Get the internal Docker IP of the gitlab container with docker inspect gitlab
• Adjust the IP under external_hosts in the config.toml - this has to be the internal Docker IP of the gitlab container!

TLS/SSL

Gitlab Runner needs the Gitlab certificates to securly connect to Gitlab.

• Create a certs directory in /gitlab-runner (/gitlab-runner/certs).
• Copy the gitlab yourdomain.crt and yourdomain.keyfrom the host directory /srv/gitlab/ssl to the certs folder you created beforehand.

Run Gitlab Runner for the first time

docker-compose up --build