docker-compose: setup entrypoint to register runner on start

Instead of having to manually run a command to register the runner,
automatically register the runner on start if the config file does not
exist yet.

Dockerfile

@@ -8,9 +8,9 @@ RUN echo '@edge/testing http://dl-cdn.alpinelinux.org/alpine/edge/testing' >> /e
         gitlab-runner@edge/testing \
     && adduser -D -S -h /home/gitlab-runner gitlab-runner
 
-COPY register-runner /usr/local/bin
+COPY register-runner entrypoint /usr/local/bin/
 
 VOLUME ["/etc/gitlab-runner", "/home/gitlab-runner"]
-ENTRYPOINT ["/usr/bin/gitlab-runner"]
+ENTRYPOINT ["/usr/local/bin/entrypoint"]
 CMD ["run", "--user=gitlab-runner", "--working-directory=/home/gitlab-runner"]
 

README.md

 # gitlab-runner docker image
 
+[![pipeline status](https://gitlab.alpinelinux.org/alpine/infra/docker/gitlab-runner/badges/master/pipeline.svg)](https://gitlab.alpinelinux.org/alpine/infra/docker/gitlab-runner/commits/master)
+
 This will create a docker image for running a gitlab runner on Alpine Linux on
 all the architectures that Alpine Linux supports.
 
 ## Starting the runner
 
-To run the container, 1 required and 2 optional volumes need to be attached:
-
-* docker socket (/var/run/docker.sock)
-* conf dir (/etc/alpine-runner)
-* home dir (/home/gitlab-runner)
-
-For example:
-
-```sh
-docker run -d \
-    -v /srv/gitlab-runner/conf:/etc/gitlab-runner \
-    -v /srv/gitlab-runner/home:/home/gitlab-runner \
-    -v /var/run/docker.sock:/var/run/docker.sock \
-    gitlab-runner
-```
-
-You can execute `./run` to run this command
-
-## Register the runner
-
-There is a `./register-runner` command available in the container to register it.
-
-To execute it, use the following command:
+There is a `docker-compose.yml` file included that starts up the runner. The
+registration of the runner will be done automatically, but you need to modify
+the file to specify some parameters:
 
-```sh
-docker exec -e ARCH=<arch> -e GITLAB_REGISTER_TOKEN=<token> <container> register-runner
-```
+* `<token>` - The gitlab registration token (you can find it in the admin pannel
+    under runners)
+* `<arch>`  - The architecture for this runner (used as a description and tag).
 
-* `ARCH` is added as a tag on the runner
-* `GITLAB_REGISTER_TOKEN` is a token you can find under `Settings > CI / CD > Runners`
-  of a specific project or under `Admin > Overview > Runners`.
+Then run `docker-compose up -d` and the runner should be running.

docker-compose.yml

@@ -6,3 +6,6 @@ services:
       - /srv/gitlab-runner/conf:/etc/gitlab-runner
       - /srv/gitlab-runner/home:/home/gitlab-runner
       - /var/run/docker.sock:/var/run/docker.sock
+    environment:
+      GITLAB_REGISTRATION_TOKEN: <token>
+      ARCH: <arch>

entrypoint

+#!/bin/sh
+
+if [ ! -f /etc/gitlab-runner/config.toml ]; then
+    if [ -z "$GITLAB_REGISTRATION_TOKEN" ] || [ "$GITLAB_REGISTRATION_TOKEN" = '<token>' ]; then
+        echo "Runner is not configured. Please provide 'GITLAB_REGISTRATION_TOKEN'"
+        exit 1
+    fi
+    register-runner || exit $?
+fi
+
+exec gitlab-runner "$@"

register-runner

 #!/bin/sh
 
+echo "-> Registering runner $ARCH"
+
 gitlab-runner register \
   --non-interactive \
   --url "https://gitlab.alpinelinux.org/" \
-  --registration-token "$GITLAB_REGISTER_TOKEN" \
+  --registration-token "$GITLAB_REGISTRATION_TOKEN" \
   --executor "docker" \
   --docker-image alpine:latest \
   --description "docker-runner ($ARCH)" \
@@ -13,3 +15,11 @@ gitlab-runner register \
   --access-level="not_protected" \
   --docker-helper-image alpinelinux/gitlab-runner-helper:latest \
   --docker-volumes /var/run/docker.sock:/var/run/docker.sock
+
+status=$?
+if [ $status -eq 0 ]; then
+    echo "-> Registration success"
+else
+    echo "-> Something went wrong"
+    exit $status
+fi