Introduce relative entrypoints and start services after project clone and checkout

Description

~"feature proposal" executordocker

DBish images

Extending build images

  • I now have the case of a Debian based image, which I want to use for executing Ansible scripts for deployments:
    • During testing I want to have make and the nosetests python module, in the "production" image I do not want to have this.
    • However, as the production image starts as root but switches to a specific service user in it's ENTRYPOINT I am not able install additional stuff in the before_script section.
    • So now I have to create an inherited image just for testing, which looks like an overkill.

Problems

  • While I may define entrypoint entries for both service and image this has two problems:
    • There is no easy way to reference a simple shell script which could be used as entrypoint from the cloned project, because you may not reference the directory where the project is found after cloning.
    • So all you may do is restricted to execute one command in the entrypoint
    • If you use one of the above DBs for integration-tests, the automatic script execution of /docker-entrypoint-initdb.d/* is useless, because the order of execution in the docker-executor looks like this:
      • pull service image
      • create service container
      • start service container
      • wait for successful start
      • pull build image
      • create build container
      • clone project via the helper image
      • checkout
      • start build image
      • run build
    • So while $CI_PROJECT_DIR is volume mounted in the service when the service starts, the project is not checked out already. Therefore $CI_PROJECT_DIR is empty at this point.
  • For the build image the situation is a bit better but including a simple shell wrapper as entrypoint is impossible because you may not reference $CI_PROJECT_DIR in the entrypoint.

Proposal

Allow a relative entry point

See mfriedenhagen/gitlab-runner@6071d9e2

Just check whether entrypoint starts with ./ and prepend $CI_PROJECT_DIR, so when I create a file ./initialize-mysql.sh in my project with this content:

#!/bin/sh -e
cp $CI_PROJECT_DIR/mysql-docker-entrypoint-initdb.d/* /docker-entrypoint-initdb.d/
exec /usr/local/bin/docker-entrypoint.sh $*

I may call it like:

image:
  name: mysql
  entrypoint: ["./initialize-mysql.sh"]

Start services after cloning

  • While allowing relative entrypoints would allow an execution of /docker-entrypoint-initdb.d/ for build images for services the order should be like this so that I may copy my init scripts in ./initialize-mysql.sh as seen above:
    • pull service image(s)
    • create service container(s)
    • pull build image
    • create build container
    • clone project via the helper image
    • checkout
    • start service container(s)
    • wait for successful start
    • start build image
    • run build

Links to related issues and merge requests / references

Edited by Mirko Friedenhagen