Run docker-compose build in .gitlab-ci.yml

Question

I have a .gitlab-ci.yml file which contains following:

image: docker:latest

services:
  - docker:dind

before_script:
  - docker info
  - docker-compose --version

buildJob:
  stage: build
  tags:
    - docker
  script:
    - docker-compose build

But in ci-log I receive message:

$ docker-compose --version
/bin/sh: eval: line 46: docker-compose: not found

What am I doing wrong?

Answer 1

Following the official documentation:

# .gitlab-ci.yml
image: docker
services:
  - docker:dind    
build:
  script:
    - apk add --no-cache docker-compose
    - docker-compose up -d

Sample docker-compose.yml:

version: "3.7"
services:
  foo:
    image: alpine
    command: sleep 3
  bar:
    image: alpine
    command: sleep 3

We personally do not follow this flow anymore, because you loose control about the running containers and they might end up running endless. This is because of the docker-in-docker executor. We developed a python-script as a workaround to kill all old containers in our CI, which can be found here. But I do not suggest to start containers like this anymore.