数時間苦闘したのでメモ。

.gitlab-ci.yml

build:
  stage: build
  image: docker:stable
  services:
    - docker:dind
  script:
    - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY
    - docker pull $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG || true
    - docker build --cache-from $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG --tag $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG app
    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG

test:
  stage: test
  image: tmaier/docker-compose:19.03
  services:
    - docker:dind
  script:
    - docker version
    - docker-compose version
    - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY
    - sed -i "s|build:|# build:|" docker-compose.yml
    - sed -i "s|context:|# context:|" docker-compose.yml
    - sed -i "s|app_image|$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG|" docker-compose.yml
    - docker-compose -p $CI_COMMIT_SHA config
    - docker-compose -p $CI_COMMIT_SHA pull
    - docker-compose -p $CI_COMMIT_SHA run test
  after_script:
    - docker-compose -p $CI_COMMIT_SHA down -v
    - docker-compose -p $CI_COMMIT_SHA rm -f

docker-compose.yml

そのまま。
ローカルで test イメージを起動したくないときは docker-compose up -d app などする。

version: "3.0"
services:
  redis:
    image: redis:5.0
    volumes:
      - redis_data:/data

  app:
    build:
      context: app
    image: app_image
    depends_on:
      - redis
    ports:
      - "80:80"
    command: "/app/main.py"

  test:
    image: app_image
    depends_on:
      - app
    volumes:
      - ./:/work:ro
    command: "/work/test.sh"

volumes:
  redis_data:

CI Runner の config.toml

関係する部分を抜粋。

[[runners]]
  name = "xxx"
  url = "xxx"
  token = "xxx"
  executor = "docker"
  [runners.custom_build_dir]
  [runners.docker]
    tls_verify = false
    image = "ubuntu:18.04"
    privileged = true
    volumes = ["/certs/client", "/cache"]

検証環境

CI のログから。

$ docker version
 Client: Docker Engine - Community
  Version:           19.03.5
  API version:       1.40
  Go version:        go1.12.12
  Git commit:        633a0ea838
  Built:             Wed Nov 13 07:22:05 2019
  OS/Arch:           linux/amd64
  Experimental:      false
 Server: Docker Engine - Community
  Engine:
   Version:          19.03.6
   API version:      1.40 (minimum version 1.12)
   Go version:       go1.12.16
   Git commit:       369ce74a3c
   Built:            Thu Feb 13 01:32:22 2020
   OS/Arch:          linux/amd64
   Experimental:     false
  containerd:
   Version:          v1.2.12
   GitCommit:        35bd7a5f69c13e1563af8a93431411cd9ecf5021
  runc:
   Version:          1.0.0-rc10
   GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
  docker-init:
   Version:          0.18.0
   GitCommit:        fec3683
 $ docker-compose version
 docker-compose version 1.25.1, build a82fef0
 docker-py version: 4.1.0
 CPython version: 2.7.16
 OpenSSL version: OpenSSL 1.1.1d  10 Sep 2019