---
build-test:
    stage: build-test
    only:
        - merge_requests
    tags:
        - docker
    image: docker
    services:
        - name: docker:dind
          alias: dockerhost
    before_script:
        - echo "$DOCKER_PASS" | docker login -u "$DOCKER_USER" --password-stdin "$DOCKER_URL"
    script:
        - |
          docker build --file devops/docker/php/Dockerfile \
            --tag "$PROJECT_IMAGE_TEST" \
            --target=test .
        - docker push "$PROJECT_IMAGE_TEST"
    after_script:
        - docker logout "$DOCKER_URL"
...