image: jonoh/docker-buildx-qemu

variables:
  DOCKER_HOST: tcp://docker:2375/
  PLATFORM: local
  DOCKER_IMAGE_TAG: latest
  DOCKER_PREBUILD_CMD: echo

services:
  - docker:dind

.docker_before_script: &docker_before_script
  - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
  - docker pull "$CI_REGISTRY_IMAGE" || true
  - '[[ "$PLATFORM" != "local" ]] && update-binfmts --enable'
  # Use docker-container driver to allow useful features (push/multi-platform)
  - docker buildx create --driver docker-container --use
  - docker buildx inspect --bootstrap

build:
  stage: build
  before_script: *docker_before_script
  script:
    - $DOCKER_PREBUILD_CMD
    - docker buildx build 
      --pull 
      --cache-from "$CI_REGISTRY_IMAGE" 
      --platform "$PLATFORM" 
      -t "$CI_REGISTRY_IMAGE:$DOCKER_IMAGE_TAG" 
      --push $EXTRA_BUILD_ARGS .
  only:
    - master

build-unstable:
  stage: build
  before_script: *docker_before_script
  script:
    - $DOCKER_PREBUILD_CMD
    - docker buildx build 
      --pull 
      --cache-from "$CI_REGISTRY_IMAGE" 
      --platform "$PLATFORM" 
      -t "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG" 
      --push $EXTRA_BUILD_ARGS .
  except:
    - master