stages:
  - build
  - push

before_script:
  - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY

Build:
  stage: build
  image: docker:latest
  script:
  - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY
  - docker build --pull -t $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA .
  - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
  services:
  - docker:dind
  tags:
  - docker

Push master:
  stage: push
  only:
    - master
  script:
    - docker pull $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
    - docker tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA $CI_REGISTRY_IMAGE:latest
    - docker push $CI_REGISTRY_IMAGE:latest

Push others:
  stage: push
  except:
    - master
  script:
    - docker pull $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
    - docker tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_NAME
    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_NAME