.gitlab-ci.yml

image: docker:stable

stages:
- build

before_script:
   - echo -n $CI_JOB_TOKEN | docker login -u gitlab-ci-token --password-stdin $CI_REGISTRY

build:
  stage: build
  script:
    - docker pull $CI_REGISTRY_IMAGE:latest || true
    - if [ $CI_COMMIT_TAG != '' ]; then 
      docker build --cache-from $CI_REGISTRY_IMAGE:latest
      --tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHORT_SHA 
      --tag $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG
      --tag $CI_REGISTRY_IMAGE:latest .
      else
      docker build --cache-from $CI_REGISTRY_IMAGE:latest
      --tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHORT_SHA --tag $CI_REGISTRY_IMAGE:latest .
      fi
    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHORT_SHA
    - docker push $CI_REGISTRY_IMAGE:latest
    - if [ $CI_COMMIT_TAG != '' ]; then docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG ;fi