image: docker:stable

variables:
  DOCKER_HOST: tcp://docker:2375/
  DOCKER_DRIVER: overlay2

services:
  - docker:dind

stages:
  - build

build:
  stage: build
  script:
    - docker build -t $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG .
    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG
  only:
    - tags

after_script:
  - docker images --filter "dangling=true" -q --no-trunc | xargs -r docker rmi