build:
  image: docker:20
  stage: build
  services:
    - docker:20-dind
  variables:
    IMAGE_TAG: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG
  script:
    - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
    - docker buildx build --push --platform linux/amd64 --tag $IMAGE_TAG .
    - docker buildx build --push --platform linux/arm64 --tag $IMAGE_TAG .