gitlab with build and push builder stage

gitlab-build-docker-push-builder.yaml

stages:
  - build
  - test
  - deploy
    
variables:
  # disable Docker TLS validation
  DOCKER_TLS_CERTDIR: ""
  DOCKER_HOST: "tcp://localhost:2375"

services:
  - docker:stable-dind

docker-build:
  image: docker:stable
  stage: build
  script:
    - docker pull my-registry/hello-builder:latest || true
    - docker pull my-registry/hello:latest || true

    - docker build --cache-from my-registry/hello-builder:latest --target builder -t hello-builder:latest .
    - docker build --cache-from my-registry/hello:latest --cache-from my-registry/hello-builder:latest -t hello:latest .

    - docker tag hello-builder:latest my-registry/hello-builder:latest    
    - docker tag hello:latest my-registry/hello:${CI_COMMIT_SHORT_SHA}
    - docker tag hello:latest my-registry/hello:latest

    - docker push my-registry/hello-builder:latest
    - docker push my-registry/hello:${CI_COMMIT_SHORT_SHA}
    - docker push my-registry/hello:latest