Try caching images in a local registry before pushing

.gitlab-ci.yml

@@ -1,5 +1,8 @@
 image: docker:19.03.12
 
+stages:
+  - docker
+
 variables:
   # When using dind service, we need to instruct docker to talk with
   # the daemon started inside of the service. The daemon is available
@@ -19,20 +22,46 @@ variables:
   # Use TLS https://docs.gitlab.com/ee/ci/docker/using_docker_build.html#tls-enabled
   DOCKER_HOST: tcp://docker:2376
 
+  # Support caching images between jobs
+  CI_LOCAL_REGISTRY_IMAGE: "registry:5000"
+#  CI_LOCAL_REGISTRY_USER: registry
+#  CI_LOCAL_REGISTRY_PASSWORD: thisismyregistry
+
 services:
   - docker:19.03.12-dind
+  - name: registry:2
+    alias: registry
 
-
+# Login to job registry and publish registry
 before_script:
   - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
 
-build:
-  stage: build
+# Make sure we can build a docker image
+# It's pushed to the pipeline-local registry which acts as a cache
+build_docker:
+  stage: docker
   script:
     - docker pull $CI_REGISTRY_IMAGE:latest || true
-    - docker build --cache-from $CI_REGISTRY_IMAGE:latest --tag $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG --tag $CI_REGISTRY_IMAGE:latest .
+    - docker build --cache-from $CI_REGISTRY_IMAGE:latest --tag $CI_LOCAL_REGISTRY_IMAGE:$CI_COMMIT_SHORT_SHA --tag $CI_LOCAL_REGISTRY_IMAGE:latest .
+    - docker push $CI_LOCAL_REGISTRY_IMAGE:$CI_COMMIT_SHORT_SHA
+    - docker push $CI_LOCAL_REGISTRY_IMAGE:latest
+
+test_pull_local_docker:
+  stage: docker
+  script:
+    - docker pull $CI_LOCAL_REGISTRY_IMAGE:$CI_COMMIT_SHORT_SHA
+
+push_docker:
+  stage: docker
+  script:
+    - docker pull $CI_LOCAL_REGISTRY_IMAGE:$CI_COMMIT_SHORT_SHA || true
+    - docker tag $CI_LOCAL_REGISTRY_IMAGE:$CI_COMMIT_SHORT_SHA $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG
+    - docker tag $CI_LOCAL_REGISTRY_IMAGE:$CI_COMMIT_SHORT_SHA $CI_REGISTRY_IMAGE:latest
     - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG
     - docker push $CI_REGISTRY_IMAGE:latest
-
+#    - docker pull $CI_REGISTRY_IMAGE:latest || true
+#    - docker build --cache-from $CI_REGISTRY_IMAGE:latest --tag $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG --tag $CI_REGISTRY_IMAGE:latest .
+#    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG
+#    - docker push $CI_REGISTRY_IMAGE:latest
   only:
     - tags