Use a manual job to trigger a selective build/push

.gitlab-ci.yml

@@ -17,43 +17,51 @@ stages:
 variables:
   DOCKER_DRIVER: overlay2
   DOCKER_HOST: tcp://docker:2375
-  FORCE_BUILD: "false"
+
+# Run test job always
+.test:
+  stage: test
+  rules:
+    - when: always
+
+# Run build job only on a default branch when triggered manually
+.build:
+  stage: build
+  rules:
+    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH
+      when: manual  
 
 .test_build: &test_build
-  stage: test
+  extends: .test
   script:
     # Hack to set an array in /bin/sh
     # http://unix.stackexchange.com/a/137571
     - set -- $CI_JOB_NAME
-    - docker build -f "Dockerfile.$1" .
-  except:
-    - master
+    - docker pull "$CI_REGISTRY_IMAGE:$1" || true
+    - docker build --from-cache="$CI_REGISTRY_IMAGE:$1" -f "Dockerfile.$1" .
 
 .build_and_deploy: &build_and_deploy
-  stage: build
+  extends: .build
   script:
-    - docker build --label "ci_pipeline_url=$CI_PIPELINE_URL" --label "ci_job_url=$CI_JOB_URL" -t "$CI_REGISTRY_IMAGE:$CI_JOB_NAME" -f "Dockerfile.$CI_JOB_NAME" .
+    - docker pull "$CI_REGISTRY_IMAGE:$1" || true
+    - docker build --from-cache="$CI_REGISTRY_IMAGE:$1" --label "ci_pipeline_url=$CI_PIPELINE_URL" --label "ci_job_url=$CI_JOB_URL" -t "$CI_REGISTRY_IMAGE:$CI_JOB_NAME" -f "Dockerfile.$CI_JOB_NAME" .
     - docker push "$CI_REGISTRY_IMAGE:$CI_JOB_NAME"
-  only:
-    - master
 
 .test_custom: &test_custom
-  stage: test
+  extends: .test
   script:
     # Hack to set an array in /bin/sh
     # http://unix.stackexchange.com/a/137571
     - set -- $CI_JOB_NAME
     - ./scripts/custom-docker-build $1
-  except:
-    - master
+  rules:
+    - when: always
 
 .build_and_deploy_custom: &build_and_deploy_custom
-  stage: build
+  extends: .build
   script:
     - ./scripts/custom-docker-build $CI_JOB_NAME --label "ci_pipeline_url=$CI_PIPELINE_URL" --label "ci_job_url=$CI_JOB_URL" -t "$CI_REGISTRY_IMAGE:$CI_JOB_NAME"
-    - push_if_needed "$CI_REGISTRY_IMAGE:$CI_JOB_NAME"
-  only:
-    - master
+    - docker push "$CI_REGISTRY_IMAGE:$CI_JOB_NAME"
 
 # Tests