Split Docker image build and deployment.

Image is now deployed only on tag creation.

Latest tag was added (better pour image usage)

.gitlab-ci.yml

@@ -5,10 +5,15 @@ image: docker:latest
 variables:
   DOCKER_DRIVER: overlay 
   IMAGE_TAG: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_NAME
+  IMAGE_LATEST: $CI_REGISTRY_IMAGE:latest
 
 services:
 - docker:dind
 
+stages:
+  - build
+  - deploy
+
 before_script:
   - docker info
   - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY
@@ -17,4 +22,12 @@ build:
   stage: build
   script:
     - docker build -t $IMAGE_TAG .
-    - docker push $IMAGE_TAG
+
+deploy:
+  stage: deploy
+  script:
+    - docker build -t $IMAGE_TAG -t $IMAGE_LATEST .
+    - docker push $CI_REGISTRY_IMAGE
+  only:
+    - tags
+