fix tags: avoid MR to overwrite latest

.gitlab-ci.yml

@@ -35,11 +35,18 @@ stages:
         - docker/${IMAGE_NAME}/**/*
         - .gitlab-ci.yml
   script:
-    - export IMAGE_TAG=$IMAGE:$CI_COMMIT_REF_SLUG
+    # main is latest, MR create tag from branch name
+    - export IMAGE_TAG=$IMAGE:${CI_COMMIT_REF_SLUG/main/latest}
     - echo $CI_REGISTRY_USER $CI_REGISTRY $IMAGE_TAG
     - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
     - docker pull $IMAGE:latest || true
-    - docker build --cache-from $IMAGE:latest -t $IMAGE:$CI_COMMIT_SHA -t $IMAGE:$CI_COMMIT_SHORT_SHA -t $IMAGE_TAG -t $IMAGE:latest ./docker/$IMAGE_NAME
+    - >
+      docker build
+      --cache-from $IMAGE:latest
+      -t $IMAGE:$CI_COMMIT_SHA
+      -t $IMAGE:$CI_COMMIT_SHORT_SHA
+      -t $IMAGE_TAG
+      ./docker/$IMAGE_NAME
     - docker push --all-tags $IMAGE
 
 build_all_dockers: