gitlab-ci.yml: automatically tag the repository

Automatically tag the repository when we bump
the version of container image.

Related-to: TOR-1942

Signed-off-by: Dejan Jesenko <dejan.jesenko@toradex.com>

.gitlab-ci.yml

@@ -27,6 +27,7 @@ services:
 
 stages:
   - lint
+  - repository tagging
   - build-rt-tests
   - build-rt-tests-multiarch
   - deploy
@@ -130,6 +131,29 @@ lint_dockerfile:
     # - DL3029 (do not use --platform flag with FROM)
     - hadolint */Dockerfile --failure-threshold warning --info DL3008 --info DL3029
 
+# Make sure to create access token in "Settings/Access Tokens" section with "write_repository" scope selected.
+# Then in "Settings/CI/CD/" section add a variable with key "GIT_TOKEN" and a value of the access token. Also mask the variable.
+tag:
+  stage: repository tagging
+  needs: []
+  before_script:
+    - if [ -z ${GIT_TOKEN} ]; then echo "Missing variable GIT_TOKEN." && exit 1; fi
+    - TAGS="rt-tests-${RT_TESTS_MAJOR}.${RT_TESTS_MINOR}.${RT_TESTS_PATCH} stress_tests-${RT_TESTS_MAJOR}.${RT_TESTS_MINOR}.${RT_TESTS_PATCH}"
+  script:
+  - apk update && apk add git
+  - git remote set-url origin https://gitlab-ci-token:${GIT_TOKEN}@${CI_REPOSITORY_URL#*@}
+  - for TAG in ${TAGS};
+      do
+        if git ls-remote --tags origin  | grep ${TAG} > /dev/null; then
+          echo "${TAG} tag already exists.";
+        else 
+          echo "Tagging repository with ${TAG} tag.";
+          git tag --delete ${TAG} > /dev/null 2>&1 || true;
+          git tag ${TAG};
+          git push -o ci.skip origin ${TAG}; 
+        fi
+      done
+
 # Enable experimental features in Docker client (experimental feature are needed for manifest)
 .do_docker_experimental: &do_docker_experimental
     - mkdir -p $HOME/.docker