ci(gitlab): lint dockerfile; build container image and push to gitlab and harbor registry

.gitlab-ci.yml

+---
+workflow:
+  rules:
+    - if: $CI_MERGE_REQUEST_IID
+    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH
+    - if: $CI_COMMIT_TAG
+
+stages:
+  - test
+  - build
+
+
+lint dockerfile:
+  stage: test
+  image: hadolint/hadolint:latest-debian
+  before_script:
+    - mkdir -p reports
+  script:
+    - hadolint --format gitlab_codeclimate Dockerfile > reports/hadolint-$(md5sum Dockerfile | cut -d" " -f1).json
+  artifacts:
+    name: "$CI_JOB_NAME artifacts from $CI_PROJECT_NAME on $CI_COMMIT_REF_SLUG"
+    when: always
+    reports:
+      codequality:
+        - "reports/*"
+    paths:
+      - "reports/*"
+  rules:
+    - if: $CI_MERGE_REQUEST_IID
+      changes:
+        - Dockerfile
+
+build container image:
+  stage: build
+  image:
+    name: gcr.io/kaniko-project/executor:debug
+    entrypoint: [""]
+  script:
+    - mkdir -p /kaniko/.docker
+    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"auth\":\"$(echo -n ${CI_REGISTRY_USER}:${CI_REGISTRY_PASSWORD} | base64 | tr -d '\n')\"},\"$harbor_registry\":{\"auth\":\"$HARBOR_ROBOT_TOKEN64\"}}}" > /kaniko/.docker/config.json
+    - /kaniko/executor
+      --context $CI_PROJECT_DIR
+      --dockerfile $CI_PROJECT_DIR/Dockerfile
+      --build-arg build_date=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
+      --build-arg vcs_ref=${CI_COMMIT_SHORT_SHA}
+      --build-arg version=${CI_COMMIT_SHORT_SHA}
+      --destination $CI_REGISTRY_IMAGE/repdav:$CI_COMMIT_SHORT_SHA
+      --destination $harbor_registry/$harbor_repo/repdav:$CI_COMMIT_SHORT_SHA
+  rules:
+    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH