Add dockerfile and ci

Add image to registry with openshift-cli and gettext

.gitlab-ci.yml

+stages:
+  - build
+
+.build:
+  stage: build
+  image: 
+      name: gitlab-registry.cern.ch/ci-tools/docker-image-builder
+      entrypoint: [""]
+  script:
+      - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
+      - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/Dockerfile --destination $IMAGE_DESTINATION
+      - echo "Image pushed successfully to ${IMAGE_DESTINATION}"
+
+
+#####################################################
+################### Merge Requests ##################
+
+build_mr:
+  extends: .build
+  variables:
+    IMAGE_DESTINATION: ${CI_REGISTRY_IMAGE}/openshift-cli:${CI_COMMIT_REF_SLUG}
+  rules:
+    - if:  $CI_MERGE_REQUEST_ID
+      when: manual
+      allow_failure: true
+    - when: never
+
+######################################################
+#################### Master branch ###################
+
+build_master:
+  extends: .build
+  variables:
+    IMAGE_DESTINATION: ${CI_REGISTRY_IMAGE}/openshift-cli:latest
+  rules:
+    - if: $CI_COMMIT_BRANCH == 'master'
+    - when: never