Indentation mistake

.gitlab-ci.yml

-services:
-    - docker:dind
-
 variables:
-    DOCKER_HOST: tcp://docket:2375
+    DOCKER_HOST: tcp://docker:2375
     DOCKER_DRIVER: overlay2
+    CONTAINER_TEST_IMAGE: docker.km3net.de/simulation/km3buu:$CI_COMMIT_REF_SLUG
+    CONTAINER_RELEASE_IMAGE: docker.km3net.de/simulation/km3buu:$CI_COMMIT_TAG
+    CONTAINER_LATEST_IMAGE: docker.km3net.de/simulation/km3buu:latest
+
+stages:
+    - docker
+    - release
 
 docker:
-    image: docker:stable
-    services:
-        - docker:dind
-    stage: docker
-    script:
+   image: docker:stable
+   services:
+     - docker:dind
+   stage: docker
+   script:
+     - docker build --pull -t $CONTAINER_TEST_IMAGE .
+     - docker push $CONTAINER_TEST_IMAGE
+   tags:
+     - docker
+   only:
+     - tags
+
+release-image:
+   image: docker:stable
+   services:
+     - docker:dind
+   stage: release
+   script:
+     - docker pull $CONTAINER_TEST_IMAGE
+     - docker tag $CONTAINER_TEST_IMAGE $CONTAINER_RELEASE_IMAGE
+     - docker tag $CONTAINER_TEST_IMAGE $CONTAINER_LATEST_IMAGE
+     - docker push $CONTAINER_RELEASE_IMAGE
+     - docker push $CONTAINER_LATEST_IMAGE
+   tags:
+     - docker
+   only:
+     - tags