Initial code

.gitlab-ci.yml

+before_script:
+  - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
+
+build-master:
+  stage: build
+  script:
+    - docker build --pull -t $CI_REGISTRY_IMAGE .
+    - docker push $CI_REGISTRY_IMAGE
+  only:
+    - master

Dockerfile

+FROM registry.lakedrops.com/docker/gitlab-drupal-ci
+
+LABEL com.example.vendor="LakeDrops" \
+      maintainer="juergen.haas@lakedrops.com" \
+      version="1.0.0" \
+      description="Drupal development environment from LakeDrops."
+
+ENV LAKEDROPS_DEV_ENV 1