Add .gitlab-ci.yml

.gitlab-ci.yml

+# This file is a template, and might need editing before it works on your project.
+# Official docker image.
+image: docker:git
+
+build:
+  stage: build
+  tags: 
+    - shared
+  script:
+    - export IMAGE_TAG=$(echo -en $CI_BUILD_REF_NAME | tr -c '[:alnum:]_.-' '-')
+    - export TAG=$(if [ "${IMAGE_TAG}" == "master" ]; then echo "latest"; else echo ${IMAGE_TAG}; fi)
+    - export COMMIT=$(git rev-parse --short --verify HEAD)
+    - docker login -u "gitlab-ci-token" -p "$CI_BUILD_TOKEN" $CI_REGISTRY
+    - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
+    - docker build --pull -t "$CI_REGISTRY_IMAGE:${COMMIT}" .
+    - docker tag "$CI_REGISTRY_IMAGE:${COMMIT}" "$CI_REGISTRY_IMAGE:${TAG}"
+    - docker push "$CI_REGISTRY_IMAGE"