Add gitlab CI template

Using templates provides an easy way to integrate the build into more
pipelines without worrying about updates too much.

.gitlab-ci.yml

-image: quay.io/sheogorath/build-ah-engine
-
-stages:
-  - analyse
-  - build
-  - test
-  - tag
-  - deploy
-
-before_script:
-  - podman login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
+include:
+  local: /gitlab-ci-template.yml
 
 variables:
-  BAE_VERSION: "1.0.0"
-  SI_TOOLS_VERSION: "0.2.0"
-
-build:
-  stage: build
-  script:
-    - podman build --pull --build-arg SI_TOOLS_VERSION -t "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG" .
-    - podman push "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG"
+  CONTAINER_VERSION: "1.0.0"
+  CI_REGISTRY_BUILD_ARG: "--build-arg 0.2.0"
 
-tagging-master:
-  stage: tag
-  script:
-    - podman pull "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG"
-    - si-tagging -l "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG" "$CI_REGISTRY_IMAGE" "${BAE_VERSION}"
-    - si-push "$CI_REGISTRY_IMAGE"
+container-tagging:
   only:
     - master

gitlab-ci-template.yml

+stages:
+  - build
+  - tag
+
+variables:
+  CI_REGISTRY_BUILD_ARGS: ""
+
+container-build:
+  stage: build
+  inherit:
+    default: false
+    variables:
+      - CI_REGISTRY
+      - CI_REGISTRY_USER
+      - CI_REGISTRY_PASSWORD
+      - CI_REGISTRY_IMAGE
+      - CI_REGISTRY_BUILD_ARGS
+  image: quay.io/sheogorath/build-ah-engine:1.0.0
+  before_script:
+    - podman login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
+  script:
+    - podman build --pull $CI_REGISTRY_BUILD_ARGS -t "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG-$CI_COMMIT_SHORT_SHA" .
+    - podman push "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG-$CI_COMMIT_SHORT_SHA"
+
+container-tagging:
+  stage: tag
+  inherit:
+    default: false
+    variables:
+      - CI_REGISTRY
+      - CI_REGISTRY_USER
+      - CI_REGISTRY_PASSWORD
+      - CI_REGISTRY_IMAGE
+      - CI_REGISTRY_IMAGE_VERSION
+  image: quay.io/sheogorath/build-ah-engine:1.0.0
+  before_script:
+    - podman login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
+  script:
+    - podman pull "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG-$CI_COMMIT_SHORT_SHA"
+    - si-tagging -l "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG" "$CI_REGISTRY_IMAGE" "${CI_REGISTRY_IMAGE_VERSION}"
+    - si-push "$CI_REGISTRY_IMAGE"