move ci templates from kubernetes-cluster/templates/ci

image_variables.gitlab-ci.yml

+variables:
+  IMAGE_SERVER: registry.420joos.dev
+
+  DOCKER_BUILDX_IMAGE: $IMAGE_SERVER/docker-buildx:1.1

images.gitlab-ci.yml

+include:
+- local: image_variables.gitlab-ci.yml
+
+stages:
+- build
+
+variables:
+  DOCKER_BUILDX_CONTEXT_NAME: autobuilder
+  DOCKER_BUILDX_PLATFORMS: linux/amd64,linux/arm64
+  DOCKER_BUILDX_CREATE_CMD:  docker buildx create --name $DOCKER_BUILDX_CONTEXT_NAME --platform $DOCKER_BUILDX_PLATFORMS --driver docker-container --bootstrap # --config testbuilder.toml only needed when using http image registry
+  DOCKER_BUILDX_DELETE_CMD: docker buildx rm $DOCKER_BUILDX_CONTEXT_NAME
+  DOCKER_PREPARE_CMD: docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
+  DOCKER_LOGIN_CMD: docker login $IMAGE_SERVER --username $DOCKER_USERNAME --password $DOCKER_PASSWORD
+  DOCKER_LOGOUT_CMD: docker logout $IMAGE_SERVER
+
+# Required vars:
+## IMAGE_PATH
+## IMAGE_NAME
+# Optional vars:
+.build_image_job_template:
+  stage: build
+  tags:
+    - docker
+  retry: 2
+  image: $DOCKER_BUILDX_IMAGE
+  allow_failure: false
+  variables:
+    IMAGE_PATH: "./"
+  script:
+    - $DOCKER_LOGIN_CMD
+    - $DOCKER_PREPARE_CMD
+    - $DOCKER_BUILDX_CREATE_CMD
+    - docker buildx build $IMAGE_PATH --tag $IMAGE_NAME --platform $DOCKER_BUILDX_PLATFORMS --builder $DOCKER_BUILDX_CONTEXT_NAME --push --build-arg IMAGE_SERVER="$IMAGE_SERVER"
+    - $DOCKER_BUILDX_DELETE_CMD
+    - $DOCKER_LOGOUT_CMD