Create and publish a Docker image on release #4

	# loosley based on https://docs.github.com/en/actions/publishing-packages/publishing-docker-images#publishing-images-to-github-packages
	#
	# a push to "/refs/heads/releases/v1" results in a tag of "releases-v1" per https://github.com/docker/metadata-action#usage

	name: Create and publish a Docker image on release

	on:
	push:
	branches: ['release']
	workflow_dispatch:

	env:
	REGISTRY: us-docker.pkg.dev/uwit-mci-iam/containers
	OWNER_IMAGE: ${{ github.repository }}

	jobs:
	build-and-push-image-to-gar:
	runs-on: ubuntu-latest
	permissions:
	contents: read
	packages: write

	steps:
	- name: Checkout repo
	uses: actions/checkout@v4

	- name: Compute repository name
	id: image_name
	run: \|
	# GH=uwit-iam/nginx-saml-proxy; echo ${GH#*/} returns "nginx-saml-proxy"
	echo "IMAGE_NAME=${OWNER_IMAGE#*/}" >> $GITHUB_OUTPUT

	- name: Auth to Cloud
	uses: 'uwit-iam/action-auth-artifact-registry@main'
	with:
	credentials: "${{ secrets.MCI_GCLOUD_AUTH_JSON }}"

	- name: Extract metadata (tags + labels) for Docker
	id: meta
	# should this be pinned?
	# https://github.com/docker/metadata-action
	uses: docker/[email protected]
	with:
	images: ${{ env.REGISTRY }}/${{ steps.image_name.outputs.IMAGE_NAME }}

	- name: Build and push Docker image
	# should this be pinned?
	# https://github.com/docker/build-push-action
	uses: docker/[email protected]
	with:
	context: .
	push: true
	tags: ${{ steps.meta.outputs.tags }}
	labels: ${{ steps.meta.output.labels }}

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