Merge pull request #3 from synyx/ci-release #1

	name: release

	on:
	push:
	branches:
	- main
	tags:
	- v*
	env:
	IMAGE_NAME: pandocweb
	jobs:
	push:
	runs-on: ubuntu-latest
	permissions:
	packages: write
	contents: read
	steps:
	- uses: actions/checkout@v3
	- name: Build image
	run: docker build . --file Dockerfile --tag $IMAGE_NAME --label "runnumber=${GITHUB_RUN_ID}"
	- name: Log in to registry
	run: echo "${{ secrets.GITHUB_TOKEN }}" \| docker login ghcr.io -u $ --password-stdin
	- name: Push image
	run: \|
	IMAGE_ID=ghcr.io/${{ github.repository_owner }}/$IMAGE_NAME

	# This changes all uppercase characters to lowercase.
	IMAGE_ID=$(echo $IMAGE_ID \| tr '[A-Z]' '[a-z]')
	# This strips the git ref prefix from the version.
	VERSION=$(echo "${{ github.ref }}" \| sed -e 's,./$.$,\1,')
	# This strips the "v" prefix from the tag name.
	[[ "${{ github.ref }}" == "refs/tags/"* ]] && VERSION=$(echo $VERSION \| sed -e 's/^v//')
	# This uses the Docker `latest` tag convention.
	[ "$VERSION" == "main" ] && VERSION=latest
	echo IMAGE_ID=$IMAGE_ID
	echo VERSION=$VERSION
	docker tag $IMAGE_NAME $IMAGE_ID:$VERSION
	docker push $IMAGE_ID:$VERSION

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