Docker #771

	name: Docker

	on:
	push:
	# Publish `master` as Docker `latest` image.
	branches:
	- master

	# Publish `v1.2.3` tags as releases.
	tags:
	- v*

	# Automatically rebuild latest tag
	schedule:
	- cron: "7 23 * * *"

	jobs:
	# Push image to GitHub Packages.
	# See also https://docs.docker.com/docker-hub/builds/
	push:
	runs-on: ubuntu-latest
	strategy:
	matrix:
	image: [rails, mailcatcher]

	steps:
	- uses: actions/checkout@v2

	- name: Build images
	run: \|
	docker build ./docker/${{ matrix.image }} --tag ${{ matrix.image }}

	- name: Log into registry
	run: echo "${{ secrets.GITHUB_TOKEN }}" \| docker login ghcr.io -u ${{ github.actor }} --password-stdin

	- name: Push images
	run: \|
	IMAGE_ID=ghcr.io/${{ github.repository }}/${{ matrix.image }}

	# Change all uppercase to lowercase
	IMAGE_ID=$(echo $IMAGE_ID \| tr '[A-Z]' '[a-z]')

	# Strip git ref prefix from version
	VERSION=$(echo "${{ github.ref }}" \| sed -e 's,./$.$,\1,')

	# Strip "v" prefix from tag name
	[[ "${{ github.ref }}" == "refs/tags/"* ]] && VERSION=$(echo $VERSION \| sed -e 's/^v//')

	# Use Docker `latest` tag convention
	[ "$VERSION" == "master" ] && VERSION=latest

	echo IMAGE_ID=$IMAGE_ID
	echo VERSION=$VERSION

	docker tag ${{ matrix.image }} $IMAGE_ID:$VERSION
	docker push $IMAGE_ID:$VERSION

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