Monitor Sage stable image updates #527

	name: Monitor Sage stable image updates

	on:
	schedule:
	- cron: '0 0 * * *' # Run once every day
	workflow_dispatch:

	jobs:
	build:
	runs-on: ubuntu-latest

	env:
	SAGE_DOCKER_LATEST: "ghcr.io/sagemath/sage/sage-ubuntu-focal-standard-with-targets:latest"

	steps:
	- name: Checkout code
	uses: actions/checkout@v3
	with:
	ref: master

	- name: Get SageMath version
	run: \|
	SAGE_VERSION=$(docker run --rm $SAGE_DOCKER_LATEST /sage/sage --version \| grep -oP 'SageMath version \K[0-9.]+(?:beta\d+)?')
	echo "SAGE_VERSION=${SAGE_VERSION}" >> $GITHUB_ENV

	- name: Replace Docker image tag
	run: \|
	SAGE_IMAGE_NAME="${SAGE_DOCKER_LATEST%:latest}"
	NEW_IMAGE_NAME="${SAGE_IMAGE_NAME}:${SAGE_VERSION}"
	echo "SAGE_DOCKER_UPDATED=${NEW_IMAGE_NAME}" >> $GITHUB_ENV

	- name: Update Dockerfile
	run: \|
	SAGE_DOCKER_UPDATED_ESCAPED=$(echo "${SAGE_DOCKER_UPDATED}" \| sed 's/\//\\\//g')
	sed -i "s/FROM \S*/FROM $SAGE_DOCKER_UPDATED_ESCAPED/g" Dockerfile
	sed -i "s/FROM \S*/FROM $SAGE_DOCKER_UPDATED_ESCAPED/g" README.rst

	- name: Commit changes
	run: \|
	git config --global user.email alice@wonderland
	git config --global user.name Alice
	git commit -a --amend -m "Update Dockerfile for Sage ${SAGE_VERSION}"
	git push -f origin master

	- name: Have Binder build
	timeout-minutes: 10
	continue-on-error: true
	run: \|
	curl -L https://mybinder.org/build/gh/sagemath/sage-binder-env/master

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