Replace `set-output` with `$GITHUB_OUTPUT` #194

	name: docker

	on:
	push:
	branches:
	pull_request:

	jobs:
	docker:
	runs-on: ubuntu-20.04
	steps:
	- name: Checkout
	uses: actions/checkout@v2

	- name: Set some variables
	id: vars
	run: \|
	short_sha=$(git rev-parse --short HEAD)
	image="jupyter/nbviewer:$short_sha"
	echo "image=$image" >> $GITHUB_OUTPUT
	tags="$image"
	if "${{ github.ref_name }}" == "main" ]]; then
	tags="jupyter/nbviewer:latest $tags"
	fi
	echo "tags=$tags" >> $GITHUB_OUTPUT

	- name: Check outputs
	run: echo ${{ steps.vars.outputs.sha_short }}

	- name: Login to docker hub
	if: github.ref_name == 'main'
	uses: docker/login-action@v1
	with:
	username: ${{ secrets.DOCKER_USERNAME }}
	password: ${{ secrets.DOCKER_PASSWORD }}

	- name: Build
	uses: docker/build-push-action@v2
	with:
	push: false
	load: true
	context: .
	platforms: linux/amd64
	tags: ${{ steps.vars.outputs.tags }}

	- name: Test
	run: \|
	docker run --rm -i ${{ steps.vars.outputs.image }} python3 -c "import nbviewer, pycurl, pylibmc"
	docker run --rm -i ${{ steps.vars.outputs.image }} python3 -m nbviewer --help-all

	- name: Push
	if: github.ref_name == 'main'
	uses: docker/build-push-action@v2
	with:
	context: .
	platforms: linux/amd64
	push: ${{ github.ref_name == 'main' }}
	tags: ${{ steps.vars.outputs.tags }}

Provide feedback