Port original nf-core training #1866

	# Build and push the Docker image for GitHub Codespaces
	# - Only pushes if push or release
	# - Builds without push for PRs to check the Dockerfile

	name: Docker image

	on:
	pull_request: # Build, don't push
	push: { branches: [master] } # Build + push ('latest' tag)
	release: { types: [published] } # Build + push (release tag)
	workflow_dispatch: # Build + push (custom tag)
	inputs:
	tag_name:
	description: "Docker image tag name"
	type: string
	required: true

	jobs:
	build_push:
	runs-on: ubuntu-latest
	permissions:
	contents: read
	packages: write
	steps:
	- name: Set tag variable
	run: \|
	if [[ '${{ github.event_name }}' == 'release' ]]; then
	echo "IMAGE_TAG=${{ github.event.release.tag_name }}" >> $GITHUB_ENV
	elif [[ '${{ github.event_name }}' == 'workflow_dispatch' ]]; then
	echo "IMAGE_TAG=${{ inputs.tag_name }}" >> $GITHUB_ENV
	else
	echo "IMAGE_TAG=latest" >> $GITHUB_ENV
	fi

	- name: Check out the repo
	uses: actions/checkout@v4

	- name: Login to GitHub Container Registry
	uses: docker/login-action@v3
	with:
	registry: ghcr.io
	username: ${{ github.repository_owner }}
	password: ${{ secrets.GITHUB_TOKEN }}

	- name: Set up Docker Buildx
	uses: docker/setup-buildx-action@v3

	- name: Build / push image
	uses: docker/build-push-action@v6
	with:
	file: .devcontainer/Dockerfile
	push: ${{ github.event_name != 'pull_request' }}
	tags: ghcr.io/${{ github.repository }}:${{ env.IMAGE_TAG }}
	cache-from: type=gha
	cache-to: type=gha,mode=max

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