build: automatically cancel old tests/build on new push #53

	name: Docker CI

	on:
	pull_request:
	types: [closed]
	workflow_dispatch:
	inputs:
	ref:
	description: "Git ref to build (branch, tag, or SHA)"
	type: string
	required: false

	permissions:
	contents: read

	jobs:
	resolve-ref:
	name: Resolve Checkout Ref
	runs-on: ubuntu-latest
	outputs:
	ref: ${{ steps.pick.outputs.ref }}
	steps:
	- name: Pick ref
	id: pick
	shell: bash
	run: \|
	set -euo pipefail
	EVENT_NAME="${GITHUB_EVENT_NAME}"
	MERGE_SHA=$(jq -r '.pull_request.merge_commit_sha // empty' "$GITHUB_EVENT_PATH")
	INPUT_REF=$(jq -r '.inputs.ref // empty' "$GITHUB_EVENT_PATH")

	if [[ "$EVENT_NAME" == "pull_request" && -n "$MERGE_SHA" ]]; then
	REF="$MERGE_SHA"
	elif [[ -n "$INPUT_REF" ]]; then
	REF="$INPUT_REF"
	else
	echo "Error: no merge commit or input ref provided" >&2
	exit 1
	fi

	echo "ref=$REF" >> "$GITHUB_OUTPUT"

	build:
	name: Build and Push Images
	needs: resolve-ref
	# Run only when the PR is merged and is NOT a release PR, or manual run.
	if: \|
	github.event_name == 'workflow_dispatch' \|\| (
	github.event_name == 'pull_request' &&
	github.event.pull_request.merged == true &&
	!contains(github.event.pull_request.labels.*.name, 'release')
	)
	strategy:
	matrix:
	image: [etl-api, etl-replicator]
	uses: ./.github/workflows/docker-build.yml
	secrets: inherit
	with:
	image: docker.io/${{ vars.DOCKERHUB_USERNAME }}/${{ matrix.image }}
	context: .
	file: ./${{ matrix.image }}/Dockerfile
	push: true
	tag_with_version: false
	# Build from the resolved ref: merge commit for PRs, or provided ref, fallback to current SHA.
	checkout_ref: ${{ needs.resolve-ref.outputs.ref }}

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