docker-build.yml

name: Reusable – Docker build and push

on:
  workflow_call:
    inputs:
      image_name:
        description: "Full image name without registry prefix (e.g. owner/repo-ui)"
        required: true
        type: string
      context:
        description: "Docker build context path"
        required: true
        type: string
      version:
        description: "Image tag / version to apply"
        required: true
        type: string
      registry:
        description: "Container registry hostname"
        required: false
        type: string
        default: ghcr.io
      push:
        description: "Whether to push and sign the image"
        required: false
        type: boolean
        default: false
    secrets:
      registry_token:
        required: true

jobs:
  build:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
      id-token: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Install cosign
        if: ${{ inputs.push }}
        uses: sigstore/cosign-installer@59acb6260d9c0ba8f4a2f9d9b48431a222b68e20 # v3.5.0
        with:
          cosign-release: 'v2.2.4'

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@f95db51fddba0c2d1ec667646a06c2ce06100226 # v3.0.0

      - name: Log into registry ${{ inputs.registry }}
        if: ${{ inputs.push }}
        uses: docker/login-action@343f7c4344506bcbf9b4de18042ae17996df046d # v3.0.0
        with:
          registry: ${{ inputs.registry }}
          username: ${{ github.actor }}
          password: ${{ secrets.registry_token }}

      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@96383f45573cb7f253c731d3b3ab81c87ef81934 # v5.0.0
        with:
          images: ${{ inputs.registry }}/${{ inputs.image_name }}
          tags: ${{ inputs.version }}

      - name: Build and push Docker image
        id: build-and-push
        uses: docker/build-push-action@0565240e2d4ab88bba5387d719585280857ece09 # v5.0.0
        with:
          context: ${{ inputs.context }}
          push: ${{ inputs.push }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      - name: Sign the published Docker image
        if: ${{ inputs.push }}
        env:
          TAGS: ${{ steps.meta.outputs.tags }}
          DIGEST: ${{ steps.build-and-push.outputs.digest }}
        run: echo "${TAGS}" | xargs -I {} cosign sign --yes {}@${DIGEST}