reusable-build.yml

name: Reusable Build Workflow

on:
  workflow_call:
    inputs:
      image-name:
        required: true
        type: string
        description: "The name of the Docker image"
      push:
        required: false
        type: boolean
        default: false
        description: "Whether to push the image to GHCR"
    outputs:
      image_tag:
        description: "The SHA tag of the built image"
        value: ${{ jobs.build.outputs.image_tag }}

env:
  REGISTRY: ghcr.io

jobs:
  build:
    name: Build & Push Image
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    outputs:
      image_tag: ${{ steps.set-tag.outputs.tag }}

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

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

      - name: Log in to GitHub Container Registry
        if: ${{ inputs.push }}
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract metadata (tags, labels)
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ inputs.image-name }}
          tags: |
            type=raw,value=latest,enable=${{ github.ref == format('refs/heads/{0}', 'main') }}
            type=sha,prefix=,format=short

      - name: Build and push Docker image
        uses: docker/build-push-action@v6
        with:
          context: .
          file: ./Dockerfile
          push: ${{ inputs.push }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max
          # Enables Software Bill of Materials (SBOM) for compliance
          provenance: true
          sbom: true

      - name: Export built SHA tag
        id: set-tag
        run: echo "tag=sha-${GITHUB_SHA::7}" >> $GITHUB_OUTPUT