build-and-attest.yml

name: Build and Attest Container

on:
  push:
    tags:
      - 'v*'
  workflow_dispatch:
    inputs:
      version:
        description: 'Version to build (e.g., 0.1.0)'
        required: true
        type: string

permissions:
  contents: write
  packages: write
  id-token: write
  attestations: write
  actions: read

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}
  VERSION: ${{ github.event.inputs.version || github.ref_name }}

jobs:
  build-and-scan:
    runs-on: ubuntu-latest
    outputs:
      digest: ${{ steps.push.outputs.digest }}
      image: ${{ steps.meta.outputs.tags }}

    steps:
      - uses: actions/checkout@v6

      - name: Set up Python
        uses: actions/setup-python@v6
        with:
          python-version: '3.11'

      - name: Embed version
        run: |
          VERSION="${{ env.VERSION }}"
          VERSION="${VERSION#v}"
          echo "__version__ = \"${VERSION}\"" > _version.py

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

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

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v6
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=sha,prefix=
            type=raw,value=latest,enable={{is_default_branch}}

      - name: Build container image (local)
        id: build
        uses: docker/build-push-action@v6
        with:
          context: .
          load: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      - name: Scan for critical vulnerabilities
        run: |
          # Install grype
          curl -sSfL https://raw.githubusercontent.com/anchore/grype/main/install.sh | sh -s -- -b /usr/local/bin

          # Get the first tag for scanning
          IMAGE_TAG=$(echo "${{ steps.meta.outputs.tags }}" | head -n1)

          echo "=== Scanning image for vulnerabilities ==="
          grype "$IMAGE_TAG" --output table

          echo "=== Checking for critical vulnerabilities ==="
          if ! grype "$IMAGE_TAG" --fail-on critical; then
            echo "::error::Critical vulnerabilities detected! Image will NOT be pushed."
            exit 1
          fi

          echo "No critical vulnerabilities found. Proceeding with push."

      - name: Push container image
        id: push
        uses: docker/build-push-action@v6
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max
          provenance: true
          sbom: true

      - name: Output image digest
        run: |
          echo "Image digest: ${{ steps.push.outputs.digest }}"
          echo "${{ steps.push.outputs.digest }}" > image-digest.txt

      - name: Upload digest artifact
        uses: actions/upload-artifact@v6
        with:
          name: image-digest
          path: image-digest.txt
          retention-days: 90

  sign-and-attest:
    needs: build-and-scan
    runs-on: ubuntu-latest
    permissions:
      packages: write
      id-token: write
      attestations: write

    steps:
      - uses: actions/checkout@v6

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

      - name: Install cosign
        uses: sigstore/cosign-installer@v3

      - name: Install syft for SBOM generation
        uses: anchore/sbom-action/download-syft@v0

      - name: Sign container image with Sigstore
        env:
          DIGEST: ${{ needs.build-and-scan.outputs.digest }}
        run: |
          IMAGE="${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${DIGEST}"
          echo "Signing image: $IMAGE"

          cosign sign --yes "$IMAGE"

          echo "Image signed successfully"

      - name: Generate SBOM for container image
        env:
          DIGEST: ${{ needs.build-and-scan.outputs.digest }}
        run: |
          IMAGE="${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${DIGEST}"

          # Generate SBOM in CycloneDX format
          syft "$IMAGE" -o cyclonedx-json > sbom.cdx.json

          echo "SBOM generated: sbom.cdx.json"

      - name: Attest SBOM to container image
        env:
          DIGEST: ${{ needs.build-and-scan.outputs.digest }}
        run: |
          IMAGE="${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${DIGEST}"

          cosign attest --yes \
            --predicate sbom.cdx.json \
            --type cyclonedx \
            "$IMAGE"

          echo "SBOM attestation attached to image"

      - name: Upload SBOM artifact
        uses: actions/upload-artifact@v6
        with:
          name: container-sbom
          path: sbom.cdx.json
          retention-days: 90

  # SLSA Level 3 provenance generation using official SLSA generator
  # This runs in an isolated, hardened environment for stronger security guarantees
  provenance:
    needs: build-and-scan
    permissions:
      actions: read
      id-token: write
      packages: write
    uses: slsa-framework/slsa-github-generator/.github/workflows/generator_container_slsa3.yml@v2.1.0
    with:
      image: ghcr.io/${{ github.repository }}
      digest: ${{ needs.build-and-scan.outputs.digest }}
      registry-username: ${{ github.actor }}
    secrets:
      registry-password: ${{ secrets.GITHUB_TOKEN }}

  release:
    needs: [build-and-scan, sign-and-attest, provenance]
    runs-on: ubuntu-latest
    if: startsWith(github.ref, 'refs/tags/')
    permissions:
      contents: write

    steps:
      - uses: actions/checkout@v6

      - name: Download artifacts
        uses: actions/download-artifact@v6
        with:
          name: image-digest
          path: .

      - name: Download SBOM
        uses: actions/download-artifact@v6
        with:
          name: container-sbom
          path: .

      - name: Create GitHub Release
        uses: softprops/action-gh-release@v2
        with:
          files: |
            image-digest.txt
            sbom.cdx.json
            deploy/deploy.sh
            deploy/verify.sh
          generate_release_notes: true
          body: |
            ## Container Image

            ```
            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${{ needs.build-and-scan.outputs.digest }}
            ```

            ## Quick Deploy

            ```bash
            # Download deploy script
            curl -fsSL -o deploy.sh https://github.com/${{ github.repository }}/releases/latest/download/deploy.sh
            chmod +x deploy.sh

            # Deploy (requires Docker or Podman)
            sudo ./deploy.sh ${{ github.ref_name }}
            ```

            ## Verification

            ### Verify image signature
            ```bash
            cosign verify ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${{ needs.build-and-scan.outputs.digest }} \
              --certificate-identity-regexp ".*" \
              --certificate-oidc-issuer "https://token.actions.githubusercontent.com"
            ```

            ### Verify SBOM attestation
            ```bash
            cosign verify-attestation ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${{ needs.build-and-scan.outputs.digest }} \
              --type cyclonedx \
              --certificate-identity-regexp ".*" \
              --certificate-oidc-issuer "https://token.actions.githubusercontent.com"
            ```

            ### Verify SLSA provenance (Level 3)
            ```bash
            slsa-verifier verify-image ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${{ needs.build-and-scan.outputs.digest }} \
              --source-uri github.com/${{ github.repository }}
            ```

            ### Verify runtime integrity
            After deployment, the `image_digest` from the API should match:
            ```bash
            curl -s http://localhost:8000/ping | jq -r '.image_digest'
            # Should return: ${{ needs.build-and-scan.outputs.digest }}
            ```