name: Reusable Image Security Checks

on:
  workflow_call:
    inputs:
      image_name:
        required: true
        type: string
      image_tag:
        type: string
        default: "latest"
      scan_severity:
        type: string
        default: "HIGH,CRITICAL"
    secrets:
      REGISTRY_USERNAME: { required: true }
      REGISTRY_PASSWORD: { required: true }
      DOCKER_REGISTRY: { required: true }

jobs:
  scan:
    runs-on: docker
    container:
      image: gitea.tech-buddy.at/bitbuddydev/gitea_runner_python314:dev-bda315b82bb23d83065b77d91fedf0e20d9accf1
      credentials:
        username: ${{ secrets.REGISTRY_USERNAME }}
        password: ${{ secrets.REGISTRY_PASSWORD }}

    steps:
      - name: Docker Login
        run: |
          echo "${{ secrets.REGISTRY_PASSWORD }}" | docker login "${{ secrets.DOCKER_REGISTRY }}" -u "${{ secrets.REGISTRY_USERNAME }}" --password-stdin

      - name: Pull Image
        shell: bash
        run: |
          set -euo pipefail
          FULL_IMAGE="${{ secrets.DOCKER_REGISTRY }}/${{ inputs.image_name }}:${{ inputs.image_tag }}"
          echo "=== Pulling ${FULL_IMAGE} ==="
          docker pull "${FULL_IMAGE}"

      - name: Image Vulnerability Scan
        shell: bash
        run: |
          set -euo pipefail

          # Fallback for runner images without Trivy baked in. Pinned version +
          # checksum, never "latest": Trivy releases were compromised in the
          # March 2026 supply-chain incident (malicious v0.69.4). Keep in sync
          # with the ARGs in the PipelineImage Dockerfiles.
          TRIVY_VERSION=0.71.0
          TRIVY_SHA256=30a3d22b23f88c233f1658f562fb477cae3b3e8b4761109d515b7698daf85814
          if ! command -v trivy >/dev/null 2>&1; then
            echo "=== Trivy not in runner image, installing v${TRIVY_VERSION} ==="
            curl -sSfLO "https://github.com/aquasecurity/trivy/releases/download/v${TRIVY_VERSION}/trivy_${TRIVY_VERSION}_Linux-64bit.tar.gz"
            echo "${TRIVY_SHA256}  trivy_${TRIVY_VERSION}_Linux-64bit.tar.gz" | sha256sum -c -
            tar -xzf "trivy_${TRIVY_VERSION}_Linux-64bit.tar.gz" -C /usr/local/bin trivy
            rm "trivy_${TRIVY_VERSION}_Linux-64bit.tar.gz"
          fi
          trivy --version

          FULL_IMAGE="${{ secrets.DOCKER_REGISTRY }}/${{ inputs.image_name }}:${{ inputs.image_tag }}"

          echo "=== Scanning ${FULL_IMAGE} (fail on fixable ${{ inputs.scan_severity }}) ==="
          trivy image \
            --exit-code 1 \
            --severity "${{ inputs.scan_severity }}" \
            --ignore-unfixed \
            --scanners vuln,secret \
            "${FULL_IMAGE}"