name: Trivy Image Scan

# Builds Dockerfile.cli and Dockerfile.web, then scans the resulting images
# for OS-package and language-package CVEs at MEDIUM+ severity.
# Findings upload to the Security tab; record-only (does not block merges).
#
# Trigger on Dockerfile changes in PRs so base-image/npm-layer remediation can
# be verified before merge without running image scans on every PR.

on:
  pull_request:
    paths:
      - 'Dockerfile.cli'
      - 'Dockerfile.web'
      - 'gitnexus/Dockerfile.test'
      - '.github/workflows/trivy.yml'
  push:
    branches: [main]
  schedule:
    - cron: '0 8 * * 1'
  workflow_dispatch:

permissions:
  contents: read

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: false

jobs:
  scan:
    name: Trivy (${{ matrix.image.name }})
    runs-on: ubuntu-latest
    timeout-minutes: 30
    permissions:
      contents: read
      security-events: write

    strategy:
      fail-fast: false
      matrix:
        image:
          - { dockerfile: Dockerfile.cli, name: gitnexus-cli }
          - { dockerfile: Dockerfile.web, name: gitnexus-web }

    steps:
      - name: Checkout
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false

      - name: Setup Buildx
        uses: docker/setup-buildx-action@37fe631027851001ddb9b187196cc803df7f5f0e # v4.3.0

      - name: Build image (load locally for scan)
        uses: docker/build-push-action@53b7df96c91f9c12dcc8a07bcb9ccacbed38856a # v7.3.0
        with:
          context: .
          file: ${{ matrix.image.dockerfile }}
          load: true
          push: false
          tags: scan-target:${{ matrix.image.name }}

      # aquasecurity/trivy-action versions < 0.35.0 are flagged by
      # GHSA-69fq-xp46-6x23 (briefly compromised supply chain). Pinned to
      # v0.36.0 (post-incident clean release) by commit SHA.
      - name: Run Trivy
        uses: aquasecurity/trivy-action@ed142fd0673e97e23eac54620cfb913e5ce36c25 # v0.36.0
        with:
          image-ref: scan-target:${{ matrix.image.name }}
          format: sarif
          output: trivy-${{ matrix.image.name }}.sarif
          severity: MEDIUM,HIGH,CRITICAL
          # Hides CVEs with no available fix in the base image.
          ignore-unfixed: true
          exit-code: '0'

      - name: Upload to Security tab
        uses: github/codeql-action/upload-sarif@cdf488f595d80d6e07e03d4674febd5ab45fa938 # v4.37.9
        with:
          sarif_file: trivy-${{ matrix.image.name }}.sarif
          category: trivy-${{ matrix.image.name }}