# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0

name: Trivy Changes

on:
  pull_request:
  merge_group:
    types: [checks_requested]
  workflow_dispatch:
    inputs:
      base_sha:
        description: Base commit SHA to compare
        required: true
        type: string
      head_sha:
        description: Candidate commit SHA to compare
        required: true
        type: string

permissions:
  contents: read

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

jobs:
  changes:
    name: Detect deployment configuration changes
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: read
    outputs:
      should_run: ${{ steps.default.outputs.should_run || steps.changed.outputs.any_modified }}
      base_sha: ${{ steps.comparison.outputs.base_sha }}
    steps:
      - id: default
        if: github.event_name != 'pull_request'
        run: echo "should_run=true" >> "$GITHUB_OUTPUT"

      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
        if: github.event_name == 'pull_request'
        with:
          ref: ${{ github.sha }}
          # Include both parents of the exact PR merge commit, even on reruns.
          fetch-depth: 2
          persist-credentials: false

      - name: Resolve PR baseline
        id: comparison
        if: github.event_name == 'pull_request'
        run: |
          git rev-parse --verify HEAD^2 >/dev/null
          base_sha=$(git rev-parse --verify HEAD^1)
          echo "base_sha=$base_sha" >> "$GITHUB_OUTPUT"
          echo "Trivy comparison: $base_sha -> $(git rev-parse HEAD)"

      - id: changed
        if: github.event_name == 'pull_request'
        uses: tj-actions/changed-files@aa08304bd477b800d468db44fe10f6c61f7f7b11 # v42.1.0
        with:
          base_sha: ${{ steps.comparison.outputs.base_sha }}
          sha: ${{ github.sha }}
          output_renamed_files_as_deleted_and_added: true
          # `any_modified` covers deletions, which `any_changed` omits, and a
          # failed diff has to fail the job: both otherwise report no relevant
          # change, and removing the scanner or a value fixture would skip the
          # scan behind a green status.
          fail_on_initial_diff_error: true
          files: |
            deploy/docker/**
            deploy/helm/**
            deploy/kube/**
            .trivyignore.yaml
            flake.nix
            flake.lock
            tasks/scripts/trivy-scan.sh
            tasks/scripts/trivy-scan-test.sh
            tasks/scripts/trivy-config-report.jq
            .github/workflows/trivy-scan.yml
            .github/workflows/trivy-changes.yml

  scan:
    name: Scan changed deployment configuration
    needs: changes
    if: needs.changes.outputs.should_run == 'true'
    runs-on: ubuntu-latest
    timeout-minutes: 30
    env:
      BASE_REF: ${{ needs.changes.outputs.base_sha || github.event.merge_group.base_sha || inputs.base_sha }}
      HEAD_REF: ${{ inputs.head_sha || github.sha }}
    defaults:
      run:
        shell: nix develop --command bash -euo pipefail {0}
    steps:
      - name: Check out candidate
        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
        with:
          ref: ${{ env.HEAD_REF }}
          persist-credentials: false

      - name: Check out baseline
        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
        with:
          ref: ${{ env.BASE_REF }}
          path: .trivy-base
          persist-credentials: false

      - name: Set up Nix
        uses: ./.github/actions/setup-nix

      - name: Test report comparison
        run: tasks/scripts/trivy-scan-test.sh

      - name: Validate candidate ignore policy
        run: tasks/scripts/trivy-scan.sh validate-ignore

      # Ignore-policy changes take effect only after merge. Applying the
      # baseline policy to both scans prevents a candidate from exempting a new
      # finding in the same change that introduces it.
      - name: Prepare baseline ignore policy
        run: |
          if [ -f .trivy-base/.trivyignore.yaml ]; then
            cp .trivy-base/.trivyignore.yaml "$RUNNER_TEMP/trivy-baseline-ignore.yaml"
          else
            printf 'misconfigurations: []\n' >"$RUNNER_TEMP/trivy-baseline-ignore.yaml"
          fi

      - name: Scan baseline
        env:
          TRIVY_SOURCE_ROOT: ${{ github.workspace }}/.trivy-base
          TRIVY_IGNORE_FILE: ${{ runner.temp }}/trivy-baseline-ignore.yaml
          TRIVY_REPORT_DIR: ${{ runner.temp }}/trivy-base
        run: |
          mkdir -p "$TRIVY_REPORT_DIR"
          "$GITHUB_WORKSPACE/tasks/scripts/trivy-scan.sh" config

      - name: Scan candidate
        env:
          TRIVY_IGNORE_FILE: ${{ runner.temp }}/trivy-baseline-ignore.yaml
          TRIVY_REPORT_DIR: ${{ runner.temp }}/trivy-head
        run: |
          mkdir -p "$TRIVY_REPORT_DIR"
          tasks/scripts/trivy-scan.sh config

      - name: Reject new high or critical findings
        run: |
          tasks/scripts/trivy-scan.sh gate-config-diff \
            "$RUNNER_TEMP/trivy-base" "$RUNNER_TEMP/trivy-head"

      - name: Upload reports
        if: always()
        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
        with:
          name: trivy-changes-${{ github.run_id }}
          path: |
            ${{ runner.temp }}/trivy-base
            ${{ runner.temp }}/trivy-head
          if-no-files-found: ignore
          retention-days: 14

  result:
    name: OpenShell / Trivy Changes
    needs: [changes, scan]
    if: always()
    runs-on: ubuntu-latest
    steps:
      - name: Check scan result
        env:
          CHANGES_RESULT: ${{ needs.changes.result }}
          SHOULD_RUN: ${{ needs.changes.outputs.should_run }}
          SCAN_RESULT: ${{ needs.scan.result }}
        run: |
          set -euo pipefail
          if [ "$CHANGES_RESULT" != "success" ]; then
            echo "::error::Change detection concluded $CHANGES_RESULT."
            exit 1
          fi
          if [ "$SHOULD_RUN" = "true" ] && [ "$SCAN_RESULT" != "success" ]; then
            echo "::error::Trivy scan concluded $SCAN_RESULT."
            exit 1
          fi
          if [ "$SHOULD_RUN" != "true" ]; then
            echo "No Helm or Dockerfile changes to scan."
          fi