name: Kube-bench CIS scan

on:
  pull_request:
  push:
    branches: [main]

permissions:
  contents: read

jobs:
  kube-bench:
    name: Scan ephemeral K3s cluster
    runs-on: ubuntu-latest
    timeout-minutes: 15

    steps:
      - name: Check out repository
        uses: actions/checkout@v4

      - name: Install k3d
        run: curl -sfL https://raw.githubusercontent.com/k3d-io/k3d/main/install.sh | bash

      - name: Install kubectl
        shell: bash
        run: |
          set -euo pipefail
          kubectl_version=v1.35.5
          temp_dir="$(mktemp -d)"
          trap 'rm -rf "$temp_dir"' EXIT
          curl --fail --location --retry 3 \
            --output "$temp_dir/kubectl" \
            "https://dl.k8s.io/release/${kubectl_version}/bin/linux/amd64/kubectl"
          curl --fail --location --retry 3 \
            --output "$temp_dir/kubectl.sha256" \
            "https://dl.k8s.io/release/${kubectl_version}/bin/linux/amd64/kubectl.sha256"
          printf '%s  %s\n' "$(cat "$temp_dir/kubectl.sha256")" "$temp_dir/kubectl" | sha256sum --check --strict -
          install -m 0755 "$temp_dir/kubectl" /usr/local/bin/kubectl
          kubectl version --client

      - name: Create ephemeral K3s cluster
        run: |
          k3d cluster delete security-baseline-ci >/dev/null 2>&1 || true
          k3d cluster create --config ci/k3d-ci-cluster-config.yaml
          mkdir -p "$HOME/.kube"
          k3d kubeconfig get security-baseline-ci > "$HOME/.kube/config"
          api_host=127.0.0.1
          if getent hosts host.docker.internal >/dev/null 2>&1; then
            api_host=host.docker.internal
          elif command -v docker >/dev/null 2>&1; then
            docker_gateway="$(docker network inspect bridge --format '{{(index .IPAM.Config 0).Gateway}}' 2>/dev/null || true)"
            if [[ -n "$docker_gateway" ]]; then
              api_host="$docker_gateway"
            fi
          fi
          if [[ "$api_host" == 127.0.0.1 && -r /proc/net/route ]]; then
            gateway_hex="$(awk '$2 == "00000000" {print $3; exit}' /proc/net/route)"
            if [[ "$gateway_hex" =~ ^[0-9A-Fa-f]{8}$ ]]; then
              api_host="$((16#${gateway_hex:6:2})).$((16#${gateway_hex:4:2})).$((16#${gateway_hex:2:2})).$((16#${gateway_hex:0:2}))"
            fi
          fi
          sed -i -E "s#https://0\.0\.0\.0:#https://${api_host}:#" "$HOME/.kube/config"
          kubectl wait --for=condition=Ready nodes --all --timeout=180s
          kubectl get nodes -o wide

      - name: Run kube-bench
        id: scan
        shell: bash
        run: |
          set +e
          mkdir -p artifacts
          kubectl create namespace kube-bench --dry-run=client -o yaml | kubectl apply -f -
          kubectl apply -f ci/kube-bench-k3s-job.yaml
          kubectl wait --for=condition=complete job/kube-bench -n kube-bench --timeout=180s
          job_rc=$?
          kubectl logs -n kube-bench job/kube-bench > artifacts/kube-bench-k3s-cis-1.7.json || true

          if ! jq -e . artifacts/kube-bench-k3s-cis-1.7.json >/dev/null; then
            echo "kube-bench did not produce valid JSON" >&2
            cat artifacts/kube-bench-k3s-cis-1.7.json
            exit 1
          fi

          pass_count=$(jq '[.. | objects | select(has("total_pass")) | .total_pass] | add // 0' artifacts/kube-bench-k3s-cis-1.7.json)
          warn_count=$(jq '[.. | objects | select(has("total_warn")) | .total_warn] | add // 0' artifacts/kube-bench-k3s-cis-1.7.json)
          fail_count=$(jq '[.. | objects | select(has("total_fail")) | .total_fail] | add // 0' artifacts/kube-bench-k3s-cis-1.7.json)

          {
            echo "## kube-bench CIS K3s 1.7"
            echo
            echo "| Result | Count |"
            echo "| --- | ---: |"
            echo "| Pass | ${pass_count} |"
            echo "| Warn | ${warn_count} |"
            echo "| Fail | ${fail_count} |"
            echo
            echo "Findings are reported as an artifact. The disposable K3d baseline is not a merge gate yet."
          } >> "$GITHUB_STEP_SUMMARY"

          exit "$job_rc"

      - name: Upload kube-bench report
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: kube-bench-k3s-cis-1.7
          path: artifacts/kube-bench-k3s-cis-1.7.json
          if-no-files-found: warn

      - name: Delete ephemeral cluster
        if: always()
        run: k3d cluster delete security-baseline-ci