Add --json output to the check command

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

enodia_sentinel/cli.py

@@ -146,7 +146,7 @@ def _reconcile_list(cfg: Config, store, args) -> int:
     return 1 if any_stale else 0
 
 
-def _cmd_check(cfg: Config) -> int:
+def _cmd_check(cfg: Config, as_json: bool = False) -> int:
     # One-shot: arm everything immediately, force the SUID scan.
     sentinel = Sentinel(cfg)
     sentinel.start_time = 0.0  # past the grace window
@@ -154,10 +154,15 @@ def _cmd_check(cfg: Config) -> int:
     if not sentinel.listener_baseline:
         sentinel.build_baselines()
     alerts = sentinel.sweep(force_suid=True)
+    ordered = sorted(alerts, key=lambda x: -x.severity)
+    if as_json:
+        import json
+        print(json.dumps([a.to_dict() for a in ordered], indent=2))
+        return 0
     if not alerts:
         print("No alerts.")
         return 0
-    for a in sorted(alerts, key=lambda x: -x.severity):
+    for a in ordered:
         print(f"[{a.severity}] {a.signature:<14} {a.detail}")
     return 0
 
@@ -172,7 +177,8 @@ def main(argv: list[str] | None = None) -> int:
     parser.add_argument("-c", "--config", help="path to TOML config")
     sub = parser.add_subparsers(dest="cmd")
     sub.add_parser("run", help="run the daemon loop (default)")
-    sub.add_parser("check", help="run detectors once and print alerts")
+    chk = sub.add_parser("check", help="run detectors once and print alerts")
+    chk.add_argument("--json", action="store_true", help="emit alerts as JSON")
     bl = sub.add_parser(
         "baseline",
         help="rebuild baselines (default), or accept/revoke/list drift")
@@ -259,7 +265,7 @@ def main(argv: list[str] | None = None) -> int:
             return _cmd_baseline(cfg)
         return _cmd_reconcile(cfg, args)
     if args.cmd == "check":
-        return _cmd_check(cfg)
+        return _cmd_check(cfg, args.json)
     if args.cmd == "web":
         from .web import serve
         serve(cfg)

tests/test_check_json.py

@@ -0,0 +1,40 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+"""The `check --json` flag emits a parseable JSON alert array."""
+import io
+import json
+import unittest
+from contextlib import redirect_stdout
+from unittest import mock
+
+from enodia_sentinel import cli
+from enodia_sentinel.alert import Alert, Severity
+from enodia_sentinel.config import Config
+
+
+class _FakeSentinel:
+    def __init__(self, cfg):
+        self.start_time = 1.0
+        self.listener_baseline = {"x"}
+
+    def load_baselines(self):
+        pass
+
+    def build_baselines(self):
+        pass
+
+    def sweep(self, force_suid=False):
+        return [Alert(Severity.HIGH, "rsh", "rsh:1", "reverse shell", sid=1001)]
+
+
+class TestCheckJson(unittest.TestCase):
+    def test_check_json_emits_alert_array(self):
+        cfg = Config()
+        with mock.patch.object(cli, "Sentinel", _FakeSentinel):
+            buf = io.StringIO()
+            with redirect_stdout(buf):
+                rc = cli._cmd_check(cfg, True)
+        self.assertEqual(rc, 0)
+        data = json.loads(buf.getvalue())
+        self.assertEqual(len(data), 1)
+        self.assertEqual(data[0]["signature"], "rsh")
+        self.assertEqual(data[0]["sid"], 1001)