feat(tmux): add server death watchdog daemon and multi-socket approver enhancements

tests/test_tmux_server_watchdog.py

@@ -0,0 +1,112 @@
+#!/usr/bin/env python3
+"""test_tmux_server_watchdog.py — Death-capture transition logic.
+
+Covers: steady state is quiet, pid change yields restart, alive->dead
+yields a death bundle, dead->alive yields started, corrupt state file
+is tolerated.
+"""
+
+import json
+import sys
+import unittest
+from pathlib import Path
+from unittest import mock
+
+REPO_ROOT = Path("/home/super/Projects/NetVM")
+BIN_DIR = REPO_ROOT / "bin"
+sys.path.insert(0, str(BIN_DIR))
+
+import tmux_server_watchdog as w
+
+
+class TestEvaluate(unittest.TestCase):
+    def test_steady_alive_is_quiet(self):
+        prev = {"/s": {"pid": 100, "since": "t"}}
+        new, events = w.evaluate(prev, {"/s": 100})
+        self.assertEqual(events, [])
+        self.assertEqual(new["/s"]["pid"], 100)
+
+    def test_pid_change_is_restart(self):
+        prev = {"/s": {"pid": 100, "since": "t"}}
+        new, events = w.evaluate(prev, {"/s": 200})
+        self.assertEqual(len(events), 1)
+        self.assertEqual(events[0]["type"], "restart")
+        self.assertEqual(events[0]["old_pid"], 100)
+
+    def test_alive_to_dead_is_death(self):
+        prev = {"/s": {"pid": 100, "since": "t"}}
+        new, events = w.evaluate(prev, {"/s": None})
+        self.assertEqual(len(events), 1)
+        self.assertEqual(events[0]["type"], "death")
+        self.assertIsNone(new["/s"]["pid"])
+
+    def test_dead_stays_dead_is_quiet(self):
+        prev = {"/s": {"pid": None, "died": "t", "last_pid": 100}}
+        _, events = w.evaluate(prev, {"/s": None})
+        self.assertEqual(events, [])
+
+    def test_dead_to_alive_is_started(self):
+        prev = {"/s": {"pid": None, "died": "t", "last_pid": 100}}
+        _, events = w.evaluate(prev, {"/s": 300})
+        self.assertEqual(len(events), 1)
+        self.assertEqual(events[0]["type"], "started")
+
+    def test_unknown_socket_first_seen_is_started(self):
+        _, events = w.evaluate({}, {"/s": 300})
+        self.assertEqual(events[0]["type"], "started")
+
+
+class TestCheck(unittest.TestCase):
+    def _iso(self, td):
+        state = str(td / "servers.json")
+        log = str(td / "deaths.jsonl")
+        p1 = mock.patch.object(w, "STATE_FILE", state)
+        p2 = mock.patch.object(w, "DEATH_LOG", log)
+        return p1, p2, state, log
+
+    def test_death_writes_bundle(self):
+        import tempfile
+        with tempfile.TemporaryDirectory() as td:
+            td = Path(td)
+            p1, p2, state, log = self._iso(td)
+            with open(state, "w") as f:
+                json.dump({"/s": {"pid": 100, "since": "t"}}, f)
+            with p1, p2, \
+                 mock.patch.object(w, "probe", return_value=None), \
+                 mock.patch.object(w, "collect_forensics",
+                                   return_value={"ts": "t", "socket": "/s",
+                                                 "last_pid": 100}):
+                res = w.check(sockets=["/s"])
+            self.assertEqual(res["events"][0]["type"], "death")
+            bundle = json.loads(open(log).read().strip())
+            self.assertEqual(bundle["event"], "death")
+            self.assertEqual(bundle["last_pid"], 100)
+            self.assertIsNone(json.load(open(state))["/s"]["pid"])
+
+    def test_dry_run_writes_nothing(self):
+        import tempfile
+        with tempfile.TemporaryDirectory() as td:
+            td = Path(td)
+            p1, p2, state, log = self._iso(td)
+            with p1, p2, \
+                 mock.patch.object(w, "probe", return_value=100):
+                res = w.check(sockets=["/s"], dry_run=True)
+            self.assertEqual(res["events"][0]["type"], "started")
+            self.assertFalse(Path(state).exists())
+            self.assertFalse(Path(log).exists())
+
+    def test_corrupt_state_tolerated(self):
+        import tempfile
+        with tempfile.TemporaryDirectory() as td:
+            td = Path(td)
+            p1, p2, state, _ = self._iso(td)
+            with open(state, "w") as f:
+                f.write("{{{nope")
+            with p1, p2, \
+                 mock.patch.object(w, "probe", return_value=100):
+                res = w.check(sockets=["/s"])
+            self.assertEqual(res["events"][0]["type"], "started")
+
+
+if __name__ == "__main__":
+    unittest.main()