Make worker cleanup threads more robust, handle peers without handsha…

…ke time

README.md

@@ -218,10 +218,10 @@ sudo ip link set vx-welt up
 
 ### MQTT topics
 
-Publishing keys broker->worker: `wireguard/{domain}/{worker}`
-Publishing metrics worker->broker: `wireguard-metrics/{domain}/{worker}/connected_peers`
-Publishing worker status: `wireguard-worker/{worker}/status`
-Publishing worker data: `wireguard-worker/{worker}/{domain}/data`
+- Publishing keys broker->worker: `wireguard/{domain}/{worker}`
+- Publishing metrics worker->broker: `wireguard-metrics/{domain}/{worker}/connected_peers`
+- Publishing worker status: `wireguard-worker/{worker}/status`
+- Publishing worker data: `wireguard-worker/{worker}/{domain}/data`
 
 ## Contact
 

wgkex/worker/app.py

@@ -39,9 +39,14 @@ class InvalidDomain(Error):
 def flush_workers(domain: Text) -> None:
     """Calls peer flush every _CLEANUP_TIME interval."""
     while True:
-        time.sleep(_CLEANUP_TIME)
-        logger.info(f"Running cleanup task for {domain}")
-        logger.info("Cleaned up domains: %s", wg_flush_stale_peers(domain))
+        try:
+            time.sleep(_CLEANUP_TIME)
+            logger.info(f"Running cleanup task for {domain}")
+            logger.info("Cleaned up domains: %s", wg_flush_stale_peers(domain))
+        except Exception as e:
+            # Don't crash the thread when an exception is encountered
+            logger.error(f"Exception during cleanup task for {domain}:")
+            logger.error(e)
 
 
 def clean_up_worker() -> None:
@@ -100,7 +105,7 @@ def check_all_domains_unique(domains, prefixes):
                 stripped_domain = domain.split(prefix)[1]
                 if stripped_domain in unique_domains:
                     logger.error(
-                        "We have a non-unique domain here",
+                        f"Domain {domain} is not unique after stripping the prefix",
                         domain,
                     )
                     return False

wgkex/worker/app_test.py

@@ -1,4 +1,6 @@
 """Unit tests for app.py"""
+import threading
+from time import sleep
 import unittest
 import mock
 
@@ -88,14 +90,28 @@ def test_main_fails_bad_domain(self, connect_mock, config_mock):
             app.main()
         connect_mock.assert_not_called()
 
-    @mock.patch("time.sleep", side_effect=InterruptedError)
+    @mock.patch.object(app, "_CLEANUP_TIME", 0)
     @mock.patch.object(app, "wg_flush_stale_peers")
-    def test_flush_workers(self, flush_mock, sleep_mock):
+    def test_flush_workers_doesnt_throw(self, wg_flush_mock, cleanup_time_mock):
         """Ensure we fail when domains are badly formatted."""
-        flush_mock.return_value = ""
-        # Infinite loop in flush_workers has no exit value, so test will generate one, and test for that.
-        with self.assertRaises(InterruptedError):
-            app.flush_workers("test_domain")
+        wg_flush_mock.side_effect = AttributeError(
+            "'NoneType' object has no attribute 'get'"
+        )
+
+        thread = threading.Thread(
+            target=app.flush_workers, args=("dummy_domain"), daemon=True
+        )
+        thread.start()
+
+        i = 0
+        while i < 20 and not wg_flush_mock.called:
+            i += 1
+            sleep(0.1)
+
+        wg_flush_mock.assert_called()
+        # Assert that the thread hasn't crashed and is still running
+        self.assertTrue(thread.is_alive())
+        # If Python would allow it without writing custom signalling, this would be the place to stop the thread again
 
 
 if __name__ == "__main__":

wgkex/worker/netlink.py

@@ -72,13 +72,12 @@ def wg_flush_stale_peers(domain: str) -> List[Dict]:
     stale_clients = [
         stale_client for stale_client in find_stale_wireguard_clients("wg-" + domain)
     ]
-    logger.debug("Found stale clients: %s", stale_clients)
-    logger.info("Searching for stale WireGuard clients.")
+    logger.debug("Found %s stale clients: %s", len(stale_clients), stale_clients)
     stale_wireguard_clients = [
         WireGuardClient(public_key=stale_client, domain=domain, remove=True)
         for stale_client in stale_clients
     ]
-    logger.debug("Found stable WireGuard clients: %s", stale_wireguard_clients)
+    logger.debug("Found stale WireGuard clients: %s", stale_wireguard_clients)
     logger.info("Processing clients.")
     link_handled = [
         link_handler(stale_client) for stale_client in stale_wireguard_clients
@@ -205,8 +204,8 @@ def find_stale_wireguard_clients(wg_interface: str) -> List:
         ret = [
             peer.get_attr("WGPEER_A_PUBLIC_KEY").decode("utf-8")
             for peer in all_peers
-            if peer.get_attr("WGPEER_A_LAST_HANDSHAKE_TIME").get("tv_sec", int())
-            < three_hrs_in_secs
+            if (hshk_time := peer.get_attr("WGPEER_A_LAST_HANDSHAKE_TIME")) is not None
+            and hshk_time.get("tv_sec", int()) < three_hrs_in_secs
         ]
         return ret