Add try except to messaging connection

src/blueapi/messaging/stomptemplate.py

@@ -180,12 +180,17 @@ def finished_connecting(_: Frame):
         self._listener.on_disconnected = self._on_disconnected
 
         LOGGER.info("Connecting...")
-        self._conn.connect(
-            username=self._authentication.username,
-            passcode=self._authentication.passcode,
-            wait=True,
-        )
-        connected.wait()
+
+        try:
+            self._conn.connect(
+                username=self._authentication.username,
+                passcode=self._authentication.passcode,
+                wait=True,
+            )
+            connected.wait()
+        except ConnectFailedException as ex:
+            LOGGER.exception(msg="Failed to connect to message bus", exc_info=ex)
+
         self._ensure_subscribed()
 
     def _ensure_subscribed(self, sub_ids: Optional[List[str]] = None) -> None:

tests/messaging/test_stomptemplate.py

@@ -4,7 +4,10 @@
 from typing import Any, Iterable, List, Type
 
 import pytest
+from mock import ANY, MagicMock, patch
 from pydantic import BaseModel, BaseSettings, Field
+from stomp import Connection
+from stomp.exception import ConnectFailedException
 
 from blueapi.config import StompConfig
 from blueapi.messaging import MessageContext, MessagingTemplate, StompMessagingTemplate
@@ -159,6 +162,29 @@ def test_reconnect(template: MessagingTemplate, test_queue: str) -> None:
     assert reply == "ack"
 
 
+@pytest.fixture()
+def failing_template() -> MessagingTemplate:
+    def connection_exception(*args, **kwargs):
+        raise ConnectFailedException
+
+    connection = Connection()
+    connection.connect = MagicMock(side_effect=connection_exception)
+    return StompMessagingTemplate(connection)
+
+
+@pytest.mark.stomp
+def test_failed_connect(failing_template: MessagingTemplate, test_queue: str) -> None:
+    assert not failing_template.is_connected()
+    with patch(
+        "blueapi.messaging.stomptemplate.LOGGER.error", autospec=True
+    ) as mock_logger:
+        failing_template.connect()
+        assert not failing_template.is_connected()
+        mock_logger.assert_called_once_with(
+            "Failed to connect to message bus", exc_info=ANY
+        )
+
+
 @pytest.mark.stomp
 def test_correlation_id(
     template: MessagingTemplate, test_queue: str, test_queue_2: str