Catch case when not reconnected after instrument server goes down

Author: d-j-hatton

src/murfey/server/api/instrument.py

@@ -456,14 +456,17 @@ async def get_rsyncer_info(
         select(RsyncInstance).where(RsyncInstance.session_id == session_id)
     ).all()
     if machine_config.instrument_server_url:
-        async with lock:
-            token = instrument_server_tokens[session_id]["access_token"]
-        async with aiohttp.ClientSession() as clientsession:
-            async with clientsession.get(
-                f"{machine_config.instrument_server_url}/sessions/{sanitise(str(session_id))}/rsyncer_info",
-                headers={"Authorization": f"Bearer {token}"},
-            ) as resp:
-                data = await resp.json()
+        try:
+            async with lock:
+                token = instrument_server_tokens[session_id]["access_token"]
+            async with aiohttp.ClientSession() as clientsession:
+                async with clientsession.get(
+                    f"{machine_config.instrument_server_url}/sessions/{sanitise(str(session_id))}/rsyncer_info",
+                    headers={"Authorization": f"Bearer {token}"},
+                ) as resp:
+                    data = await resp.json()
+        except KeyError:
+            data = []
     combined_data = []
     data_source_lookup = {d["source"]: d for d in data}
     for ri in rsync_instances: