fix(api): keep the base path when a request is retried against the same host

.changeset/failover-retry-keeps-base-path.md

@@ -0,0 +1,5 @@
+---
+"livekit-api": patch
+---
+
+Keep the base path of the server URL when a failed request is retried against the same host.

livekit-api/livekit/api/twirp_client.py

@@ -305,8 +305,9 @@ async def request(
             )
             await asyncio.sleep(self._failover_backoff * (2**attempt))
             attempted.add(host_key(next_origin))
-            current_origin = next_origin
-            current_base = next_origin
+            if next_origin != current_origin:
+                current_origin = next_origin
+                current_base = next_origin
 
         raise RuntimeError("failover loop exited without returning")  # unreachable
 

tests/api/test_failover_unit.py

@@ -57,6 +57,7 @@ async def _call_single_host(
     attempts: List[int],
     *,
     host: str = "127.0.0.1",
+    base_path: str = "",
     discovery_hits: Optional[List[None]] = None,
 ) -> Room:
     """Runs one CreateRoom against a server, reached as ``host``, whose only
@@ -81,14 +82,14 @@ async def twirp(request: web.Request) -> web.StreamResponse:
         return resp
 
     app = web.Application()
-    app.router.add_post("/twirp/livekit.RoomService/CreateRoom", twirp)
+    app.router.add_post(f"{base_path}/twirp/livekit.RoomService/CreateRoom", twirp)
     app.router.add_get("/settings/regions", regions)
     async with TestServer(app) as server:
         connector = aiohttp.TCPConnector(resolver=_StaticResolver())
         async with aiohttp.ClientSession(connector=connector) as session:
             client = TwirpClient(
                 session,
-                f"http://{host}:{server.port}",
+                f"http://{host}:{server.port}{base_path}",
                 "livekit",
                 _failover_force=host == "127.0.0.1",
                 _failover_backoff=0.001,
@@ -142,6 +143,20 @@ def behave(attempt: int, request: web.Request):
     assert len(attempts) == 2
 
 
+def test_same_host_retry_keeps_the_base_path():
+    """A retry against the same host keeps the base path of the configured URL."""
+
+    def behave(attempt: int, request: web.Request):
+        return None if attempt == 0 else _ok(request)
+
+    attempts: List[int] = []
+    room = asyncio.run(
+        _call_single_host(behave, attempts, host="cloud-api.livekit.io", base_path="/livekit")
+    )
+    assert room.name == "r"
+    assert len(attempts) == 2
+
+
 @pytest.mark.parametrize(
     "host, expected",
     [