send error in streaming response

2 files changed, 9 insertions, 5 deletions

diff --git a/kvmd/apps/kvmd/api/msd.py b/kvmd/apps/kvmd/api/msd.py
index a8d44e5e..c2ec746f 100644
--- a/kvmd/apps/kvmd/api/msd.py
+++ b/kvmd/apps/kvmd/api/msd.py
@@ -106,9 +106,9 @@ class MsdApi:
         size = written = 0
         response: Optional[StreamResponse] = None
 
-        async def stream_write_info() -> None:
+        async def stream_write_info(err: Optional[Exception]=None) -> None:
             assert response is not None
-            await stream_json(response, self.__make_write_info(name, size, written))
+            await stream_json(response, self.__make_write_info(name, size, written), err)
 
         try:
             async with htclient.download(
@@ -141,7 +141,7 @@ class MsdApi:
 
         except Exception as err:
             if response is not None:
-                await stream_write_info()
+                await stream_write_info(err)
             elif isinstance(err, aiohttp.ClientError):
                 return make_json_exception(err, 400)
             raise
diff --git a/kvmd/apps/kvmd/http.py b/kvmd/apps/kvmd/http.py
index 9ffed1d4..9649a995 100644
--- a/kvmd/apps/kvmd/http.py
+++ b/kvmd/apps/kvmd/http.py
@@ -178,8 +178,12 @@ async def start_streaming(request: Request, content_type: str) -> StreamResponse
     return response
 
 
-async def stream_json(response: StreamResponse, result: Dict) -> None:
-    await response.write(json.dumps(result).encode("utf-8") + b"\r\n")
+async def stream_json(response: StreamResponse, result: Dict, err: Optional[Exception]=None) -> None:
+    await response.write(json.dumps({
+        "result": result,
+        "error": ("" if err is None else type(err).__name__),
+        "error_msg": ("" if err is None else str(err)),
+    }).encode("utf-8") + b"\r\n")
 
 
 # =====