Our Linux Docker ASP.NET Core container server logs are getting filled by the following 'Informational' log entries since we've updated from .NET Core 2.0 to .NET Core 2.1 (SDK 2.1.302):
INFO|Microsoft.AspNetCore.Server.Kestrel|Connection id "0HLFG42JUAORG" bad request
data: "Invalid request line:
'CNXN\x00\x00\x00\x01\x00\x00\x04\x00\x1B\x00\x00\x00M\x0A'"
Microsoft.AspNetCore.Server.Kestrel.Core.BadHttpRequestException: Invalid
request line: 'CNXN\x00\x00\x00\x01\x00\x00\x04\x00\x1B\x00\x00\x00M\x0A'
INFO|Microsoft.AspNetCore.Server.Kestrel|Connection id "0HLFG42JUAORH" bad request
data: "Invalid request line:
'CNXN\x00\x00\x00\x01\x00\x00\x04\x00\x1B\x00\x00\x00M\x0A'"
Microsoft.AspNetCore.Server.Kestrel.Core.BadHttpRequestException: Invalid
request line: 'CNXN\x00\x00\x00\x01\x00\x00\x04\x00\x1B\x00\x00\x00M\x0A'
The connection ID is incrementing by 1 alpha/digit every second or so. The hex doesn't seem translate to anything meaningful (NUL NUL NUL SOH NUL NUL EOT NUL ESC NUL NUL LF
).
Things we've ruled out:
Turns out it was an issue with the docker host (debian) and hanging sockets (netstat showing a lot of TIME_WAITs). Changed the app port to a different one and the malformed requests stopped.
A reboot or restart of the docker daemon would probably also fix it, but the uptime of our other containers is vital so we weren't able to test that.