Saturday, April 9, 2022

[SOLVED] openbsd httpd with gunicorn+uvicorn -- Remote protocol error : illegal request line

Issue

My web deployment setup is on openBSD and consists of httpd on front with guicorn + uvicorn as the back engine, connected via unix socket.

The setup works, in the sense that requests from httpd are being forwarded to gunicorn over the unix sockets. However, the gunicorn/uvicorn is not able to understand the incoming http request. The error stack

[2021-11-22 22:52:17 +0530] [1631] [WARNING] Invalid HTTP request received.
Traceback (most recent call last):
  File "/home/shared/Builds/Python-3.10.0/lib/python3.10/site-packages/uvicorn/protocols/http/h11_impl.py", line 136, in handle_events
    event = self.conn.next_event()
  File "/home/shared/Builds/Python-3.10.0/lib/python3.10/site-packages/h11/_connection.py", line 443, in next_event
    exc._reraise_as_remote_protocol_error()
  File "/home/shared/Builds/Python-3.10.0/lib/python3.10/site-packages/h11/_util.py", line 76, in _reraise_as_remote_protocol_error
    raise self
  File "/home/shared/Builds/Python-3.10.0/lib/python3.10/site-packages/h11/_connection.py", line 425, in next_event
    event = self._extract_next_receive_event()
  File "/home/shared/Builds/Python-3.10.0/lib/python3.10/site-packages/h11/_connection.py", line 367, in _extract_next_receive_event
    event = self._reader(self._receive_buffer)
  File "/home/shared/Builds/Python-3.10.0/lib/python3.10/site-packages/h11/_readers.py", line 68, in maybe_read_from_IDLE_client
    raise LocalProtocolError("illegal request line")
h11._util.RemoteProtocolError: illegal request line

I am not sure what are potential causes for illegal request line.


Solution

httpd is not support http proxying. It is support serving static files as well as FastCGI. And error message, indicate that your httpd try to communicate with gunicorn using FastCGI.

So, if you stick to httpd, find a way to run your app using FastCGI server instead of WSGI (gunicorn). Many years ago flup was a popular choice.

Or, just use Nginx instead of httpd.



Answered By - Zada Zorg
Answer Checked By - Pedro (WPSolving Volunteer)
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