dsf-python-3.6.0rc1 http endpoint not working for me

achrn

I've tried DSF http endpoints on 3.6.0 rc1 and it's not working for me in exactly the same way as it didn't in 3.5.1 (which is described here: https://forum.duet3d.com/topic/35700/dsf-python-3-5-1rc1-problems-with-http-endpoint-not-working?_=1742631997497 but I shall recap):

Duet 3 MB6HC MB6HC 3.6.0-rc.1
Duet 3 Expansion TOOL1LC TOOL1LC 3.6.0-rc.1
Duet Software Framework DSF 3.6.0-rc.1
Duet Web Control DWC 3.6.0-rc.1
Raspberry Pi 4 Model B Rev 1.2
Linux delta.XXXXXX 6.6.74+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.6.74-1+rpt1 (2025-01-27) aarch64 GNU/Linux
from a Bookworm DuetPi image initially

dsf 3.6 is not currently in the package repository, I got it from https://pypi.org/project/dsf-python/3.6.0rc1/ and did sudo pip3 install --break-system-packages dsf-python==3.6.0rc1

The custom_http_endpoint.py script does not seem to be in the 3.6.0rc1 source from pypi, but I used the one from 3.5 (I'll add it to the bottom of this post).

Script output looks like it's working:

send: {"mode":"Command","version":12}
recv: {"success":true}
send: {"command":"AddHttpEndpoint","endpointType":"GET","namespace":"custom","path":"getIt","isUploadRequest":false}
recv: {"success":true,"result":"/run/dsf/custom/getIt-GET.sock"}
Try accessing http://duet3.local/machine/custom/getIt in your browser...

as it starts up, then when I make a connection:

recv: {"sessionId":-1,"queries":{},"headers":{"Accept":"*/*","Connection":"keep-alive","Host":"localhost","User-Agent":"Wget/1.21.3","Accept-Encoding":"identity"},"contentType":null,"body":""}
send: {"statusCode": 200, "response": "so happy you asked for it!", "responseType": "statuscode"}

However, there's no data received (I used wget on the same machine to bypass any networking shenanigans):

@delta:~ $  wget -S http://localhost/machine/custom/getIt
--2025-03-22 09:20:35--  http://localhost/machine/custom/getIt
Resolving localhost (localhost)... ::1, 127.0.0.1
Connecting to localhost (localhost)|::1|:80... connected.
HTTP request sent, awaiting response...
  HTTP/1.1 200 OK
  Content-Length: 0
  Date: Sat, 22 Mar 2025 09:20:35 GMT
  Server: Kestrel
Length: 0
Saving to: ‘getIt’

getIt                             [ <=>                                              ]       0  --.-KB/s    in 0s

2025-03-22 09:20:35 (0.00 B/s) - ‘getIt’ saved [0/0]

It has zero content length.

User running custom_http_endpoint.py is a normal user but member of dsf group.
Running as root doesn't help.
Socket has permissions srwxrwxr-x 1 user dsf 0 Mar 22 09:17 getIt-GET.sock

Journal log looks OK

Mar 22 09:23:48 delta.XXXXXX DuetWebServer[750]: Microsoft.AspNetCore.Hosting.Diagnostics[1] Request starting HTTP/1.1 GET http://localhost/machine/custom/getIt - - -
Mar 22 09:23:48 delta.XXXXXX DuetWebServer[750]: DuetWebServer.Singletons.SessionStorage[0] Session 7e5e184ecf1c475fb53104344d27ab60 added (readWrite)
Mar 22 09:23:48 delta.XXXXXX DuetWebServer[750]: Microsoft.AspNetCore.Hosting.Diagnostics[2] Request finished HTTP/1.1 GET http://localhost/machine/custom/getIt - 200 0 - 23.2772ms

Accessing the URL from a PC on the local network with Edge doesn't get any content either. I haven't tried further browsers (but I did last time).

This is the endpoint script I'm using:

#!/usr/bin/env python3

"""
Example to create a custom GET endpoint at http://duet3/machine/custom/getIt

Make sure when running this script to have access to the DSF UNIX socket owned by the dsf user.
"""

import time

from dsf.connections import CommandConnection
from dsf.http import HttpEndpointConnection
from dsf.object_model import HttpEndpointType


async def respond_something(http_endpoint_connection: HttpEndpointConnection):
    await http_endpoint_connection.read_request()
    await http_endpoint_connection.send_response(200, "so happy you asked for it!")
    http_endpoint_connection.close()


def custom_http_endpoint():
    cmd_conn = CommandConnection(debug=True)
    cmd_conn.connect()

    # Setup the endpoint
    endpoint = cmd_conn.add_http_endpoint(HttpEndpointType.GET, "custom", "getIt")
    # Register our handler to reply on requests
    endpoint.set_endpoint_handler(respond_something)

    print("Try accessing http://duet3.local/machine/custom/getIt in your browser...")

    return cmd_conn, endpoint


if __name__ == "__main__":
    try:
        cmd_conn, endpoint = custom_http_endpoint()
        # This just simulates doing other things as the new endpoint handler runs async
        time.sleep(1800)
    finally:
        if endpoint is not None:
            endpoint.close()
        cmd_conn.close()

chrishamm

@achrn said in dsf-python-3.6.0rc1 http endpoint not working for me:

await http_endpoint_connection.send_response(200, "so happy you asked for it!")

This call looks wrong to me. I think you need to specify a third parameter like HttpResponseType.PlainText to actually send out data. Otherwise you only return a status code.

achrn

@chrishamm Thanks! That was it.

Changed the imports and the send.response() and now it works.

With hindsight I then find this change (and some others) had been made at https://github.com/Duet3D/dsf-python/blob/v3.6-dev/examples/custom_http_endpoint.py in early December last year, but I had missed that.