Expect: 100-continue

[tumb1er]

Is it supported in aiohttp.web server?

$> curl -v -include --form [email protected] http://192.168.70.104:8080/uploader/123/
*   Trying 192.168.70.104...
* Connected to 192.168.70.104 (192.168.70.104) port 8080 (#0)
> POST /uploader/123/ HTTP/1.1
> User-Agent: curl/7.35.0
> Host: 192.168.70.104:8080
> Accept: */*
> Content-Length: 408460805
> Expect: 100-continue
> Content-Type: multipart/form-data; boundary=------------------------9fa6693db84f46b3
> 
* Done waiting for 100-continue
< HTTP/1.1 200 OK

Nginx + Django response looks like this:

> POST /accounts/login/ HTTP/1.1
> User-Agent: curl/7.35.0
> Host: ***
> Accept: */*
> Expect: 100-continue
> Content-Type: application/x-www-form-urlencoded
> Content-Length: 96
> 
< HTTP/1.1 100 Continue
< HTTP/1.1 403 FORBIDDEN

Nginx responses with HTTP/1.1 100 Continue first.

[asvetlov]

I don't understand your question clean, sorry.
aiohttp.web has no embedded support for 100 but you can make response with 100 Continue status code by hands if needed.

[tumb1er]

No, if I make a response:

return Response(status=100)

aiohttp just closes connection. Curl output:

* Done waiting for 100-continue
< HTTP/1.1 100 Continue
HTTP/1.1 100 Continue
< CONTENT-LENGTH: 0
CONTENT-LENGTH: 0
< CONNECTION: keep-alive
CONNECTION: keep-alive
< DATE: Fri, 30 Jan 2015 16:12:43 GMT
DATE: Fri, 30 Jan 2015 16:12:43 GMT
* Server Python/3.4 aiohttp/0.14.4 is not blacklisted
< SERVER: Python/3.4 aiohttp/0.14.4
SERVER: Python/3.4 aiohttp/0.14.4

* Recv failure: Connection reset by peer
* Closing connection 0
curl: (56) Recv failure: Connection reset by peer

Working code is:

 request.transport.write(b"HTTP/1.1 100 Continue\r\n")

It is possible to handle authomatically in Request?

[fafhrd91]

@tumb1er what is your use case for 100-continue ?

[ludovic-gasc]

If it's like SIP protocol, it's to notify the client that the request is received, response will arrive.

[tumb1er]

@fafhrd91 it's only an observation of how curl works with post requests.
From here:

Upon receiving a request which includes an Expect request-header
field with the "100-continue" expectation, an origin server MUST
either respond with 100 (Continue) status and continue to read
from the input stream, or respond with a final status code. The
origin server MUST NOT wait for the request body before sending
the 100 (Continue) response. If it responds with a final status
code, it MAY close the transport connection or it MAY continue
to read and discard the rest of the request. It MUST NOT
perform the requested method if it returns a final status code.

[fafhrd91]

that is wrong reason for feature. by implementing this response you close ways to use this feature properly. i prefer no to have it rather have wrong implementation.

[tumb1er]

So every aiohttp user MUST now implement Expect: header processing by himself, to make aiohttp library HTTP/1.1 compatible?

I think, with Request.post() method behavior mentioned by RFC is clear enougth.

def handle(request):
  # First, check all request properties without reading a payload
  if check_headers_and_path(request) != "ok":
    # if not OK, send 417, or 403 or whatever else... (server MUST continue reading
    # or response with final status code)
    return Response(status=417)
  # if ok, request.post() sends 100-continue if necessary 
  # (without any other movements from aiohttp users)
  # and continue reading payload (that is what server 
  # MUST do if 100-continue is sent)
  yield from request.post()
  # do "perform request method" as in RFC
  result = do_usefull_stuff(request)
  return Response(text=result, status=200)

[fafhrd91]

you can create middleware that for that.

[fafhrd91]

well, you example already has different use case. so make pull request for your use case.

[lock]

This thread has been automatically locked since there has not been
any recent activity after it was closed. Please open a new issue for
related bugs.

If you feel like there's important points made in this discussion,
please include those exceprts into that new issue.