HTTP2 without TLS

The README explains how to set up HTTP2 with TLS, but there’s no indication of how to set it up without TLS.

Just for context: my interest in doing this is because my load balancer already does the TLS termination. There’s little sense in me setting up a pipeline to provision certificates to my django instances – and the overhead of TLS between the load balancer and Django doesn’t really make sense.

I’ve installed the optional dependencies:

pip install -U 'Twisted[tls,http2]'

And daphne indicates it supports HTTP2:

root@e4376f859b81:/app# bash scripts/run-django
[   DEBUG 2020-11-02 12:09:40] django.request:120  Asynchronous middleware django.middleware.clickjacking.XFrameOptionsMiddleware adapted.
[   DEBUG 2020-11-02 12:09:40] asyncio:59  Using selector: EpollSelector
[    INFO 2020-11-02 12:09:40] daphne.cli:287  Starting server at tcp:port=8000:interface=0.0.0.0
[    INFO 2020-11-02 12:09:40] daphne.server:108  HTTP/2 support enabled
[    INFO 2020-11-02 12:09:40] daphne.server:119  Configuring endpoint tcp:port=8000:interface=0.0.0.0
[    INFO 2020-11-02 12:09:40] daphne.server:150  Listening on TCP address 0.0.0.0:8000

However, it does not seem to actually operate on HTTP2, even using things like:

❯ curl -vI HEAD --http2 http://www.myapp.localhost:8000/
* Could not resolve host: HEAD
* Closing connection 0
curl: (6) Could not resolve host: HEAD
*   Trying ::1:8000...
* Connected to www.myapp.localhost (::1) port 8000 (#1)
> HEAD / HTTP/1.1
> Host: www.myapp.localhost:8000
> User-Agent: curl/7.73.0
> Accept: */*
> Connection: Upgrade, HTTP2-Settings
> Upgrade: h2c
> HTTP2-Settings: AAMAAABkAAQCAAAAAAIAAAAA
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< Content-Type: text/html; charset=utf-8
Content-Type: text/html; charset=utf-8
< X-Frame-Options: DENY
X-Frame-Options: DENY
< Vary: Cookie, Accept-Language
Vary: Cookie, Accept-Language
< Content-Length: 433909
Content-Length: 433909
< Content-Language: es
Content-Language: es

Am I testing this wrong, or would additional changes be required for daphne to support this?

[WhyNotHugo]

all browsers only support HTTP/2 with TLS

Yup, I’m quite aware of this.

This is not my case though; I have daphne behind a load balancer. Using a LB or another proxy that does the TLS termination is not unusual.

[moritz89]

@carltongibson It seems that this can be implemented by simply using a different Twisted endpoint class. Instead of using SSL4ServerEndpoint replace it with TCP4ServerEndpoint. I’m referring to this Twisted example.