Possible bug http2 module

[Валентин Бартенев]

On Saturday 06 February 2016 12:44:08 Jim Ohlstein wrote:
> On 2/6/16 12:22 PM, Валентин Бартенев wrote:
> > On Saturday 06 February 2016 12:13:52 Jim Ohlstein wrote:
> >> Hello,
> >> 
> >> I am running a WordPress multisite install and recently turned off http2
> >> on the domain in order to use a third party module which evidently
> >> doesn't play nicely with http2 (echo module). In testing I noticed that
> >> the site was still being served with http2 enabled according to both
> >> Chrome and Firefox. I confirmed with curl.
> >> 
> >> I recompiled nginx without any third party modules:
> >> 
> >> # nginx -V
> >> nginx version: nginx/1.9.10
> >> built with OpenSSL 1.0.2f  28 Jan 2016
> >> TLS SNI support enabled
> >> configure arguments: --prefix=/usr/local/etc/nginx --with-cc-opt='-I
> >> /usr/local/include' --with-ld-opt='-L /usr/local/lib'
> >> --conf-path=/usr/local/etc/nginx/nginx.conf
> >> --sbin-path=/usr/local/sbin/nginx --pid-path=/var/run/nginx.pid
> >> --error-log-path=/var/log/nginx-error.log --user=www --group=www
> >> --with-file-aio --with-ipv6
> >> --http-client-body-temp-path=/var/tmp/nginx/client_body_temp
> >> --http-fastcgi-temp-path=/var/tmp/nginx/fastcgi_temp
> >> --http-proxy-temp-path=/var/tmp/nginx/proxy_temp
> >> --http-scgi-temp-path=/var/tmp/nginx/scgi_temp
> >> --http-uwsgi-temp-path=/var/tmp/nginx/uwsgi_temp
> >> --http-log-path=/var/log/nginx-access.log --with-http_stub_status_module
> >> --with-pcre --with-http_v2_module --with-http_ssl_module
> >> 
> >> 
> >> I then adjusted the config files so as not to reference any third party
> >> modules and performed a binary "upgrade".
> >> 
> >> I still see that http2 is in use on both Chrome and Firefox, and also
> >> via curl.
> >> 
> >> # curl -I -k https://my.ip4.add.ress/
> >> HTTP/2.0 302
> >> server:nginx/1.9.10
> >> date:Sat, 06 Feb 2016 16:49:44 GMT
> >> content-type:text/html; charset=UTF-8
> >> 
> >> # curl -I https:/mydomain.net/
> >> HTTP/2.0 200
> >> server:nginx/1.9.10
> >> date:Sat, 06 Feb 2016 16:50:41 GMT
> >> content-type:text/html; charset=UTF-8
> >> 
> >> There are other domains on that IPv4 which use http2. Disabling http2 on
> >> all of them resulted in the expected behavior in the browsers and in
> >> curl:
> >> 
> >> # curl -I -k https:///my.ip4.add.ress/
> >> HTTP/1.1 302 Moved Temporarily
> >> Server: nginx/1.9.10
> >> Date: Sat, 06 Feb 2016 17:03:39 GMT
> >> Content-Type: text/html; charset=UTF-8
> >> Connection: keep-alive
> >> 
> >> # curl -I https://mydomain.net/
> >> HTTP/1.1 200 OK
> >> Server: nginx/1.9.10
> >> Date: Sat, 06 Feb 2016 17:05:05 GMT
> >> Content-Type: text/html; charset=UTF-8
> >> Connection: keep-alive
> >> 
> >> I don't see any reference to this at
> >> http://nginx.org/en/docs/http/ngx_http_v2_module.html so I am  guessing
> >> this is unintended.
> > 
> > [..]
> > 
> > A quote from the documentation:
> >   | The http2 parameter (1.9.5) configures the port to accept HTTP/2
> >   | connections.
> > 
> > http://nginx.org/en/docs/http/ngx_http_core_module.html#listen
> 
> Ahh. That's not in the http2 module documentation, where I looked and
> where it should perhaps also be mentioned, and it's not clear that the
> above applies to every server.
> 
> So if I write:
> 
> listen 443 ssl http2;
> 
> in a server directive anywhere as dosumneted in
> http://nginx.org/en/docs/http/ngx_http_v2_module.html#example, then
> http2 is enabled in all servers on all IP's even if it's not
> specifically enabled in a listen directive in a particular server? That
> seems wrong, intuitively. There are (more and more) times when shared
> IPv4's are necessary, and dictating this behavior for all servers on a
> given IPv4 is probably less than optimal. If it's technically a
> necessity it could perhaps be more explicitly documented.

It's pretty much the same as "ssl" parameter works.

Ones connected an HTTP/2 client is able to request any host over the HTTP/2 
connection, and in fact browsers do.  So there's no proper way to disable
HTTP/2 for one virtual server while keeping enable for others.

Could you suggest a good phrase to improve the docs?

  wbr, Valentin V. Bartenev