#mod_h[ttp]2 - http/2 for Apache httpd

Copyright (C) 2015, 2016 greenbytes GmbH

This repository contains mod_h[ttp]2 and mod_proxy_h[ttp]2 from Apache httpd as a standalone build.

##Status mod_h[ttp]2 is an official Apache httpd module, first released in 2.4.17. See Apache downloads to get a released version. mod_proxy_h[ttp]2 is part of Apache httpd development, but has not been released yet.

What you find here are early experience versions for people who like living on the edge and want to help me test not yet released changes.

If you want HTTP/2 in your production environment, please head over to the official releases at Apache and grab one of those or wait until the various OS distributions have assembled one for you.

##Current Version The versions here are early experience versions, based on Apache httpd 2.4.23. There is no guarantee that these will be released unchanged by Apache. But you are welcome to test it and give feedback.

##Install

You need a built Apache httpd 2.4.23, including apxs and headers to compile and run this module. Additionally, you need an installed libnghttp2, at least in version 1.3.0. And additionally, you want an installed OpenSSL 1.0.2.

tl;dr

You need an installed Apache 2.4.23 which already runs mod_http2 in it.

If you do not have that or don't know how to get it, look at google, stackoverflow, Apache mailing lists or your Linux distro. Not here!

##Apache 2.4.x Packages

• Ubuntu: ppa by ondrej for Ubuntu 14.04 and others
• Fedora: Rawhide includes httpd 2.4.17
• Debian sid (unstable) includes httpd 2.4.17. See how to install debian sid
• Gentoo: latest stable includes httpd 2.4.17+
• FreeBSD: Apache 2.4 port includes mod_http2 / mod_http2-devel port in review

##Changes

See ChangeLog for details.

##mod_proxy_http2

This module is part of the Apache httpd proxy architecture and functions similar to mod_proxy_http and friends. To configure it, you need to use h2: or h2c: in the proxy URL. Example:

<Proxy "balancer://h2-local">
    BalancerMember "h2://test.example.org:SUBST_PORT_HTTPS_SUBST"
</Proxy>
<Proxy "balancer://h2c-local">
    BalancerMember "h2c://test.example.org:SUBST_PORT_HTTP_SUBST"
</Proxy>

<IfModule proxy_http2_module>
    ProxyPass "/h2proxy" "balancer://h2-local"
    ProxyPassReverse "/h2proxy" "balancer://h2-local"
    ProxyPass "/h2cproxy" "balancer://h2c-local"
    ProxyPassReverse "/h2cproxy" "balancer://h2c-local"
</IfModule>

This will only work under the following conditions:

• the backend speaks HTTP/2, the module will not fallback to HTTP/1.1
• the backend supports HTTP/2 direct mode (see also H2Direct directive of mod_http2)

All other common httpd proxy directives also apply.

What it will not do and what is untested:

• fallback to HTTP/1.1
• be very smart when the number of concurrent streams in the backend differs from the local settings
• load balance between open connections dynamically
• forward any HTTP/2 priority information
• support HTTP/2 PUSH from the backend

What it will do:

• work with frontend HTTP/1.1 connections
• reuse open HTTP/2 connections from the balancer
• with a frontent HTTP/2 connection, all streams against the same backend will be handled in a single thread.

##Documenation There is the official Apache documentation of the module, which you will not find here.

I also compiled a how to h2 in apache document with advice on how to deploy, configure and verify your mod_h[ttp]2 installation.

##Build from git Still not dissuaded? Ok, here are some hints to get you started. Building from git is easy, but please be sure that at least autoconf 2.68 is used:

> autoreconf -i
> automake
> autoconf
> ./configure --with-apxs=<path to apxs>
> make

##Licensing Please see the file called LICENSE.

##Credits This work has been funded by the GSM Association (http://gsma.com). The module itself was heavily influenced by mod_spdy, the Google implementation of their SPDY protocol. And without Tatsuhiro Tsujikawa excellent nghttp2 work, this would not have been possible.

Münster, 19.04.2016,

Stefan Eissing, greenbytes GmbH

Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved. This file is offered as-is, without warranty of any kind. See LICENSE for details.