607aa57b2e
The following config is sufficient to trace H2 exchanges between a client
and a server:
global
lua-load "dev/h2/h2-tracer.lua"
listen h2_sniffer
mode tcp
bind :8002
filter lua.h2-tracer #hex
server s1 127.0.0.1:8003
The commented "hex" argument will also display full frames in hex (not
recommended). The connections are prefixed with a 3-hex digit number in
order to also support a bit of multiplexing without impacting the reading
too much. The screen is split in two, with the request on the left and
the response on the right. Here's an example of what it does between an
haproxy backend and an haproxy frontend both in H2, when submitted a
curl request for /?s=30k handled by httpterm:
[001] ### req start
[001] [PREFACE len=24]
[001] [SETTINGS sid=0 len=24 (bytes=24)]
[001] | ### res start
[001] | [SETTINGS sid=0 len=18 (bytes=27)]
[001] | [SETTINGS ACK sid=0 len=0 (bytes=0)]
[001] [SETTINGS ACK sid=0 len=0 (bytes=56)]
[001] [HEADERS EH+ES sid=1 len=47 (bytes=47)]
[001] | [HEADERS EH sid=1 len=101 (bytes=15351)]
[001] | [DATA sid=1 len=15126 (bytes=15241)]
[001] | [DATA sid=1 len=1258 (bytes=106)]
[001] | ... -106 = 1152
[001] | ... -1152 = 0
[001] [WINDOW_UPDATE sid=1 len=4 (bytes=43)]
[001] [WINDOW_UPDATE sid=0 len=4 (bytes=30)]
[001] [WINDOW_UPDATE sid=1 len=4 (bytes=17)]
[001] [WINDOW_UPDATE sid=0 len=4 (bytes=4)]
[001] | [DATA ES sid=1 len=14336 (bytes=14336)]
[001] [WINDOW_UPDATE sid=0 len=4 (bytes=4)]
[001] ### req end: 31080 bytes total
[001] | [GOAWAY sid=0 len=8 (bytes=8)]
[001] | ### res end: 31097 bytes total
It deserves some improvements. For instance at the moment it does not
verify the preface, any 24 bytes will work. It does not perform any
protocol validation either. Detecting some issues such as out-of-sequence
frames could be helpful. But it already helps as-is.
HAProxy
HAProxy is a free, very fast and reliable reverse-proxy offering high availability, load balancing, and proxying for TCP and HTTP-based applications.
Installation
The INSTALL file describes how to build HAProxy. A list of packages is also available on the wiki.
Getting help
The discourse and the mailing-list are available for questions or configuration assistance. You can also use the slack or IRC channel. Please don't use the issue tracker for these.
The issue tracker is only for bug reports or feature requests.
Documentation
The HAProxy documentation has been split into a number of different files for ease of use. It is available in text format as well as HTML. The wiki is also meant to replace the old architecture guide.
Please refer to the following files depending on what you're looking for:
- INSTALL for instructions on how to build and install HAProxy
- BRANCHES to understand the project's life cycle and what version to use
- LICENSE for the project's license
- CONTRIBUTING for the process to follow to submit contributions
The more detailed documentation is located into the doc/ directory:
- doc/intro.txt for a quick introduction on HAProxy
- doc/configuration.txt for the configuration's reference manual
- doc/lua.txt for the Lua's reference manual
- doc/SPOE.txt for how to use the SPOE engine
- doc/network-namespaces.txt for how to use network namespaces under Linux
- doc/management.txt for the management guide
- doc/regression-testing.txt for how to use the regression testing suite
- doc/peers.txt for the peers protocol reference
- doc/coding-style.txt for how to adopt HAProxy's coding style
- doc/internals for developer-specific documentation (not all up to date)
License
HAProxy is licensed under GPL 2 or any later version, the headers under LGPL 2.1. See the LICENSE file for a more detailed explanation.