41ca89bc6f
With 7a21c3a ("MAJOR: log: implement proper postparsing for logformat
expressions") which finally made postparsing checks reliable, we started
to get report from users that couldn't start haproxy 3.0 with configs that
used to work in the past. The current situation is described in GH #2642.
While the checks are mostly relevant, it turns out there are not strictly
needed anymore from a technical point of view. Most of them were useful in
early logformat implementation to prevent runtime bugs due to the use of
an alias or fetch at runtime from an incompatible proxy. It's been a few
versions already that the code handling fetches and log aliases is robust
enough to support fetches/aliases used from the wrong context: all it
does is that the fetch/alias will silently fail if it's not available.
This can be proved by the fact that even if the postparsing checks were
partially broken in the past, it didn't cause runtime issues (at least
on recent haproxy versions).
Most of these checks can now be seen as configuration hints: when a check
triggers, it will indicate a configuration inconsistency in most cases,
but they are some corner cases where it is not possible to know at config
time if the conditions will be met for the alias/fetch to work properly..
so instead of failing with a hard error like we did so far, let's just be
more permissive and report our findings using "diag_warning": such
warnings are only emitted when haproxy is started with '-dD' cli option.
We also took this opportunity to improve messages clarity and make them
more precise (report the offending item instead of complaining about the
whole expression because of a single element).
With this patch, configs that used to start before 7a21c3a shouldn't
trigger hard errors anymore.
This may be backported in 3.0.
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.