1968731765
This mostly reverts commit ff8db5a85 ("BUG/MINOR: config: Stopped parsing
upon unmatched environment variables").
As explained in commit #2367, finally the fix above was incorrect because
it causes other trouble such as this:
log "192.168.100.${NODE}" "local0"
being resolved to this:
log 192.168.100.local0
when NODE does not exist due to the loss of the spaces. In fact, while none
of us was well aware of this, when the user had:
server app 127.0.0.1:80 "${NO_CHECK}" weight 123
in fact they should have written it this way:
server app 127.0.0.1:80 "${NO_CHECK[*]}" weight 123
so that the variable is expanded to zero, one or multiple words, leaving
no empty arg (like in shell). This is supported since 2.3 with commit
fa41cb6 so the right fix is in the config, let's revert the fix and
properly address the issue.
Some changes are necessary however, since after that patch, the in_arg
checks were added and are now inserting an empty argument even for
proper error reporting. For example, the following statement:
acl foo path "/a" "${FOO[*]}" "/b"
would complain about an empty arg at FOO due to in_arg=1, while dropping
this in_arg=1 with the following config:
acl foo path "/a" "${FOO}" "/b"
would silently stop after "/a" instead of complaining about an empty
field. So the approach here consists in noting whether or not something
was written since the quotes were emitted, in order to decide whether
or not to produce an argument. This way, "" continues to be an explicitly
empty arg, just like the same with an unknown variable, while "${FOO[*]}"
is allowed to prevent the creation of an argument if empty.
This should be backported to *some* versions, but the risk that some
configs were altered to rely on the broken fix is not null. At least
recent LTS should be reverted. Note that this requires previous commit:
BUG/MINOR: config: emit warning for empty args when *not* in discovery mode
otherwise this will break again configs relying on HAPROXY_LOCALPEER and
maybe a few other variables set at the end of discovery.
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.