ca773e1a2a
It's convenient to have a share lib be able to also work as a wrapper. But recent glibc broke support for this dual-mode thing some time ago: https://patchwork.ozlabs.org/project/glibc/patch/20190312130235.8E82C89CE49C@oldenburg2.str.redhat.com/ https://stackoverflow.com/questions/59074126/loading-executable-or-executing-a-library Trying to preload such an executable indeed returns: ERROR: ld.so: object '/path/to/ncpu.so' from LD_PRELOAD cannot be preloaded (cannot dynamically load position-independent executable): ignored. Note that the code still supports it since libc.so is both an executable and a lib. The approach taken here is the same as in the nousr.so wrapper. It consists in dropping the DF_1_PIE flag from the resulting executable since it's what the dynamic linker is looking for. This flag is found in FLAGS_1 in the .dynamic section. As readelf -a suggests, it's after the tag 0x6ffffffb. The value is 0x08000000. We're using objdump to figure the length and offset of the struct, dd to extract the 3 parts, and sed to patch the binary. It's likely that it will only work on 64-bit little endian, though tests should be performed to see what to do on other platforms. At least on x86_64, ld.so is happy and it continues to be possible to use the binary as a .so, and that the platform where most of the development happens so that's fine. In any case the wrapper and the standard shared lib are still made two distinct files so that it's possible to use the non-patched version on unsupported OSes or architectures.
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.