mirror of
http://git.haproxy.org/git/haproxy.git/
synced 2024-12-26 06:32:13 +00:00
657 lines
31 KiB
Plaintext
657 lines
31 KiB
Plaintext
----------------------
|
||
HAProxy how-to
|
||
----------------------
|
||
version 1.6-dev
|
||
willy tarreau
|
||
2015/03/11
|
||
|
||
|
||
1) How to build it
|
||
------------------
|
||
|
||
First, please note that this version is a development version, so in general if
|
||
you are not used to build from sources or if you don't have the time to track
|
||
very frequent updates, it is recommended that instead you switch to the stable
|
||
version (1.5) or follow the packaged updates provided by your software vendor
|
||
or Linux distribution. Most of them are taking this task seriously and are
|
||
doing a good job. If for any reason you'd prefer a different version than the
|
||
one packaged for your system, or to get some commercial support, other choices
|
||
are available at :
|
||
|
||
http://www.haproxy.com/
|
||
|
||
To build haproxy, you will need :
|
||
- GNU make. Neither Solaris nor OpenBSD's make work with the GNU Makefile.
|
||
If you get many syntax errors when running "make", you may want to retry
|
||
with "gmake" which is the name commonly used for GNU make on BSD systems.
|
||
- GCC between 2.95 and 4.8. Others may work, but not tested.
|
||
- GNU ld
|
||
|
||
Also, you might want to build with libpcre support, which will provide a very
|
||
efficient regex implementation and will also fix some badness on Solaris' one.
|
||
|
||
To build haproxy, you have to choose your target OS amongst the following ones
|
||
and assign it to the TARGET variable :
|
||
|
||
- linux22 for Linux 2.2
|
||
- linux24 for Linux 2.4 and above (default)
|
||
- linux24e for Linux 2.4 with support for a working epoll (> 0.21)
|
||
- linux26 for Linux 2.6 and above
|
||
- linux2628 for Linux 2.6.28, 3.x, and above (enables splice and tproxy)
|
||
- solaris for Solaris 8 or 10 (others untested)
|
||
- freebsd for FreeBSD 5 to 10 (others untested)
|
||
- osx for Mac OS/X
|
||
- openbsd for OpenBSD 3.1 to 5.2 (others untested)
|
||
- aix51 for AIX 5.1
|
||
- aix52 for AIX 5.2
|
||
- cygwin for Cygwin
|
||
- generic for any other OS or version.
|
||
- custom to manually adjust every setting
|
||
|
||
You may also choose your CPU to benefit from some optimizations. This is
|
||
particularly important on UltraSparc machines. For this, you can assign
|
||
one of the following choices to the CPU variable :
|
||
|
||
- i686 for intel PentiumPro, Pentium 2 and above, AMD Athlon
|
||
- i586 for intel Pentium, AMD K6, VIA C3.
|
||
- ultrasparc : Sun UltraSparc I/II/III/IV processor
|
||
- native : use the build machine's specific processor optimizations. Use with
|
||
extreme care, and never in virtualized environments (known to break).
|
||
- generic : any other processor or no CPU-specific optimization. (default)
|
||
|
||
Alternatively, you may just set the CPU_CFLAGS value to the optimal GCC options
|
||
for your platform.
|
||
|
||
You may want to build specific target binaries which do not match your native
|
||
compiler's target. This is particularly true on 64-bit systems when you want
|
||
to build a 32-bit binary. Use the ARCH variable for this purpose. Right now
|
||
it only knows about a few x86 variants (i386,i486,i586,i686,x86_64), two
|
||
generic ones (32,64) and sets -m32/-m64 as well as -march=<arch> accordingly.
|
||
|
||
If your system supports PCRE (Perl Compatible Regular Expressions), then you
|
||
really should build with libpcre which is between 2 and 10 times faster than
|
||
other libc implementations. Regex are used for header processing (deletion,
|
||
rewriting, allow, deny). The only inconvenient of libpcre is that it is not
|
||
yet widely spread, so if you build for other systems, you might get into
|
||
trouble if they don't have the dynamic library. In this situation, you should
|
||
statically link libpcre into haproxy so that it will not be necessary to
|
||
install it on target systems. Available build options for PCRE are :
|
||
|
||
- USE_PCRE=1 to use libpcre, in whatever form is available on your system
|
||
(shared or static)
|
||
|
||
- USE_STATIC_PCRE=1 to use a static version of libpcre even if the dynamic
|
||
one is available. This will enhance portability.
|
||
|
||
- with no option, use your OS libc's standard regex implementation (default).
|
||
Warning! group references on Solaris seem broken. Use static-pcre whenever
|
||
possible.
|
||
|
||
Recent systems can resolve IPv6 host names using getaddrinfo(). This primitive
|
||
is not present in all libcs and does not work in all of them either. Support in
|
||
glibc was broken before 2.3. Some embedded libs may not properly work either,
|
||
thus, support is disabled by default, meaning that some host names which only
|
||
resolve as IPv6 addresses will not resolve and configs might emit an error
|
||
during parsing. If you know that your OS libc has reliable support for
|
||
getaddrinfo(), you can add USE_GETADDRINFO=1 on the make command line to enable
|
||
it. This is the recommended option for most Linux distro packagers since it's
|
||
working fine on all recent mainstream distros. It is automatically enabled on
|
||
Solaris 8 and above, as it's known to work.
|
||
|
||
It is possible to add native support for SSL using the GNU makefile, by passing
|
||
"USE_OPENSSL=1" on the make command line. The libssl and libcrypto will
|
||
automatically be linked with haproxy. Some systems also require libz, so if the
|
||
build fails due to missing symbols such as deflateInit(), then try again with
|
||
"ADDLIB=-lz".
|
||
|
||
To link OpenSSL statically against haproxy, build OpenSSL with the no-shared
|
||
keyword and install it to a local directory, so your system is not affected :
|
||
|
||
$ export STATICLIBSSL=/tmp/staticlibssl
|
||
$ ./config --prefix=$STATICLIBSSL no-shared
|
||
$ make && make install_sw
|
||
|
||
When building haproxy, pass that path via SSL_INC and SSL_LIB to make and
|
||
include additional libs with ADDLIB if needed (in this case for example libdl):
|
||
|
||
$ make TARGET=linux26 USE_OPENSSL=1 SSL_INC=$STATICLIBSSL/include SSL_LIB=$STATICLIBSSL/lib ADDLIB=-ldl
|
||
|
||
It is also possible to include native support for ZLIB to benefit from HTTP
|
||
compression. For this, pass "USE_ZLIB=1" on the "make" command line and ensure
|
||
that zlib is present on the system. Alternatively it is possible to use libslz
|
||
for a faster, memory less, but slightly less efficient compression, by passing
|
||
"USE_SLZ=1".
|
||
|
||
By default, the DEBUG variable is set to '-g' to enable debug symbols. It is
|
||
not wise to disable it on uncommon systems, because it's often the only way to
|
||
get a complete core when you need one. Otherwise, you can set DEBUG to '-s' to
|
||
strip the binary.
|
||
|
||
For example, I use this to build for Solaris 8 :
|
||
|
||
$ make TARGET=solaris CPU=ultrasparc USE_STATIC_PCRE=1
|
||
|
||
And I build it this way on OpenBSD or FreeBSD :
|
||
|
||
$ gmake TARGET=freebsd USE_PCRE=1 USE_OPENSSL=1 USE_ZLIB=1
|
||
|
||
And on a classic Linux with SSL and ZLIB support (eg: Red Hat 5.x) :
|
||
|
||
$ make TARGET=linux26 USE_PCRE=1 USE_OPENSSL=1 USE_ZLIB=1
|
||
|
||
And on a recent Linux >= 2.6.28 with SSL and ZLIB support :
|
||
|
||
$ make TARGET=linux2628 USE_PCRE=1 USE_OPENSSL=1 USE_ZLIB=1
|
||
|
||
In order to build a 32-bit binary on an x86_64 Linux system with SSL support
|
||
without support for compression but when OpenSSL requires ZLIB anyway :
|
||
|
||
$ make TARGET=linux26 ARCH=i386 USE_OPENSSL=1 ADDLIB=-lz
|
||
|
||
The SSL stack supports session cache synchronization between all running
|
||
processes. This involves some atomic operations and synchronization operations
|
||
which come in multiple flavors depending on the system and architecture :
|
||
|
||
Atomic operations :
|
||
- internal assembler versions for x86/x86_64 architectures
|
||
|
||
- gcc builtins for other architectures. Some architectures might not
|
||
be fully supported or might require a more recent version of gcc.
|
||
If your architecture is not supported, you willy have to either use
|
||
pthread if supported, or to disable the shared cache.
|
||
|
||
- pthread (posix threads). Pthreads are very common but inter-process
|
||
support is not that common, and some older operating systems did not
|
||
report an error when enabling multi-process mode, so they used to
|
||
silently fail, possibly causing crashes. Linux's implementation is
|
||
fine. OpenBSD doesn't support them and doesn't build. FreeBSD 9 builds
|
||
and reports an error at runtime, while certain older versions might
|
||
silently fail. Pthreads are enabled using USE_PTHREAD_PSHARED=1.
|
||
|
||
Synchronization operations :
|
||
- internal spinlock : this mode is OS-independant, light but will not
|
||
scale well to many processes. However, accesses to the session cache
|
||
are rare enough that this mode could certainly always be used. This
|
||
is the default mode.
|
||
|
||
- Futexes, which are Linux-specific highly scalable light weight mutexes
|
||
implemented in user-space with some limited assistance from the kernel.
|
||
This is the default on Linux 2.6 and above and is enabled by passing
|
||
USE_FUTEX=1
|
||
|
||
- pthread (posix threads). See above.
|
||
|
||
If none of these mechanisms is supported by your platform, you may need to
|
||
build with USE_PRIVATE_CACHE=1 to totally disable SSL cache sharing. Then
|
||
it is better not to run SSL on multiple processes.
|
||
|
||
If you need to pass other defines, includes, libraries, etc... then please
|
||
check the Makefile to see which ones will be available in your case, and
|
||
use the USE_* variables in the Makefile.
|
||
|
||
AIX 5.3 is known to work with the generic target. However, for the binary to
|
||
also run on 5.2 or earlier, you need to build with DEFINE="-D_MSGQSUPPORT",
|
||
otherwise __fd_select() will be used while not being present in the libc, but
|
||
this is easily addressed using the "aix52" target. If you get build errors
|
||
because of strange symbols or section mismatches, simply remove -g from
|
||
DEBUG_CFLAGS.
|
||
|
||
You can easily define your own target with the GNU Makefile. Unknown targets
|
||
are processed with no default option except USE_POLL=default. So you can very
|
||
well use that property to define your own set of options. USE_POLL can even be
|
||
disabled by setting USE_POLL="". For example :
|
||
|
||
$ gmake TARGET=tiny USE_POLL="" TARGET_CFLAGS=-fomit-frame-pointer
|
||
|
||
|
||
1.1) DeviceAtlas Device Detection
|
||
---------------------------------
|
||
|
||
In order to add DeviceAtlas Device Detection support, you would need to download
|
||
the API source code from https://deviceatlas.com/deviceatlas-haproxy-module and
|
||
once extracted :
|
||
|
||
$ make TARGET=<target> USE_PCRE=1 USE_DEVICEATLAS=1 DEVICEATLAS_INC=<path to the API root folder> DEVICEATLAS_LIB=<path to the API root folder>
|
||
|
||
These are supported DeviceAtlas directives (see doc/configuration.txt) :
|
||
- deviceatlas-json-file <path to the DeviceAtlas JSON data file>.
|
||
- deviceatlas-log-level <number> (0 to 3, level of information returned by
|
||
the API, 0 by default).
|
||
- deviceatlas-property-separator <character> (character used to separate the
|
||
properties produced by the API, | by default).
|
||
|
||
Sample configuration :
|
||
|
||
global
|
||
deviceatlas-json-file <path to json file>
|
||
|
||
...
|
||
frontend
|
||
bind *:8881
|
||
default_backend servers
|
||
http-request set-header X-DeviceAtlas-Data %[req.fhdr(User-Agent),da-csv(primaryHardwareType,osName,osVersion,browserName,browserVersion)]
|
||
|
||
|
||
1.2) 51Degrees Device Detection
|
||
-------------------------------
|
||
|
||
You can also include 51Degrees for inbuilt device detection enabling attributes
|
||
such as screen size (physical & pixels), supported input methods, release date,
|
||
hardware vendor and model, browser information, and device price among many
|
||
others. Such information can be used to improve the user experience of a web
|
||
site by tailoring the page content, layout and business processes to the
|
||
precise characteristics of the device. Such customisations improve profit by
|
||
making it easier for customers to get to the information or services they
|
||
need. Theses attributes of the device making a web request can be added to HTTP
|
||
headers as configurable parameters.
|
||
|
||
In order to enable 51Degrees get the 51Degrees source code
|
||
(https://github.com/51Degreesmobi/51Degrees-C) and then run make with
|
||
USE_51DEGREES and 51DEGREES_INC and 51DEGREES_SRC set. Make sure to replace
|
||
'51D_REPO_PATH' with the path to the 51Degrees repository.
|
||
|
||
51Degrees provide 2 different detection algorithms.
|
||
|
||
1. Pattern - balances main memory usage and CPU.
|
||
2. Trie - a very high performance detection solution which uses more main
|
||
memory than Pattern.
|
||
|
||
To make with 51Degrees Pattern algorithm use the following command line.
|
||
|
||
$ make TARGET=linux26 USE_51DEGREES=1 51DEGREES_INC='51D_REPO_PATH'/src/pattern 51DEGREES_LIB='51D_REPO_PATH'/src/pattern
|
||
|
||
To use the 51Degrees Trie algorithm use the following command line.
|
||
|
||
$ make TARGET=linux26 USE_51DEGREES=1 51DEGREES_INC='51D_REPO_PATH'/src/trie 51DEGREES_LIB='51D_REPO_PATH'/src/trie
|
||
|
||
A data file containing information about devices, browsers, operating systems
|
||
and their associated signatures is then needed. 51Degrees provide a free
|
||
database with Github repo for this purpose. These free data files are located
|
||
in '51D_REPO_PATH'/data with the extensions .dat for Pattern data and .trie for
|
||
Trie data.
|
||
|
||
The configuration file needs to set the following parameters:
|
||
|
||
51degrees-data-file path to the pattern or trie data file
|
||
51degrees-property-name-list list of 51Degrees properties to detect
|
||
51degrees-property-seperator seperator to use between values
|
||
|
||
The following is an example of the settings for Pattern.
|
||
|
||
51degrees-data-file '51D_REPO_PATH'/data/51Degrees-Lite.dat
|
||
51degrees-property-name-list IsTablet DeviceType IsMobile
|
||
51degrees-property-seperator ,
|
||
|
||
HAProxy needs a way to pass device information to the backend servers. This is
|
||
done by using the 51d converter, which intercepts the User-Agent header and
|
||
creates some new headers. This is controlled in the frontend http-in section
|
||
|
||
The following is an example which adds two new HTTP headers prefixed X-51D-
|
||
|
||
frontend http-in
|
||
bind *:8081
|
||
default_backend servers
|
||
http-request set-header X-51D-DeviceTypeMobileTablet %[req.fhdr(User-Agent),51d(DeviceType,IsMobile,IsTablet)]
|
||
http-request set-header X-51D-Tablet %[req.fhdr(User-Agent),51d(IsTablet)]
|
||
|
||
Here, two headers are created with 51Degrees data, X-51D-DeviceTypeMobileTablet
|
||
and X-51D-Tablet. Any number of headers can be created this way and can be
|
||
named anything. The User-Agent header is passed to the converter in
|
||
req.fhdr(User-Agent). 51d( ) invokes the 51degrees converter. It can be passed
|
||
up to five property names of values to return. Values will be returned in the
|
||
same order, seperated by the 51-degrees-property-seperator configured earlier.
|
||
If a property name can't be found the value 'NoData' is returned instead.
|
||
|
||
The free Lite data file contains information about screen size in pixels and
|
||
whether the device is a mobile. A full list of available properties is located
|
||
on the 51Degrees web site at:
|
||
|
||
https://51degrees.com/resources/property-dictionary.
|
||
|
||
Some properties are only available in the paid for Premium and Enterprise
|
||
versions of 51Degrees. These data sets no only contain more properties but
|
||
are updated weekly and daily and contain signatures for 100,000s of different
|
||
device combinations. For more information see the data options comparison web
|
||
page:
|
||
|
||
https://51degrees.com/compare-data-options
|
||
|
||
|
||
2) How to install it
|
||
--------------------
|
||
|
||
To install haproxy, you can either copy the single resulting binary to the
|
||
place you want, or run :
|
||
|
||
$ sudo make install
|
||
|
||
If you're packaging it for another system, you can specify its root directory
|
||
in the usual DESTDIR variable.
|
||
|
||
|
||
3) How to set it up
|
||
-------------------
|
||
|
||
There is some documentation in the doc/ directory :
|
||
|
||
- architecture.txt : this is the architecture manual. It is quite old and
|
||
does not tell about the nice new features, but it's still a good starting
|
||
point when you know what you want but don't know how to do it.
|
||
|
||
- configuration.txt : this is the configuration manual. It recalls a few
|
||
essential HTTP basic concepts, and details all the configuration file
|
||
syntax (keywords, units). It also describes the log and stats format. It
|
||
is normally always up to date. If you see that something is missing from
|
||
it, please report it as this is a bug. Please note that this file is
|
||
huge and that it's generally more convenient to review Cyril Bont<6E>'s
|
||
HTML translation online here :
|
||
|
||
http://cbonte.github.io/haproxy-dconv/configuration-1.5.html
|
||
|
||
- haproxy-en.txt / haproxy-fr.txt : these are the old outdated docs. You
|
||
should never need them. If you do, then please report what you didn't
|
||
find in the other ones.
|
||
|
||
- gpl.txt / lgpl.txt : the copy of the licenses covering the software. See
|
||
the 'LICENSE' file at the top for more information.
|
||
|
||
- the rest is mainly for developers.
|
||
|
||
There are also a number of nice configuration examples in the "examples"
|
||
directory as well as on several sites and articles on the net which are linked
|
||
to from the haproxy web site.
|
||
|
||
|
||
4) How to report a bug
|
||
----------------------
|
||
|
||
It is possible that from time to time you'll find a bug. A bug is a case where
|
||
what you see is not what is documented. Otherwise it can be a misdesign. If you
|
||
find that something is stupidly design, please discuss it on the list (see the
|
||
"how to contribute" section below). If you feel like you're proceeding right
|
||
and haproxy doesn't obey, then first ask yourself if it is possible that nobody
|
||
before you has even encountered this issue. If it's unlikely, the you probably
|
||
have an issue in your setup. Just in case of doubt, please consult the mailing
|
||
list archives :
|
||
|
||
http://marc.info/?l=haproxy
|
||
|
||
Otherwise, please try to gather the maximum amount of information to help
|
||
reproduce the issue and send that to the mailing list :
|
||
|
||
haproxy@formilux.org
|
||
|
||
Please include your configuration and logs. You can mask your IP addresses and
|
||
passwords, we don't need them. But it's essential that you post your config if
|
||
you want people to guess what is happening.
|
||
|
||
Also, keep in mind that haproxy is designed to NEVER CRASH. If you see it die
|
||
without any reason, then it definitely is a critical bug that must be reported
|
||
and urgently fixed. It has happened a couple of times in the past, essentially
|
||
on development versions running on new architectures. If you think your setup
|
||
is fairly common, then it is possible that the issue is totally unrelated.
|
||
Anyway, if that happens, feel free to contact me directly, as I will give you
|
||
instructions on how to collect a usable core file, and will probably ask for
|
||
other captures that you'll not want to share with the list.
|
||
|
||
|
||
5) How to contribute
|
||
--------------------
|
||
|
||
It is possible that you'll want to add a specific feature to satisfy your needs
|
||
or one of your customers'. Contributions are welcome, however I'm often very
|
||
picky about changes. I will generally reject patches that change massive parts
|
||
of the code, or that touch the core parts without any good reason if those
|
||
changes have not been discussed first.
|
||
|
||
The proper place to discuss your changes is the HAProxy Mailing List. There are
|
||
enough skilled readers to catch hazardous mistakes and to suggest improvements.
|
||
I trust a number of them enough to merge a patch if they say it's OK, so using
|
||
the list is the fastest way to get your code reviewed and merged. You can
|
||
subscribe to it by sending an empty e-mail at the following address :
|
||
|
||
haproxy+subscribe@formilux.org
|
||
|
||
If you have an idea about something to implement, *please* discuss it on the
|
||
list first. It has already happened several times that two persons did the same
|
||
thing simultaneously. This is a waste of time for both of them. It's also very
|
||
common to see some changes rejected because they're done in a way that will
|
||
conflict with future evolutions, or that does not leave a good feeling. It's
|
||
always unpleasant for the person who did the work, and it is unpleasant for me
|
||
too because I value people's time and efforts. That would not happen if these
|
||
were discussed first. There is no problem posting work in progress to the list,
|
||
it happens quite often in fact. Also, don't waste your time with the doc when
|
||
submitting patches for review, only add the doc with the patch you consider
|
||
ready to merge.
|
||
|
||
Another important point concerns code portability. Haproxy requires gcc as the
|
||
C compiler, and may or may not work with other compilers. However it's known
|
||
to build using gcc 2.95 or any later version. As such, it is important to keep
|
||
in mind that certain facilities offered by recent versions must not be used in
|
||
the code :
|
||
|
||
- declarations mixed in the code (requires gcc >= 3.x)
|
||
- GCC builtins without checking for their availability based on version and
|
||
architecture ;
|
||
- assembly code without any alternate portable form for other platforms
|
||
- use of stdbool.h, "bool", "false", "true" : simply use "int", "0", "1"
|
||
- in general, anything which requires C99 (such as declaring variables in
|
||
"for" statements)
|
||
|
||
Since most of these restrictions are just a matter of coding style, it is
|
||
normally not a problem to comply.
|
||
|
||
If your work is very confidential and you can't publicly discuss it, you can
|
||
also mail me directly about it, but your mail may be waiting several days in
|
||
the queue before you get a response.
|
||
|
||
If you'd like a feature to be added but you think you don't have the skills to
|
||
implement it yourself, you should follow these steps :
|
||
|
||
1. discuss the feature on the mailing list. It is possible that someone
|
||
else has already implemented it, or that someone will tell you how to
|
||
proceed without it, or even why not to do it. It is also possible that
|
||
in fact it's quite easy to implement and people will guide you through
|
||
the process. That way you'll finally have YOUR patch merged, providing
|
||
the feature YOU need.
|
||
|
||
2. if you really can't code it yourself after discussing it, then you may
|
||
consider contacting someone to do the job for you. Some people on the
|
||
list might sometimes be OK with trying to do it.
|
||
|
||
Note to contributors: it's very handy when patches comes with a properly
|
||
formated subject. There are 3 criteria of particular importance in any patch :
|
||
|
||
- its nature (is it a fix for a bug, a new feature, an optimization, ...)
|
||
- its importance, which generally reflects the risk of merging/not merging it
|
||
- what area it applies to (eg: http, stats, startup, config, doc, ...)
|
||
|
||
It's important to make these 3 criteria easy to spot in the patch's subject,
|
||
because it's the first (and sometimes the only) thing which is read when
|
||
reviewing patches to find which ones need to be backported to older versions.
|
||
|
||
Specifically, bugs must be clearly easy to spot so that they're never missed.
|
||
Any patch fixing a bug must have the "BUG" tag in its subject. Most common
|
||
patch types include :
|
||
|
||
- BUG fix for a bug. The severity of the bug should also be indicated
|
||
when known. Similarly, if a backport is needed to older versions,
|
||
it should be indicated on the last line of the commit message. If
|
||
the bug has been identified as a regression brought by a specific
|
||
patch or version, this indication will be appreciated too. New
|
||
maintenance releases are generally emitted when a few of these
|
||
patches are merged.
|
||
|
||
- CLEANUP code cleanup, silence of warnings, etc... theorically no impact.
|
||
These patches will rarely be seen in stable branches, though they
|
||
may appear when they remove some annoyance or when they make
|
||
backporting easier. By nature, a cleanup is always minor.
|
||
|
||
- REORG code reorganization. Some blocks may be moved to other places,
|
||
some important checks might be swapped, etc... These changes
|
||
always present a risk of regression. For this reason, they should
|
||
never be mixed with any bug fix nor functional change. Code is
|
||
only moved as-is. Indicating the risk of breakage is highly
|
||
recommended.
|
||
|
||
- BUILD updates or fixes for build issues. Changes to makefiles also fall
|
||
into this category. The risk of breakage should be indicated if
|
||
known. It is also appreciated to indicate what platforms and/or
|
||
configurations were tested after the change.
|
||
|
||
- OPTIM some code was optimised. Sometimes if the regression risk is very
|
||
low and the gains significant, such patches may be merged in the
|
||
stable branch. Depending on the amount of code changed or replaced
|
||
and the level of trust the author has in the change, the risk of
|
||
regression should be indicated.
|
||
|
||
- RELEASE release of a new version (development or stable).
|
||
|
||
- LICENSE licensing updates (may impact distro packagers).
|
||
|
||
|
||
When the patch cannot be categorized, it's best not to put any tag. This is
|
||
commonly the case for new features, which development versions are mostly made
|
||
of.
|
||
|
||
Additionally, the importance of the patch should be indicated when known. A
|
||
single upper-case word is preferred, among :
|
||
|
||
- MINOR minor change, very low risk of impact. It is often the case for
|
||
code additions that don't touch live code. For a bug, it generally
|
||
indicates an annoyance, nothing more.
|
||
|
||
- MEDIUM medium risk, may cause unexpected regressions of low importance or
|
||
which may quickly be discovered. For a bug, it generally indicates
|
||
something odd which requires changing the configuration in an
|
||
undesired way to work around the issue.
|
||
|
||
- MAJOR major risk of hidden regression. This happens when I rearrange
|
||
large parts of code, when I play with timeouts, with variable
|
||
initializations, etc... We should only exceptionally find such
|
||
patches in stable branches. For a bug, it indicates severe
|
||
reliability issues for which workarounds are identified with or
|
||
without performance impacts.
|
||
|
||
- CRITICAL medium-term reliability or security is at risk and workarounds,
|
||
if they exist, might not always be acceptable. An upgrade is
|
||
absolutely required. A maintenance release may be emitted even if
|
||
only one of these bugs are fixed. Note that this tag is only used
|
||
with bugs. Such patches must indicate what is the first version
|
||
affected, and if known, the commit ID which introduced the issue.
|
||
|
||
If this criterion doesn't apply, it's best not to put it. For instance, most
|
||
doc updates and most examples or test files are just added or updated without
|
||
any need to qualify a level of importance.
|
||
|
||
The area the patch applies to is quite important, because some areas are known
|
||
to be similar in older versions, suggesting a backport might be desirable, and
|
||
conversely, some areas are known to be specific to one version. When the tag is
|
||
used alone, uppercase is preferred for readability, otherwise lowercase is fine
|
||
too. The following tags are suggested but not limitative :
|
||
|
||
- doc documentation updates or fixes. No code is affected, no need to
|
||
upgrade. These patches can also be sent right after a new feature,
|
||
to document it.
|
||
|
||
- examples example files. Be careful, sometimes these files are packaged.
|
||
|
||
- tests regression test files. No code is affected, no need to upgrade.
|
||
|
||
- init initialization code, arguments parsing, etc...
|
||
|
||
- config configuration parser, mostly used when adding new config keywords
|
||
|
||
- http the HTTP engine
|
||
|
||
- stats the stats reporting engine as well as the stats socket CLI
|
||
|
||
- checks the health checks engine (eg: when adding new checks)
|
||
|
||
- acl the ACL processing core or some ACLs from other areas
|
||
|
||
- peers the peer synchronization engine
|
||
|
||
- listeners everything related to incoming connection settings
|
||
|
||
- frontend everything related to incoming connection processing
|
||
|
||
- backend everything related to LB algorithms and server farm
|
||
|
||
- session session processing and flags (very sensible, be careful)
|
||
|
||
- server server connection management, queueing
|
||
|
||
- proxy proxy maintenance (start/stop)
|
||
|
||
- log log management
|
||
|
||
- poll any of the pollers
|
||
|
||
- halog the halog sub-component in the contrib directory
|
||
|
||
- contrib any addition to the contrib directory
|
||
|
||
Other names may be invented when more precise indications are meaningful, for
|
||
instance : "cookie" which indicates cookie processing in the HTTP core. Last,
|
||
indicating the name of the affected file is also a good way to quickly spot
|
||
changes. Many commits were already tagged with "stream_sock" or "cfgparse" for
|
||
instance.
|
||
|
||
It is desired that AT LEAST one of the 3 criteria tags is reported in the patch
|
||
subject. Ideally, we would have the 3 most often. The two first criteria should
|
||
be present before a first colon (':'). If both are present, then they should be
|
||
delimited with a slash ('/'). The 3rd criterion (area) should appear next, also
|
||
followed by a colon. Thus, all of the following messages are valid :
|
||
|
||
Examples of messages :
|
||
- DOC: document options forwardfor to logasap
|
||
- DOC/MAJOR: reorganize the whole document and change indenting
|
||
- BUG: stats: connection reset counters must be plain ascii, not HTML
|
||
- BUG/MINOR: stats: connection reset counters must be plain ascii, not HTML
|
||
- MEDIUM: checks: support multi-packet health check responses
|
||
- RELEASE: Released version 1.4.2
|
||
- BUILD: stats: stdint is not present on solaris
|
||
- OPTIM/MINOR: halog: make fgets parse more bytes by blocks
|
||
- REORG/MEDIUM: move syscall redefinition to specific places
|
||
|
||
Please do not use square brackets anymore around the tags, because they give me
|
||
more work when merging patches. By default I'm asking Git to keep them but this
|
||
causes trouble when patches are prefixed with the [PATCH] tag because in order
|
||
not to store it, I have to hand-edit the patches. So as of now, I will ask Git
|
||
to remove whatever is located between square brackets, which implies that any
|
||
subject formatted the old way will have its tag stripped out.
|
||
|
||
In fact, one of the only square bracket tags that still makes sense is '[RFC]'
|
||
at the beginning of the subject, when you're asking for someone to review your
|
||
change before getting it merged. If the patch is OK to be merged, then I can
|
||
merge it as-is and the '[RFC]' tag will automatically be removed. If you don't
|
||
want it to be merged at all, you can simply state it in the message, or use an
|
||
alternate '[WIP]' tag ("work in progress").
|
||
|
||
The tags are not rigid, follow your intuition first, anyway I reserve the right
|
||
to change them when merging the patch. It may happen that a same patch has a
|
||
different tag in two distinct branches. The reason is that a bug in one branch
|
||
may just be a cleanup in the other one because the code cannot be triggered.
|
||
|
||
|
||
For a more efficient interaction between the mainline code and your code, I can
|
||
only strongly encourage you to try the Git version control system :
|
||
|
||
http://git-scm.com/
|
||
|
||
It's very fast, lightweight and lets you undo/redo your work as often as you
|
||
want, without making your mistakes visible to the rest of the world. It will
|
||
definitely help you contribute quality code and take other people's feedback
|
||
in consideration. In order to clone the HAProxy Git repository :
|
||
|
||
$ git clone http://git.haproxy.org/git/haproxy-1.5.git (stable 1.5)
|
||
$ git clone http://git.haproxy.org/git/haproxy.git/ (development)
|
||
|
||
If you decide to use Git for your developments, then your commit messages will
|
||
have the subject line in the format described above, then the whole description
|
||
of your work (mainly why you did it) will be in the body. You can directly send
|
||
your commits to the mailing list, the format is convenient to read and process.
|
||
|
||
-- end
|