Kernel needs

==============

  Compile a kernel with the following options :

  Kernel/User netlink socket

  LinuxVirtualServer

  Keepalived supports all LVS code.

Library dependencies

====================

  In order to compile Keepalived needs the following libraries :

  * OpenSSL, <www.openssl.org>

Linux flavours

==============

RedHat based systems (RedHat Enterprise/CentOS/Fedora)

------------------------------------------------------

The following build packages are needed:

	make

	autoconf automake (to build from git source tree rather than tarball)

The following libraries need to be installed:

	openssl-devel libnl3-devel ipset-devel iptables-devel libnfnetlink-devel

For magic file identification support:

	file-devel

For SNMP support:

	net-snmp-devel

For DBUS support:

	glib2-devel

For JSON support:

	json-c-devel

For PCRE support

	pcre2-devel

For building the documentation, the following packages need to be installed:

	Fedora: python-sphinx (will pull in: python2-sphinx_rtd_theme)

	CentOS-and-friends: python-sphinx epel-release python-sphinx_rtd_theme

   For latex or pdf files, the following are also needed:

	Fedora: latexmk python-sphinx-latex

	CentOS-and-friends: latexmk texlive texlive-titlesec texlive-framed texlive-threeparttable texlive-wrapfig texlive-multirow

Debian/Ubuntu

-------------

On Debian, install:

	pkg-config

On Ubuntu, install:

	build-essential pkg-config, and to build from git repo automake autoconf

The following libraries need to be installed:

	iptables-dev libipset-dev libnfnetlink-dev libnl-3-dev libnl-genl-3-dev libssl-dev

For magic file identification support:

	libmagic-dev

For SNMP support:

	libsnmp-dev

For DBUS support:

	libglib2.0-dev

For JSON support:

	libjson-c-dev

For PCRE support:

	libpcre2-dev

For building the documentation, the following packages need to be installed:

	python-sphinx python-sphinx-rtd-theme

   For latex or pdf files, the following are also needed:

	texlive-latex-base texlive-generic-extra texlive-latex-recommended texlive-fonts-recommended texlive-latex-extra

Alpine Linux

------------

The following libraries need to be installed:

	iptables-dev ipset-dev libnfnetlink-dev libnl3-dev musl-dev and openssl-dev or libressl-dev

For magic file identification support:

	TBD

For SNMP support:

	net-snmp-dev (requires libressl-dev and not openssl-dev)

For building the documentation, the following packages need to be installed:

	py-sphinx py3-sphinx_rtd_theme

   For latex or pdf files, you'll need texlive or similar, which is not yet

   available as a distro package.

Archlinux

---------

Run the following to install the required libraries:

	pacman -S ipset libnfnetlink libnl1

For magic file identification support:

	TBD

For SNMP support:

	pacman -S net-snmp

for PCRE support:

	pcre-2 (may be installed by default)

For building the documentation, the following packages need to be installed:

	python-sphinx python-sphinx_rtd_theme

   For latex or pdf files, the following are also needed:

	texlive-core texlive-bin texlive-latexextra

Kernel configuration requirements

---------------------------------

The following list is probably incomplete, and will be updated as other

options become known.

BPF

EPOLL

SIGNALFD

TIMERFD

SYSCTL

PROC_FS

INET

IP_MULTICAST

IPV6

IP_VS (unless --disable-lvs is specified)

  IP_VS suboptions to match the real_server/virtual_server configuration

NETFILTER_XTABLES - if strict_mode or no_accept.

  NETFILTER_XT options and IP_SET

IP_ADVANCED_ROUTER and various associated options if static/dynamic routes specified

FIB_RULES if static or dynamic rules are specified

Installing from a git repo

==========================

To install from a git repo, execute:

  1. Ensure you have autoconf and automake installed

  2. git clone http://github.com/acassen/keepalived

  3. cd keepalived

  4. ./build_setup	# generate the autoconf and automake environment

  5. Follow the instructions below for Installation, omitting the first two steps.

Installation

============

  1. tar -xf TARFILE

  2. cd into the directory

  3. './configure'

  4. 'make'

  5. 'make install'. This will install keepalived on your system,

     binaries and configuration file :

     * keepalived : The keepalived daemon program.

     * genhash : The MD5 url digest generator. You need it to

                 configure HTTP GET check and SSL GET check in

                 order to compute MD5SUM digest etalon.

     * /etc/keepalived/keepalived.conf

  6. link keepalived.init into your runlevel directory. On Red Hat systems :

     ln -s /etc/rc.d/init.d/keepalived.init /etc/rc.d/rc3.d/S99keepalived

  By default the configure script uses /usr/local as base directory. You can

  change this value to your own by passing it the --prefix value.

  eg: './configure --prefix=/usr/'

Building RPM files

==================

 If building from tarball:

  1a. tar -xf TARFILE

  1b. cd into the directory

 If building from git clone:

  1. ./build_setup 

 For tarball and git

  2. ./configure

  3. make rpm

 The .rpm files will be created in directory `rpm --eval "%{_rpmdir}"`/ARCH

Modifying source code

=====================

If you modify the source code, especially configure.ac or any Makefile.am

file, you will need to regenerate the build files. Keepalived uses automake

and so you will need to have automake and autoconf installed.

Configuration

=============

  Just take a look at the /etc/keepalived/keepalived.conf file installed.

  It will give you all the information needed. Alternativley, run

  'man keepalived.conf' or look at doc/keepalived.conf.SYNOPSIS.

  If you want more information about keepalived, please refer to the

  keepalived homepage into the documentation section.

  http://www.keepalived.org

Creating a docker container

===========================

There is a very useful github project maintained by osixia for building a

docker container with keepalived.

To use, run the following:

git clone https://github.com/osixia/docker-keepalived.git

cd docker-keepalived

make build

docker run --name keepalived --cap-add=NET_ADMIN --net=host \

  --env KEEPALIVED_INTERFACE=eth0 -d osixia/keepalived:1.3.5 \

	# or whatever version of keepalived you have

To update the keepalived source code, put a new tarball in the image

directory (the Dockerfile may need updating with a new version).

Useful docker commands are:

docker logs keepalvied 2>&1 | lessa	# view system logs of container

docker exec it keepalived bash		# execute shell in container

docker rm -f keepalived			# Remove the container

keepalived is unable to load the ip_tables, ip6_tables, xt_set and ip_vs

modules from within the container, so ensure they are already loaded in

the host system.

To generate a core file in the root filesystem of the container,

/proc/sys/kernel/core_pattern needs to be updated in the host system,

and not from the container (or in other words the -M option to keepalived

does not work within a container. Installing gdb in the container (edit

the image/Dockerfile to add it before make build) may be helpful if you

need to examine core files in the container.

Have fun with it !

Alexandre, <acassen@linux-vs.org>