Compile The Nginx Sticky Session Module in CentOS

When managing a few backend servers, it’s occasionally helpful that one customer (program) is constantly served by the same backend server (for session persistance for instance).

Utilizing a persistance by IP (with the ip_hash upstream module) is perhaps not a smart thought in light of the fact that there could be circumstances where a variety of programs are accompanying a similar IP address (behind proxies)and the load balancing system system won’t be reasonable.

Using a cookie to track the upstream server makes each browser unique.

When the sticky module can’t apply, it switchs back to the classic Round Robin Upstream or returns a “Bad Gateway (depending on the no_fallback flag).

Sticky module can’t apply when cookies are not supported by the browser.

Re-Compile Nginx

Include sticky module you will need to re-compile Nginx from source. Modify your compile of Nginx by adding the following directive.

# yum -y install wget tar git gcc make pcre pcre-devel zlib zlib-devel openssl openssl-devel GeoIP GeoIP-devel#
# cd /tmp
# git clone https://github.com/gnosek/nginx-upstream-fair.git
# git clone https://bitbucket.org/nginx-goodies/nginx-sticky-module-ng.git
# git clone https://github.com/yaoweibin/nginx_upstream_check_module.git
# wget http://nginx.org/download/nginx-1.13.5.tar.gz

Untar and Compile Nginx

# tar -xvzf nginx-1.13.5.tar.gz
# cd nginx-1.13.5

# ./configure --prefix=/usr/share/nginx --sbin-path=/usr/sbin/nginx --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --http-client-body-temp-path=/var/lib/nginx/tmp/client_body --http-proxy-temp-path=/var/lib/nginx/tmp/proxy --http-fastcgi-temp-path=/var/lib/nginx/tmp/fastcgi --pid-path=/var/run/nginx.pid --lock-path=/var/lock/subsys/nginx --user=nginx --group=nginx --with-http_gzip_static_module --with-http_stub_status_module --with-http_ssl_module --with-pcre --with-file-aio --with-http_realip_module --without-http_scgi_module --without-http_uwsgi_module --without-http_fastcgi_module --with-http_geoip_module --add-module=/tmp/nginx-sticky-module-ng --add-module=/tmp/nginx_upstream_check_module

# make
# make install

# openssl dhparam -out /etc/nginx/dhparams.pem 2048

Now run below command to make required directory and permissions.

# mkdir /etc/nginx/conf.d 
# mkdir -p /var/lib/nginx/tmp/client_body 
# chown -R nginx.nginx /var/lib/nginx/ 
# chmod -R 770 /var/lib/nginx/

Create init Script

We need to setup the file /etc/init.d/nginx to run when system starts:

This file should be made executable so that we can use it via ‘service nginx:

# chmod +x /etc/init.d/nginx

#!/bin/sh
#
# nginx - this script starts and stops the nginx daemin
#
# chkconfig:   - 85 15
# description:  Nginx is an HTTP(S) server, HTTP(S) reverse \
#               proxy and IMAP/POP3 proxy server
# processname: nginx
# config:      /etc/nginx/nginx.conf
# pidfile:     /var/run/nginx.pid
# user:        nginx

# Source function library.
. /etc/rc.d/init.d/functions

# Source networking configuration.
. /etc/sysconfig/network

# Check that networking is up.
[ "$NETWORKING" = "no" ] && exit 0

nginx="/usr/sbin/nginx"
prog=$(basename $nginx)

NGINX_CONF_FILE="/etc/nginx/nginx.conf"

lockfile=/var/run/nginx.lock

start() {
    [ -x $nginx ] || exit 5
    [ -f $NGINX_CONF_FILE ] || exit 6
    echo -n $"Starting $prog: "
    daemon $nginx -c $NGINX_CONF_FILE
    retval=$?
    echo
    [ $retval -eq 0 ] && touch $lockfile
    return $retval
}

stop() {
    echo -n $"Stopping $prog: "
    killproc $prog -QUIT
    retval=$?
    echo
    [ $retval -eq 0 ] && rm -f $lockfile
    return $retval
}

restart() {
    configtest || return $?
    stop
    start
}

reload() {
    configtest || return $?
    echo -n $"Reloading $prog: "
    killproc $nginx -HUP
    RETVAL=$?
    echo
}

force_reload() {
    restart
}

configtest() {
  $nginx -t -c $NGINX_CONF_FILE
}

rh_status() {
    status $prog
}

rh_status_q() {
    rh_status >/dev/null 2>&1
}

case "$1" in
    start)
        rh_status_q && exit 0
        $1
        ;;
    stop)
        rh_status_q || exit 0
        $1
        ;;
    restart|configtest)
        $1
        ;;
    reload)
        rh_status_q || exit 7
        $1
        ;;
    force-reload)
        force_reload
        ;;
    status)
        rh_status
        ;;
    condrestart|try-restart)
        rh_status_q || exit 0
            ;;
    *)
        echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload|configtest}"
        exit 2
esac

Set the service to start whenever the system boots:

# chkconfig --add nginx
# chkconfig --level 345 nginx on

# service nginx restart

Check Compiled Modules

# nginx -V
nginx version: nginx/1.13.5
built by gcc 4.4.7 20120313 (Red Hat 4.4.7-18) (GCC)
built with OpenSSL 1.0.1e-fips 11 Feb 2013
TLS SNI support enabled
configure arguments: --prefix=/usr/share/nginx --sbin-path=/usr/sbin/nginx --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --http-client-body-temp-path=/var/lib/nginx/tmp/client_body --http-proxy-temp-path=/var/lib/nginx/tmp/proxy --http-fastcgi-temp-path=/var/lib/nginx/tmp/fastcgi --pid-path=/var/run/nginx.pid --lock-path=/var/lock/subsys/nginx --user=nginx --group=nginx --with-http_gzip_static_module --with-http_stub_status_module --with-http_ssl_module --with-pcre --with-file-aio --with-http_realip_module --without-http_scgi_module --without-http_uwsgi_module --without-http_fastcgi_module --with-http_geoip_module --add-module=/tmp/nginx-sticky-module-ng --add-module=/tmp/nginx_upstream_check_module

Usage

upstream {
  sticky;
  server 192.168.0.5:9000;
  server 192.168.0.6:9001;
  server 192.168.0.7:9002;
}

  sticky [name=route] [domain=.foo.bar] [path=/] [expires=1h] 
       [hash=index|md5|sha1] [no_fallback] [secure] [httponly];

Thanks:)