Setup and Configure load balancer and proxy using HAProxy

Configure LB and proxy using haproxy

Requirement:
1. One server for load balancer
2. One or two servers for web servers

In my example I have three servers
Load Balancer: master  - 192.168.10.50
Web servers: worker1, worker2 - 192.168.10.51/52

1. On master server, Install haproxy - comes on RedHat DVD
# yum install haproxy
Note: There is no httpd process running on this host.
# rpm -qa httpd

2. Configure haproxy
[root@master ~]# vi /etc/haproxy/haproxy.cfg
do not modify global and default setting,
Directly go to 'frontend main' section
Here, change the port where you want your Load Balancer to run.
I will be using port 8080
I will be disabling firewall and selinux for this lab.
frontend main
    bind *:8080
go all the way down to section called 'backend app,
In this section, you will be adding all web server information.
backend app
    balance     roundrobin
    server w1 192.168.10.51:80 check
    server w2 192.168.10.52:80 check

3. Once config is changed, start the service
# systemctl start haproxy
# systemctl enable haproxy
# systemctl status haproxy

4. Now, go to your web server machines. 
a. In my case, its worker node 1 and node2
Install web server and start the service
# yum install httpd
# systemctl start httpd
# systemctl status httpd
# systemctl enable httpd
# systemctl stop firewalld

b. Create a index file
[root@worker1 html]# cat index.html
This is worker node1
[root@worker2 html]# cat index.html
This is Worker node2

5. Now, get the IP of your load balancer server. 
http://192.168.10.50:8080

You should be able to see the web site. if you refresh, you will see new page.
This proves that load balancer is working.