Using HAProxy to load-balance multiple web servers

Load balancers are used to spread a load among a number of servers. Hardware load balancers are still somewhat expensive, whereas software balancers can achieve most of the benefits of a hardware solution.

HAProxy is the software load balancer of choice for most people: fast, powerful, and highly configurable.

How to do it…

In this recipe, I'll show you how to build an HAProxy server to load-balance web requests across web servers. We'll use exported resources to build the haproxy configuration file just like we did for the NFS example.

1. Create the file modules/haproxy/manifests/master.pp with the following contents:

   class haproxy::master ($app = 'myapp') {
     # The HAProxy master server
     # will collect haproxy::slave resources and add to its balancer
     package { 'haproxy': ensure => installed }
     service { 'haproxy':
       ensure  => running,
       enable  => true,
       require => Package['haproxy'],
     }
   
     include haproxy::config
   
    ...