Using HAProxy to load-balance multiple web servers

Once upon a time a load balancer was a big box that sat in a rack and cost eighty thousand dollars. Although you can still buy those, for most organizations a software load balancer solution using commodity Linux servers is a better value proposition.

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 two existing backend servers.

1. Run the following commands:

   ubuntu@cookbook:~/puppet$ mkdir -p modules/haproxy/manifests
   ubuntu@cookbook:~/puppet$ mkdir -p modules/haproxy/files
   

2. Create the file modules/haproxy/manifests/init.pp with the following contents:

   # Manage HAProxy
   class haproxy {
     package { 'haproxy': ensure => installed }
   
     file { '/etc/default/haproxy':
       content => "ENABLED=1\n",
       require => Package['haproxy'],
     }
   
     service { 'haproxy':
       ensure  =>...