The code in this repository demonstrates the use of the ‘role and profiles’ Puppet design pattern to configure a pair of active-passive load balancers (using HAProxy and Keepalived) to route traffic to a small cluster of webservers.

The ‘roles and profiles’ design pattern is an abstraction that is used to organise Puppet code. It enables users to glean the information that is most useful to them without a necessarily in-depth knowledge of the Puppet language. It is a bridge between business logic (roles) and the technology needed to deploy it (profiles).

At the business logic level, the loadbalancer_primary and loadbalancer_passive roles were created to represent the active and passive load balancers. These roles grouped together the profiles for each of the following components: firewall, haproxy and keepalived.

The firewall profile ensures that the ports required for nodes to be accessible to the Puppet master and the web remain open. The haproxy profile describes the web server nodes, enables IP forwarding and binds the load balancer to a virtual IP address. The keepalived profiles distinguish between the active and passive load balancers.

This code was tested within the master-agent architecture using 5 Vagrant virtual machines: 1 puppetmaster running Ubuntu 14.04, 2 webserver nodes running Ubuntu 14.04 and 2 loadbalancer nodes running CentOS 6.6.
Puppet version: 3.8.3

To adopt these roles and profiles, the following Puppet modules must be installed
using the puppet module install command:
puppetlabs-apache
puppetlabs-firewall
puppetlabs-haproxy
duritong-sysctl
arioch-keepalived