Ansible ELB deployment

Ansible playbook to roll a deploy of a java application running on tomcat, on hosts behind AWS ELBs.

Introduction

This ansible playbook rolls updates to a set of application servers behind an Amazon load balancer (ELB).

The steps are:

• Disable alerts on the monitoring system
• Remove the node from the Elastic Load Balancer
• Disable service supervisor (monit)
• Roll the update
• Reverse previous steps to re-enable services

Application deployment

The application deployment is done through a tomcat role, which takes the following steps:

• Undeploy through Tomcat's scripted manager
• Stop tomcat
• Ensure the application cache is removed
• Download the war file from an HTTP repository
• Startup tomcat

TODO List

• Before downloading the file double check md5 to verify if a deployment is necessary
• Implement some sort of wait / app check, as when tomcat startups it ussually takes some time before the application is up and running
• User and password to get the application war should be optional