Updating the Stack
In the last chapter, I discussed using CloudFormation and templates to deploy AWS infrastructure as code. You were introduced to the concept of a stack as a collection of infrastructure that is deployed and can be managed as a single entity. You walked through multiple template examples showing how to deploy a very simple template with one AWS resource all the way up to deploying a sample AWS WordPress template that deployed multiple applications on a single EC2 virtual server. In this chapter, I'll cover updating the stack and other management-related items. You'll use two AWS sample templates to see how to update an existing stack to move from being deployed to a single instance to a much more fault-tolerant solution using additional AWS resources and instances in multiple availability zones within a given region.