To clamp down the network access, the first thing that needs to be done is to create an Amazon VPC. This requires a fair bit of understanding of networking concepts, which are beyond the scope of this book. Long story short: we will provide an infrastructure as described here, that is, a VPC with two subnets, public and private, with a NAT Gateway.
Creating and setting up a VPC in the proper way is an elaborate task better done by an orchestration tool. We will have a look at how it is done in Chapter 8, Scale Your Application.
