Terraform is being used to launch the initial cluster, descirbe security groups and more.
Terraform is absolutely essential in order to manage a cluster of this size, knowing the security groups, making sure all the ports are open when you need them and other useful tasks.
Installing on a mac
If you are using a Mac, you can use homebrew to install it.
$ brew install terraform
Installing on other platforms
If you are using any other platorm, just head over to the releases page on Github and grab your executable. https://github.com/hashicorp/terraform/releases
Once you have it installed, we can start really working with our cluster.