What should I change to run it?

First, you need to spin up 2 EC2 instances and assign a secondary IP address to one of them.

Then change the following variables inside defaults:

# private IP addresses of ec2 instances
master_ip_address:
slave_ip_address:

VIP:  # instance's secondary IP address
VIP_subnet: 20 # CIDR netmask of a subnet the VIP belongs to

You'll also need to change variables in var/main.yml:

aws_access_key:
aws_secret_key:
region:

But before you do this, create an IAM user with appropriate access policy. You can create a custom policy using contents of aws_policy_example file in this repo, then attach this policy to a new user.

Of course, don't forget to change the path to your private key in ansible.cfg:

private_key_file = ~/.ssh/express42

and change IP address of freeradius host in hosts file.

How to run?

You can use the following command:

ansible-playbook site.yml