Go ahead and edit content of terraform.tfvars to match your cluster configuration and nodes.
region = "us-west-1"
instance_type = "t2.medium"
keypair_name = "rancher_keypair"
key_file = "~/.ssh/rancher_keypair.pem"
agent_count = "1"
and then run
$ terraform plan
$ terraform apply
When the deployment complete, you can access rancher cluster on http://server_ip:8080. You can see agent hosts under Infrastructure -> Host.
In order to teardown the cluster
$ terraform destroy