AWS EMR cluster is not configured with Kerberos authentication

Description

This checks ensure that for EMR cluster using Kerberos, that the kerberos attributes are used and that the realm is set.

Fix - Buildtime

Terraform

• Resource: aws_emr_cluster
• Argument: kerberos_attributes.realm

resource "aws_emr_cluster" "test" {
...
  kerberos_attributes {
    kdc_admin_password                = "somePassword"
+   realm                             = "EC2.INTERNAL"
    }
}