Default IAM role for AWS Glue

When you create an ETL Job you have to define which role to use. Ensure your trust policy on the Role is as follows for it to appear in the list of available roles

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "Service": "glue.amazonaws.com"
            },
            "Action": [
                "sts:TagSession",
                "sts:AssumeRole"
            ]
        }
    ]
}