{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Metadata": {},
  "Parameters": {},
  "Rules": {},
  "Mappings": {},
  "Conditions": {},
  "Resources": {
    "MyRole": {
      "Type": "AWS::IAM::Role",
      "Properties": {
        "AssumeRolePolicyDocument": {
          "Statement": [
            {
              "Effect": "Allow",
              "Action": "sts:AssumeRole",
              "Principal": {
                "AWS": [
                  "123456789012",
                  "arn:aws:iam::123456789012:root",
                  {
                    "Fn::Sub": "arn:aws:iam::${AWS::AccountId}:root"
                  }
                ]
              }
            }
          ]
        }
      }
    }
  },
  "Outputs": {}
}