Cloudformation and Roles... but mostly roles

I'm fairly new to AWS I created a role and now I've found I need another. Is there away to join multiple roles to make another or do I have to just build something new ?

Resources:
  ECROLE:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - ec2.amazonaws.com
            Action:
              - sts:AssumeRole
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/AmazonEC2ContainerRegistryPowerUser

  EXTRAROLE:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
          Service:
            - ec2.amazonaws.com
        Action:
          - sts:AssumeRole
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/AmazonEC2ContainerRegistryReadOnly

  ECROLEINSTANCEPROFILE:
    Type: "AWS::IAM::InstanceProfile"
    Properties:
      Path: /
      Roles:
        - !Ref ECROLE
 I'd like to just add something here ...          - !Ref EXTRAROLE
      InstanceProfileName: ECROLEINSTANCEPROFILE

Outputs:
  ECROLEKEY:
   Description: Role to be used for interacting with ECR.
   Value: !Ref ECROLE
   Export:
    Name: ECROLEOUTPUT

In the AWS::IAM::InstanceProfile" stanza I've put the kind of thing I was thinking ...

Thanks

Solution

The Roles property in AWS::IAM::InstanceProfile is currently limited to exactly 1 Role (see AWS::IAM::InstanceProfile Roles.

Creating a new Role is going to be your best bet.

If you find that you are sharing permissions between a number of different roles, then creating reusable Managed Policies will help with that. That said, in your example, you're already using existing managed policies.