I'm confused how to create an IAM role for an ec2 machine and then use it. The error message is super confusing. First I create an IAM role:

machine_role = aws.iam.Role("dockerbuilder-role", ...)

and then I try to create an EC2 instance that uses this role:

server = aws.ec2.Instance('dockerbuilder-pulumi',
    iam_instance_profile=machine_role,
...)

The error message (which annoyingly takes 2 minutes to resolve annoyingly) is

InvalidParameterValue: Value (dockerbuilder-role-908245c) for parameter iamInstanceProfile.name is invalid. Invalid IAM Instance Profile name

. Now if I instantiate the Instance with `

iam_instance_profile="dockerbuilder-role-908245c",

it works. How do I get the name out of the role object to pass into the instance?