Boto3 trying to associate an ec2 instance with IAM role works with Name but not arn

Question

so I have been trying to figure out how to attach policies to my EC2 instance such that I can use the SSM functionality. While doing so I tried:

response = ec2_client.associate_iam_instance_profile(
    IamInstanceProfile ={
        'Arn': 'arn:aws:iam::808608558017:role/AmazonSSMRoleForInstancesQuickSetup'
        'Name': 'AmazonSSMRoleForInstancesQuickSetup'
    },
    InstanceId= ID
)

which throws the following error:

ClientError: An error occurred (InvalidParameterValue) when calling the AssociateIamInstanceProfile operation: Value (arn:aws:iam::808608558017:role/AmazonSSMRoleForInstancesQuickSetup) for parameter iamInstanceProfile.arn is invalid. Invalid IAM Instance Profile ARN

I copy-pasted the arn.

but,

response = ec2_client.associate_iam_instance_profile(
    IamInstanceProfile ={
        'Name': 'AmazonSSMRoleForInstancesQuickSetup'
    },
    InstanceId= ID
)

works fine.

documentation for the same seems to suggest that the former should work instead of the latter. I am a little confused about why:)

Answer 1

IAM role ARN ≠ Instance profile ARN, so just use the name is sufficient