I am using the "aws ec2 run-instances" command (from the awscli package) to launch an instance in AWS EC2. I want to set an IAM role on the instance I am launching. The IAM role is configured and I can use it successfully when launching an instance from the AWS web UI. But when I try to do this using that command, and the "--iam-instance-profile" option, it failed. Doing "aws ec2 run-instances help" shows Arn= and Name= subfields for the value. When I try to look up the Arn using "aws iam list-instance-profiles" it gives this error message:

A client error (AccessDenied) occurred: User: arn:aws:sts::xxxxxxxxxxxx:assumed-role/shell/i-15c2766d is not authorized to perform: iam:ListInstanceProfiles on resource: arn:aws:iam::xxxxxxxxxxxx:instance-profile/

(where xxxxxxxxxxxx is my AWS 12-digit account number)

I looked up the Arn string via the web UI and used that via "--iam-instance-profile Arn=arn:aws:iam::xxxxxxxxxxxx:instance-profile/shell" on the run-instances command, and that failed with:

A client error (UnauthorizedOperation) occurred: You are not authorized to perform this operation.

If I leave off the "--iam-instance-profile" option entirely, the instance will launch but it will not have the IAM role setting I need. So the permission seems to have something to do with using "--iam-instance-profile" or accessing IAM data. I repeated several times in case of AWS glitches (they happen sometimes) and no success.

I suspected that perhaps there is a restriction that an instance with an IAM role is not allowed to launch an instance with a more powerful IAM role. But in this case, the instance I am doing the command in has the same IAM role that I am trying to use. named "shell" (though I also tried using another one, no luck).

• Is setting an IAM role not even permitted from an instance (via its IAM role credentials)?

• Is there some higher IAM role permission needed to use IAM roles, than is needed for just launching a plain instance?

• Is "--iam-instance-profile" the appropriate way to specify an IAM role?

• Do I need to use a subset of the Arn string, or format it in some other way?

• Is it possible to set up an IAM role that can do any IAM role accesses (maybe a "Super Root IAM" ... making up this name)?

FYI, everything involves Linux running on the instances. Also, I am running all this from an instance because I could not get these tools installed on my desktop. That and I do not want to put my IAM user credentials on any AWS storage as advised by AWS here.

after answered:

I did not mention the launching instance permission of "PowerUserAccess" (vs. "AdministratorAccess") because I did not realize additional access was needed at the time the question was asked. I assumed that the IAM role was "information" attached to the launch. But it really is more than that. It is a granting of permission.