In some case, people might have started an EC2 instance without giving a proper role and want to give it a role so that the instance would have some new privilege.
From the AWS doc here, it describes the way to attach a new IAM role to a what it calls "existing" instance, I wonder if the "existing" instance actually means a "running" instance? or there is a difference in AWS on "existing" and "running"?
or shall I stop the instance in order to add a new role and restart it after the new role is attached?
Thanks.