principalArn

The ARN of the IAM principal for the AccessEntry. You can specify one ARN for each access entry. You can't specify the same ARN in more than one access entry. This value can't be changed after access entry creation.

The valid principals differ depending on the type of the access entry in the type field. The only valid ARN is IAM roles for the types of access entries for nodes: ````. You can use every IAM principal type for STANDARD access entries. You can't use the STS session principal type with access entries because this is a temporary principal for each session and not a permanent identity that can be assigned permissions.

IAM best practices recommend using IAM roles with temporary credentials, rather than IAM users with long-term credentials.