Using service-linked roles for Capacity Reservation Fleet

On-Demand Capacity Reservation Fleet uses AWS Identity and Access Management (IAM) service-linked roles. A service-linked role is a unique type of IAM role that is linked directly to Capacity Reservation Fleet. Service-linked roles are predefined by Capacity Reservation Fleet and include all the permissions that the service requires to call other AWS services on your behalf.

A service-linked role makes setting up Capacity Reservation Fleet easier because you don’t have to manually add the necessary permissions. Capacity Reservation Fleet defines the permissions of its service-linked roles, and unless defined otherwise, only Capacity Reservation Fleet can assume its roles. The defined permissions include the trust policy and the permissions policy, and that permissions policy cannot be attached to any other IAM entity.

You can delete a service-linked role only after first deleting their related resources. This protects your Capacity Reservation Fleet resources because you can't inadvertently remove permission to access the resources.

Service-linked role permissions for Capacity Reservation Fleet

Capacity Reservation Fleet uses the service-linked role named AWSServiceRoleForEC2CapacityReservationFleet to create, describe, modify, and cancel Capacity Reservations that were previously created by a Capacity Reservation Fleet, on your behalf.

The AWSServiceRoleForEC2CapacityReservationFleet service-linked role trusts the following entity to assume the role: capacity-reservation-fleet.amazonaws.com.

The role uses the AWSEC2CapacityReservationFleetRolePolicy policy, which includes the following permissions:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeCapacityReservations",
                "ec2:DescribeInstances"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:CreateCapacityReservation",
                "ec2:CancelCapacityReservation",
                "ec2:ModifyCapacityReservation"
            ],
            "Resource": [
                "arn:aws:ec2:*:*:capacity-reservation/*"
            ],
            "Condition": {
                "StringLike": {
                    "ec2:CapacityReservationFleet": "arn:aws:ec2:*:*:capacity-reservation-fleet/crf-*"
                }
            }
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:CreateTags"
            ],
            "Resource": [
                "arn:aws:ec2:*:*:capacity-reservation/*"
            ],
            "Condition": {
                "StringEquals": {
                    "ec2:CreateAction": "CreateCapacityReservation"
                }
            }
        }
    ]
}

You must configure permissions to allow an IAM entity (such as a user, group, or role) to create, edit, or delete a service-linked role. For more information, see Service-Linked Role Permissions in the IAM User Guide.

Create a service-linked role for Capacity Reservation Fleet

You don't need to manually create a service-linked role. When you create a Capacity Reservation Fleet using the create-capacity-reservation-fleet AWS CLI command or the CreateCapacityReservationFleet API, the service-linked role is automatically created for you.

If you delete this service-linked role, and then need to create it again, you can use the same process to recreate the role in your account. When you create a Capacity Reservation Fleet, Capacity Reservation Fleet creates the service-linked role for you again.

Edit a service-linked role for Capacity Reservation Fleet

Capacity Reservation Fleet does not allow you to edit the AWSServiceRoleForEC2CapacityReservationFleet service-linked role. After you create a service-linked role, you cannot change the name of the role because various entities might reference the role. However, you can edit the description of the role using IAM. For more information, see Editing a Service-Linked Role in the IAM User Guide.

Delete a service-linked role for Capacity Reservation Fleet

If you no longer need to use a feature or service that requires a service-linked role, we recommend that you delete that role. That way you don’t have an unused entity that is not actively monitored or maintained. However, you must delete the resources for your service-linked role before you can manually delete it.

Supported Regions for Capacity Reservation Fleet service-linked roles

Capacity Reservation Fleet supports using service-linked roles in all of the Regions where the service is available. For more information, see AWS Regions and Endpoints.