Using service-linked roles for Amazon S3 on Outposts

Amazon S3 on Outposts 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 S3 on Outposts. Service-linked roles are predefined by S3 on Outposts and include all the permissions that the service requires to call other AWS services on your behalf.

A service-linked role makes setting up S3 on Outposts easier because you don’t have to manually add the necessary permissions. S3 on Outposts defines the permissions of its service-linked roles, and unless defined otherwise, only S3 on Outposts 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 S3 on Outposts resources because you can't inadvertently remove permission to access the resources.

For information about other services that support service-linked roles, see AWS Services That Work with IAM and look for the services that have Yes in the Service-linked roles column. Choose a Yes with a link to view the service-linked role documentation for that service.

Service-linked role permissions for S3 on Outposts

S3 on Outposts uses the service-linked role named AWSServiceRoleForS3OnOutposts to help manage network resources for you.

The AWSServiceRoleForS3OnOutposts service-linked role trusts the following services to assume the role:

• s3-outposts.amazonaws.com

The role permissions policy named AWSS3OnOutpostsServiceRolePolicy allows S3 on Outposts to complete the following actions on the specified resources:

{
    "Version": "2012-10-17",
    "Statement": [{
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeSubnets",
                "ec2:DescribeSecurityGroups",
                "ec2:DescribeNetworkInterfaces",
                "ec2:DescribeVpcs",
                "ec2:DescribeCoipPools",
                "ec2:GetCoipPoolUsage",
                "ec2:DescribeAddresses",
                "ec2:DescribeLocalGatewayRouteTableVpcAssociations"
            ],
            "Resource": "*",
            "Sid": "DescribeVpcResources"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:CreateNetworkInterface"
            ],
            "Resource": [
                "arn:aws:ec2:*:*:subnet/*",
                "arn:aws:ec2:*:*:security-group/*"
            ],
            "Sid": "CreateNetworkInterface"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:CreateNetworkInterface"
            ],
            "Resource": [
                "arn:aws:ec2:*:*:network-interface/*"
            ],
            "Condition": {
                "StringEquals": {
                    "aws:RequestTag/CreatedBy": "S3 On Outposts"
                }
            },
            "Sid": "CreateTagsForCreateNetworkInterface"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:AllocateAddress"
            ],
            "Resource": [
                "arn:aws:ec2:*:*:ipv4pool-ec2/*"
            ],
            "Sid": "AllocateIpAddress"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:AllocateAddress"
            ],
            "Resource": [
                "arn:aws:ec2:*:*:elastic-ip/*"
            ],
            "Condition": {
                "StringEquals": {
                    "aws:RequestTag/CreatedBy": "S3 On Outposts"
                }
            },
            "Sid": "CreateTagsForAllocateIpAddress"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:ModifyNetworkInterfaceAttribute",
                "ec2:CreateNetworkInterfacePermission",
                "ec2:DeleteNetworkInterface",
                "ec2:DeleteNetworkInterfacePermission",
                "ec2:DisassociateAddress",
                "ec2:ReleaseAddress",
                "ec2:AssociateAddress"
            ],
            "Resource": "*",
            "Condition": {
                "StringEquals": {
                    "aws:ResourceTag/CreatedBy": "S3 On Outposts"
                }
            },
            "Sid": "ReleaseVpcResources"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:CreateTags"
            ],
            "Resource": "*",
            "Condition": {
                "StringEquals": {
                    "ec2:CreateAction": [
                        "CreateNetworkInterface",
                        "AllocateAddress"
                    ],
                    "aws:RequestTag/CreatedBy": [
                        "S3 On Outposts"
                    ]
                }
            },
            "Sid": "CreateTags"
        }
    ]
}

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

Creating a service-linked role for S3 on Outposts

You don't need to manually create a service-linked role. When you create an S3 on Outposts endpoint in the AWS Management Console, the AWS CLI, or the AWS API, S3 on Outposts creates the service-linked role 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 an S3 on Outposts endpoint, S3 on Outposts creates the service-linked role for you again.

You can also use the IAM console to create a service-linked role with the S3 on Outposts use case. In the AWS CLI or the AWS API, create a service-linked role with the s3-outposts.amazonaws.com service name. For more information, see Creating a service-linked role in the IAM User Guide. If you delete this service-linked role, you can use this same process to create the role again.

Editing a service-linked role for S3 on Outposts

S3 on Outposts does not allow you to edit the AWSServiceRoleForS3OnOutposts service-linked role. This includes the name of the role because various entities might reference it. 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.

Deleting a service-linked role for S3 on Outposts

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 clean up the resources for your service-linked role before you can manually delete it.

Note

If the S3 on Outposts service is using the role when you try to delete the resources, then the deletion might fail. If that happens, wait for a few minutes and try the operation again.

To delete S3 on Outposts resources used by the AWSServiceRoleForS3OnOutposts role

1. Delete the S3 on Outposts endpoints in your AWS account across all AWS Regions.

2. Delete the service-linked role using IAM.

   Use the IAM console, the AWS CLI, or the AWS API to delete the AWSServiceRoleForS3OnOutposts service-linked role. For more information, see Deleting a service-linked role in the IAM User Guide.

Supported Regions for S3 on Outposts service-linked roles

S3 on Outposts supports using service-linked roles in all of the AWS Regions where the service is available. For more information, see S3 on Outposts Regions and endpoints.