Using service-linked roles for Refactor Spaces

AWS Migration Hub Refactor Spaces 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 Refactor Spaces. Service-linked roles are predefined by Refactor Spaces and include all the permissions that the service requires to call other AWS services on your behalf.

A service-linked role makes setting up Refactor Spaces easier because you don’t have to manually add the necessary permissions. Refactor Spaces defines the permissions of its service-linked roles, and unless defined otherwise, only Refactor Spaces 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 Refactor Spaces 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 Role column. Choose a Yes with a link to view the service-linked role documentation for that service.

Service-linked role permissions for Refactor Spaces

Refactor Spaces uses the service-linked role named AWSServiceRoleForMigrationHubRefactorSpaces and associates it with the MigrationHubRefactorSpacesServiceRolePolicy IAM policy – Provides access to AWS resources managed or used by AWS Migration Hub Refactor Spaces.

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

The following is the Amazon Resource Name (ARN) for AWSServiceRoleForMigrationHubRefactorSpaces.

arn:aws:iam::111122223333:role/aws-service-role/refactor-spaces.amazonaws.com/AWSServiceRoleForMigrationHubRefactorSpaces

Refactor Spaces uses the AWSServiceRoleForMigrationHubRefactorSpaces service-linked role when performing cross-account changes. This role must be present in your account to use Refactor Spaces. If it is not present, Refactor Spaces creates it during the following API calls:

You must have iam:CreateServiceLinkedRole permissions to create the service-linked role. If the service-linked role doesn't exist in your account and cannot be created, the Create calls will fail. You must create the service-linked role in the IAM console before using Refactor Spaces, unless you are using the Refactor Spaces console.

Refactor Spaces does not use the service-linked role when making changes in the current signed-in account. For example, when an application is created, Refactor Spaces updates all of the VPCs in the environment so that they can communicate with the newly added VPC. If the VPCs are in other accounts, Refactor Spaces uses the service-linked role and the ec2:CreateRoute permission to update the route tables in other accounts.

To further expand on the create application example, when creating an application, Refactor Spaces updates the route tables that are in the virtual private cloud (VPC) provided in the CreateApplication call. This way, the VPC can communicate with other VPCs in the environment.

The caller must have the ec2:CreateRoute permission that we use to update the route tables. This permission exists in the service-linked role, but Refactor Spaces does not use the service-linked role in the caller’s account to gain this permission. Instead, the caller must have the ec2:CreateRoute permission. Otherwise, the call fails.

You cannot use the service-linked role to escalate your privileges. Your account must already have the permissions in the service-linked role to make the changes in the calling account. The AWSMigrationHubRefactorSpacesFullAccess managed policy, together with a policy that grants the extra required permissions, defines all of the necessary permissions to create Refactor Spaces resources. The service-linked role is a subset of these permissions that is used for specific cross-account calls. For more information about AWSMigrationHubRefactorSpacesFullAccess, see AWS managed policy: AWSMigrationHubRefactorSpacesFullAccess.

Tags

When Refactor Spaces creates resources in your account, they are tagged with the appropriate Refactor Spaces resource ID. For example, the Transit Gateway created from CreateEnvironment is tagged with the refactor-spaces:environment-id tag with the environment ID as the value. The API Gateway API created from CreateApplication is tagged with refactor-spaces:application-id with the application ID as the value. These tags allow Refactor Spaces to manage these resources. If you edit or remove the tags, Refactor Spaces can no longer update or delete the resource.

MigrationHubRefactorSpacesServiceRolePolicy

The role permissions policy named MigrationHubRefactorSpacesServiceRolePolicy allows Refactor Spaces to complete the following actions on the specified resources:

The following is the full policy showing which resources the preceding actions apply to:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeNetworkInterfaces",
                "ec2:DescribeRouteTables",
                "ec2:DescribeSubnets",
                "ec2:DescribeSecurityGroups",
                "ec2:DescribeVpcEndpointServiceConfigurations",
                "ec2:DescribeTransitGatewayVpcAttachments",
                "elasticloadbalancing:DescribeTargetHealth",
                "elasticloadbalancing:DescribeListeners",
                "elasticloadbalancing:DescribeTargetGroups",
                "ram:GetResourceShareAssociations"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:AuthorizeSecurityGroupIngress",
                "ec2:RevokeSecurityGroupIngress",
                "ec2:DeleteSecurityGroup",
                "ec2:DeleteTransitGatewayVpcAttachment",
                "ec2:CreateRoute",
                "ec2:DeleteRoute",
                "ec2:DeleteTags",
                "ram:DeleteResourceShare",
                "ram:AssociateResourceShare",
                "ram:DisassociateResourceShare"
            ],
            "Resource": "*",
            "Condition": {
                "Null": {
                    "aws:ResourceTag/refactor-spaces:environment-id": "false"
                }
            }
        },
        {
            "Effect": "Allow",
            "Action": "ec2:DeleteVpcEndpointServiceConfigurations",
            "Resource": "*",
            "Condition": {
                "Null": {
                    "aws:ResourceTag/refactor-spaces:application-id": "false"
                }
            }
        },
        {
            "Effect": "Allow",
            "Action": [
                "elasticloadbalancing:RegisterTargets",
                "elasticloadbalancing:CreateLoadBalancerListeners",
                "elasticloadbalancing:CreateListener",
                "elasticloadbalancing:DeleteListener",
                "elasticloadbalancing:DeleteTargetGroup"
            ],
            "Resource": "*",
            "Condition": {
                "StringLike": {
                    "aws:ResourceTag/refactor-spaces:route-id": [
                        "*"
                    ]
                }
            }
        },
        {
            "Effect": "Allow",
            "Action": [
                "apigateway:PUT",
                "apigateway:POST",
                "apigateway:GET",
                "apigateway:PATCH",
                "apigateway:DELETE"
            ],
            "Resource": [
                "arn:aws:apigateway:*::/restapis",
                "arn:aws:apigateway:*::/restapis/*",
                "arn:aws:apigateway:*::/vpclinks/*",
                "arn:aws:apigateway:*::/tags",
                "arn:aws:apigateway:*::/tags/*"
            ],
            "Condition": {
                "Null": {
                    "aws:ResourceTag/refactor-spaces:application-id": "false"
                }
            }
        },
        {
            "Effect": "Allow",
            "Action": "apigateway:GET",
            "Resource": "arn:aws:apigateway:*::/vpclinks/*"
        },
        {
            "Effect": "Allow",
            "Action": "elasticloadbalancing:DeleteLoadBalancer",
            "Resource": "arn:*:elasticloadbalancing:*:*:loadbalancer/net/refactor-spaces-nlb-*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "elasticloadbalancing:AddTags",
                "elasticloadbalancing:CreateListener"
            ],
            "Resource": ["arn:*:elasticloadbalancing:*:*:loadbalancer/net/refactor-spaces-nlb-*", "arn:*:elasticloadbalancing:*:*:listener/net/refactor-spaces-nlb-*"],
            "Condition": {
                "Null": {
                    "aws:RequestTag/refactor-spaces:route-id": "false"
                }
            }
        },
        {
            "Effect": "Allow",
            "Action": "elasticloadbalancing:DeleteListener",
            "Resource": "arn:*:elasticloadbalancing:*:*:listener/net/refactor-spaces-nlb-*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "elasticloadbalancing:DeleteTargetGroup",
                "elasticloadbalancing:RegisterTargets"
            ],
            "Resource": "arn:*:elasticloadbalancing:*:*:targetgroup/refactor-spaces-tg-*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "elasticloadbalancing:DeregisterTargets"
            ],
            "Resource": "arn:*:elasticloadbalancing:*:*:targetgroup/refactor-spaces-tg-*",
            "Condition": {
                "Null": {
                    "aws:ResourceTag/refactor-spaces:route-id": "false"
                }
            }
        },
        {
            "Effect": "Allow",
            "Action": [
                "elasticloadbalancing:AddTags",
                "elasticloadbalancing:CreateTargetGroup"
            ],
            "Resource": "arn:*:elasticloadbalancing:*:*:targetgroup/refactor-spaces-tg-*",
            "Condition": {
                "Null": {
                    "aws:RequestTag/refactor-spaces:route-id": "false"
                }
            }
        }
    ]
}

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.

Creating a service-linked role for Refactor Spaces

You don't need to manually create a service-linked role. When you create Refactor Spaces environment, application, service, or route resources in the AWS Management Console, the AWS CLI, or the AWS API, Refactor Spaces creates the service-linked role for you. For more information about creating a service-linked role for Refactor Spaces, see Service-linked role permissions for Refactor Spaces.

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 Refactor Spaces environment, application, service, or route resources, Refactor Spaces creates the service-linked role for you again.

Editing a service-linked role for Refactor Spaces

Refactor Spaces does not allow you to edit the AWSServiceRoleForMigrationHubRefactorSpaces 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.

Deleting a service-linked role for Refactor Spaces

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.

To delete the Refactor Spaces resources used by AWSServiceRoleForMigrationHubRefactorSpaces, use the Refactor Spaces console to delete the resources, or use the delete API operations for the resources. For more information about the delete API operations, see Refactor Spaces API Reference.

To manually delete the service-linked role using IAM

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

Supported Regions for Refactor Spaces service-linked roles

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