Using service-linked roles for App Mesh

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

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

For information about other services that support service-linked roles, see Amazon 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 App Mesh

App Mesh uses the service-linked role named AWSServiceRoleForAppMesh – The role allows App Mesh to call Amazon services on your behalf.

The AWSServiceRoleForAppMesh service-linked role trusts the appmesh.amazonaws.com service to assume the role.

Permission details

{
	"Version": "2012-10-17",
	"Statement": [
		{
			"Sid": "CloudMapServiceDiscovery",
			"Effect": "Allow",
			"Action": [
				"servicediscovery:DiscoverInstances",
				"servicediscovery:DiscoverInstancesRevision"
			],
			"Resource": "*"
		},
		{
			"Sid": "ACMCertificateVerification",
			"Effect": "Allow",
			"Action": [
				"acm:DescribeCertificate"
			],
			"Resource": "*"
		}
	]
}

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 App Mesh

If you created a mesh after June 5, 2019 in the Amazon Web Services Management Console, the Amazon CLI, or the Amazon API, App Mesh created the service-linked role for you. For the service-linked role to have been created for you, the IAM account that you used to create the mesh must have had the AWSAppMeshFullAccess IAM policy attached to it, or a policy attached to it that contained the iam:CreateServiceLinkedRole permission. 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 mesh, App Mesh creates the service-linked role for you again. If your account only contains meshes created before June 5, 2019 and you want to use the service-linked role with those meshes, then you can create the role using the IAM console.

You can use the IAM console to create a service-linked role with the App Mesh use case. In the Amazon CLI or the Amazon API, create a service-linked role with the appmesh.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 App Mesh

App Mesh does not allow you to edit the AWSServiceRoleForAppMesh 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 App Mesh

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.

Complete the previous steps for all meshes in your account.

To manually delete the service-linked role using IAM

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

Supported Regions for App Mesh service-linked roles

App Mesh supports using service-linked roles in all of the Regions where the service is available. For more information, see App Mesh Endpoints and Quotas.