Using service-linked IAM roles for DAX

Amazon DynamoDB Accelerator (DAX) 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 DAX. Service-linked roles are predefined by DAX and include all the permissions that the service requires to call other AWS services on your behalf.

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

You can delete the roles only after first deleting their related resources. This protects your DAX 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 in the IAM User Guide. Look for the services that have Yes in the Service-linked roles column. Choose a Yes link to view the service-linked role documentation for that service.

Service-linked role permissions for DAX

DAX uses the service-linked role named AWSServiceRoleForDAX. This role allows DAX to call services on behalf of your DAX cluster.

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

The role permissions policy allows DAX to complete the following actions on the specified resources:

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.

To allow an IAM entity to create AWSServiceRoleForDAX service-linked roles

Add the following policy statement to the permissions for that IAM entity.

{
    "Effect": "Allow",
    "Action": [
        "iam:CreateServiceLinkedRole"
    ],
    "Resource": "*",
    "Condition": {"StringLike": {"iam:AWSServiceName": "dax.amazonaws.com"}}
}

Creating a service-linked role for DAX

You don't need to manually create a service-linked role. When you create a cluster, DAX 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 re-create the role in your account. When you create an instance or a cluster, DAX creates the service-linked role for you again.

Editing a service-linked role for DAX

DAX does not allow you to edit the AWSServiceRoleForDAX 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 DAX

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 all of your DAX clusters before you can delete the service-linked role.

Cleaning up a service-linked role

Before you can use IAM to delete a service-linked role, you must first confirm that the role has no active sessions and remove any resources used by the role.

If you want to remove the AWSServiceRoleForDAX role, you must first delete all of your DAX clusters.

Deleting all of your DAX clusters

Use one of these procedures to delete each of your DAX clusters.

To delete a DAX cluster (AWS CLI)

See delete-cluster in the AWS CLI Command Reference.

To delete a DAX cluster (API)

See DeleteCluster in the Amazon DynamoDB API Reference.

Deleting the service-linked role

To manually delete the service-linked role using IAM

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