Using service-linked roles for Amazon EFS
Amazon Elastic File System uses an Amazon Identity and Access Management (IAM) service-linked role. The Amazon EFS service-linked role is a unique type of IAM role that is linked directly to Amazon EFS. The predefined Amazon EFS service-linked role includes permissions that the service requires to call other Amazon Web Services services on your behalf.
A service-linked role makes setting up Amazon EFS easier because you don't have to manually add the necessary permissions. Amazon EFS defines the permissions of its service-linked role, and only Amazon EFS can assume its role. The defined permissions include the trust policy and the permissions policy, and that permissions policy can't be attached to any other IAM entity.
You can delete the Amazon EFS service-linked role only after first deleting your Amazon EFS file systems. This protects your Amazon EFS resources because you can't inadvertently remove permission to access the resources.
The service-linked role enables all API calls to be visible through Amazon CloudTrail. This helps with monitoring and auditing requirements because you can track all actions that Amazon EFS performs on your behalf. For more information, see Log entries for EFS service-linked roles.
For more information, see Service-linked role permissions in the IAM User Guide.
Service-linked role permissions for Amazon EFS
Amazon EFS uses the service-linked role named AWSServiceRoleForAmazonElasticFileSystem to allow Amazon EFS to call and manage Amazon resources on behalf of your EFS file systems.
The AWSServiceRoleForAmazonElasticFileSystem service-linked role trusts the elasticfilesystem.amazonaws.com to assume
the role.
The role permissions policy allows Amazon EFS to complete the actions included in the policy definition JSON:
{ "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": [ "backup-storage:MountCapsule", "ec2:CreateNetworkInterface", "ec2:DeleteNetworkInterface", "ec2:DescribeSecurityGroups", "ec2:DescribeSubnets", "ec2:DescribeNetworkInterfaceAttribute", "ec2:ModifyNetworkInterfaceAttribute", "tag:GetResources" ], "Resource": "*" }, { "Effect": "Allow", "Action": [ "kms:DescribeKey" ], "Resource": "arn:aws:kms:*:*:key/*" }, { "Effect": "Allow", "Action": [ "backup:CreateBackupVault", "backup:PutBackupVaultAccessPolicy" ], "Resource": [ "arn:aws:backup:*:*:backup-vault:aws/efs/automatic-backup-vault" ] }, { "Effect": "Allow", "Action": [ "backup:CreateBackupPlan", "backup:CreateBackupSelection" ], "Resource": [ "arn:aws:backup:*:*:backup-plan:*" ] }, { "Effect": "Allow", "Action": [ "iam:CreateServiceLinkedRole" ], "Resource": "*", "Condition": { "StringEquals": { "iam:AWSServiceName": [ "backup.amazonaws.com" ] } } }, { "Effect": "Allow", "Action": [ "iam:PassRole" ], "Resource": [ "arn:aws:iam::*:role/aws-service-role/backup.amazonaws.com/AWSServiceRoleForBackup" ], "Condition": { "StringLike": { "iam:PassedToService": "backup.amazonaws.com" } } }, { "Effect": "Allow", "Action": [ "elasticfilesystem:DescribeFileSystems", "elasticfilesystem:CreateReplicationConfiguration", "elasticfilesystem:DescribeReplicationConfigurations", "elasticfilesystem:DeleteReplicationConfiguration", "elasticfilesystem:ReplicationRead", "elasticfilesystem:ReplicationWrite" ], "Resource": "*" } ] }
Note
You must manually configure IAM permissions for Amazon KMS when creating a new EFS file system that is encrypted at rest. To learn more, see Encrypting data at rest.
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 Amazon EFS
In most cases, you don't need to manually create a service-linked role. When you create mount targets or a replication configuration for your EFS file system in the Amazon Web Services Management Console, the Amazon CLI, or the Amazon API, Amazon EFS creates the service-linked role for you.
Additionally, if you manually 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 mount targets or a replication configuration for your EFS file system, Amazon EFS creates the service-linked role for you.
If, however, Amazon EFS does not create the service-linked-role or if you started using Amazon EFS before it supported service-linked roles, then you can manually create the service-linked role. For instructions, see Creating a service-linked role in the IAM User Guide.
Editing a service-linked role for Amazon EFS
Amazon EFS doesn't allow you to edit the AWSServiceRoleForAmazonElasticFileSystem 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 Update
a service-linked role in the IAM User Guide.
Deleting a service-linked role for Amazon EFS
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. For more information, see Clean up resources and protect your Amazon account.
Note
If the Amazon EFS 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.
Use the IAM console, the Amazon CLI, or the Amazon API to delete the AWSServiceRoleForAmazonElasticFileSystem service-linked role. For more information, see Deleting a service-linked role in the IAM User Guide.
Supported Regions for Amazon EFS service-linked roles
Amazon EFS supports using service-linked roles in all of the Amazon Web Services Regions where the service is available. For more information, see Amazon service endpoints in the Amazon Web Services General Reference User Guide.