Using service-linked roles for Amazon ECS
Amazon Elastic Container Service 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 Amazon ECS. The service-linked role is predefined by Amazon ECS and includes all the permissions that the service requires to call other Amazon services on your behalf.
A service-linked role makes setting up Amazon ECS easier because you don’t have to manually add the necessary permissions. Amazon ECS defines the permissions of its service-linked roles, and unless defined otherwise, only Amazon ECS 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.
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 roles column. Choose a Yes with a link to view the service-linked role documentation for that service.
Service-linked role permissions for Amazon ECS
Amazon ECS uses the service-linked role named AWSServiceRoleForECS.
The AWSServiceRoleForECS service-linked role trusts the following services to assume the role:
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ecs.amazonaws.com
The role permissions policy named AmazonECSServiceRolePolicy allows Amazon ECS to complete the following actions on the specified resources:
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Action: When using the
awsvpc
network mode for your Amazon ECS tasks, Amazon ECS manages the lifecycle of the elastic network interfaces associated with the task. This also includes tags that Amazon ECS adds to your elastic network interfaces. -
Action: When using a load balancer with your Amazon ECS service, Amazon ECS manages the registration and deregistration of resources with the load balancer.
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Action: When using Amazon ECS service discovery, Amazon ECS manages the required Route 53 and Amazon Cloud Map resources for service discovery to work.
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Action: When using Amazon ECS service auto scaling, Amazon ECS manages the required Auto Scaling resources.
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Action: Amazon ECS creates and manages CloudWatch alarms and log streams that assist in the monitoring of your Amazon ECS resources.
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Action: When using Amazon ECS Exec, Amazon ECS manages the permissions needed to start Amazon ECS Exec sessions to your tasks.
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Action: When using Amazon ECS Service Connect, Amazon ECS manages the required Amazon Cloud Map resources to use the feature.
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Action: When using Amazon ECS capacity providers, Amazon ECS manages the permissions required to modify the Auto Scaling group and its Amazon EC2 instances.
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 ECS
In most cases you don't need to manually create a service-linked role. When you create a cluster or create or update a service in the Amazon Web Services Management Console, the Amazon CLI, or the Amazon API, Amazon ECS creates the service-linked role for you. If you do not see the AWSServiceRoleForECS role after you create a cluster, perform the following to fix the issue:
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Verify and configure the permissions to allow Amazon ECS to create, edit, or delete a service-linked role on your behalf. For more information, see Service-linked role permissions in the IAM User Guide.
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Retry the cluster creation operation, or manually create the service-linked role.
You can use the IAM console to create the AWSServiceRoleForECS service-linked role. In the Amazon CLI or the Amazon API, create a service-linked role with the
ecs.amazonaws.com
service name. For more information, see Creating a service-linked role in the IAM User Guide.
Important
This service-linked role can appear in your account if you completed an action in another service that uses the features supported by this role.
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 cluster or create or update a service, Amazon ECS creates the service-linked role for you again.
If you delete this service-linked role, you can use the same IAM process to create the role again.
Editing a service-linked role for Amazon ECS
Amazon ECS doesn't allow you to edit the AWSServiceRoleForECS 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 ECS
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 Amazon ECS 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 check whether the service-linked role has an active session
Open the IAM console at https://console.amazonaws.cn/iam/
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In the navigation pane, choose Roles and choose the AWSServiceRoleForECS name (not the check box).
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On the Summary page, choose Access Advisor and review recent activity for the service-linked role.
Note
If you are unsure whether Amazon ECS is using the AWSServiceRoleForECS role, you can try to delete the role. If the service is using the role, then the deletion fails and you can view the regions where the role is being used. If the role is being used, then you must wait for the session to end before you can delete the role. You cannot revoke the session for a service-linked role.
To remove Amazon ECS resources used by the AWSServiceRoleForECS service-linked role
You must delete all Amazon ECS clusters in all Amazon Regions before you can delete the AWSServiceRoleForECS role.
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Scale all Amazon ECS services down to a desired count of 0 in all regions, and then delete the services. For more information, see Updating an Amazon ECS service using the console and Deleting an Amazon ECS service using the console.
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Force deregister all container instances from all clusters in all regions. For more information, see Deregistering an Amazon ECS container instance.
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Delete all Amazon ECS clusters in all regions. For more information, see Deleting an Amazon ECS cluster.
To manually delete the service-linked role using IAM
Use the IAM console, the Amazon CLI, or the Amazon API to delete the AWSServiceRoleForECS service-linked role. For more information, see Deleting a service-linked role in the IAM User Guide.
Supported regions for Amazon ECS service-linked roles
Amazon ECS supports using service-linked roles in all of the regions where the service is available. For more information, see Amazon regions and endpoints.