# Using roles for creating and managing CloudTrail event context in CloudTrail Event context role Amazon CloudTrail uses Amazon Identity and Access Management (IAM) [service-linked roles](https://docs.amazonaws.cn/IAM/latest/UserGuide/id_roles_terms-and-concepts.html#iam-term-service-linked-role). A service-linked role is a unique type of IAM role that is linked directly to CloudTrail. Service-linked roles are predefined by CloudTrail and include all the permissions that the service requires to call other Amazon services on your behalf. A service-linked role makes setting up CloudTrail easier because you don’t have to manually add the necessary permissions. CloudTrail defines the permissions of its service-linked roles, and unless defined otherwise, only CloudTrail 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 CloudTrail 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](https://docs.amazonaws.cn/IAM/latest/UserGuide/reference_aws-services-that-work-with-iam.html) 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 CloudTrail CloudTrail uses the service-linked role named **AWSServiceRoleForCloudTrailEventContext** – This service linked role is used for managing CloudTrail Event Context and EventBridge rules. The AWSServiceRoleForCloudTrailEventContext service-linked role trusts the following services to assume the role: + `context.cloudtrail.amazonaws.com` The role permissions policy named CloudTrailEventContext allows CloudTrail to complete the following actions on the specified resources: + Actions on resource tags: + `tag:GetResources` + Actions on all Amazon EventBridge resources for the CloudTrail service principal to create rules: + `events:PutRule` + Actions on all Amazon EventBridge resources for the CloudTrail service principal to manage the rules it creates: + `events:PutTargets` + `events:DeleteRule` + `events:RemoveTargets` + `events:RemoveTargets` + Actions on all Amazon EventBridge resources for the CloudTrail service principal to describe the rules it creates: + `events:DescribeRule` + `events:DeRegisterResource` + Actions on all Amazon EventBridge resources: + `events:ListRules` You must configure permissions to allow your users, groups, or roles to create, edit, or delete a service-linked role. For more information, see [Service-linked role permissions](https://docs.amazonaws.cn/IAM/latest/UserGuide/using-service-linked-roles.html#service-linked-role-permissions) in the *IAM User Guide*. For more information about the managed policy associated with AWSServiceRoleForCloudTrailEventContext, see [Amazon managed policies for Amazon CloudTrail](security-iam-awsmanpol.md). ## Creating a service-linked role for CloudTrail You don't need to manually create a service-linked role. When you begin using the context event feature in the Amazon Web Services Management Console, the Amazon CLI, or the Amazon API, CloudTrail 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 recreate the role in your account. When you begin using the context event feature, CloudTrail creates the service-linked role for you again. ## Editing a service-linked role for CloudTrail CloudTrail does not allow you to edit the AWSServiceRoleForCloudTrailEventContext 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](https://docs.amazonaws.cn/IAM/latest/UserGuide/using-service-linked-roles.html#edit-service-linked-role) in the *IAM User Guide*. ## Deleting the AWSServiceRoleForCloudTrailEventContext service-linked role for CloudTrail If you no longer need to use a feature or service that requires the AWSServiceRoleForCloudTrailEventContext 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 by removing the TagContext key from event data stores. **Note** If the CloudTrail 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 delete CloudTrail resources used by the AWSServiceRoleForCloudTrailEventContext service linked role** 1. At the terminal or command line, run the **put-event-configuration** command for the event store from which you want to remove the `TagContext` key. For example, to remove the `TagContext` key from an event store in the *111122223333* account in the US East (Ohio) Region with an ARN of *arn:aws:cloudtrail:us-east-2:111122223333:eventdatastore/a1b2c3d4-5678-90ab-cdef-EXAMPLE11111* where `TagContext` is the only context key selector, you would use the **put-event-configuration** command with no value specified for `--context-key-selectors`: ``` aws cloudtrail put-event-configuration --event-data-store arn:aws:cloudtrail:us-east-2:111122223333:eventdatastore/a1b2c3d4-5678-90ab-cdef-EXAMPLE11111 --max-event-size Large --context-key-selectors ``` 1. Repeat this command for every data store in every Region in the partition. For more information, see [Identify Amazon resources with Amazon Resource Names (ARNs)](https://docs.amazonaws.cn/IAM/latest/UserGuide/reference-arns.html). **To manually delete the service-linked role using IAM** Use the IAM console, the Amazon CLI, or the Amazon API to delete the AWSServiceRoleForCloudTrailEventContext service-linked role. For more information, see [Deleting a service-linked role](https://docs.amazonaws.cn/IAM/latest/UserGuide/using-service-linked-roles.html#delete-service-linked-role) in the *IAM User Guide*.