Menu
Amazon CloudWatch Logs
User Guide

Overview of Managing Access Permissions to Your CloudWatch Logs Resources

Every AWS resource is owned by an AWS account, and permissions to create or access a resource are governed by permissions policies. An account administrator can attach permissions policies to IAM identities (that is, users, groups, and roles), and some services (such as AWS Lambda) also support attaching permissions policies to resources.

Note

An account administrator (or administrator user) is a user with administrator privileges. For more information, see IAM Best Practices in the IAM User Guide.

When granting permissions, you decide who is getting the permissions, the resources they get permissions for, and the specific actions that you want to allow on those resources.

CloudWatch Logs Resources and Operations

In CloudWatch Logs the primary resources are log groups and destinations. CloudWatch Logs does not support subresources (other resources for use with the primary resource).

These resources and subresources have unique Amazon Resource Names (ARNs) associated with them as shown in the following table.

Resource TypeARN Format

Log group

arn:aws:logs:region:account-id:log_group_name

Destination

arn:aws:logs:region:account-id:destination:destination_name

For more information about ARNs, see ARNs in IAM User Guide. For information about CloudWatch Logs ARNs, see Amazon Resource Names (ARNs) and AWS Service Namespaces in Amazon Web Services General Reference. For an example of a policy that covers CloudWatch Logs, see Using Identity-Based Policies (IAM Policies) for CloudWatch Logs.

CloudWatch Logs provides a set of operations to work with the CloudWatch Logs resources. For a list of available operations, see CloudWatch Logs Permissions Reference.

Understanding Resource Ownership

The AWS account owns the resources that are created in the account, regardless of who created the resources. Specifically, the resource owner is the AWS account of the principal entity (that is, the root account, an IAM user, or an IAM role) that authenticates the resource creation request. The following examples illustrate how this works:

  • If you use the root account credentials of your AWS account to create a log group, your AWS account is the owner of the CloudWatch Logs resource.

  • If you create an IAM user in your AWS account and grant permissions to create CloudWatch Logs resources to that user, the user can create CloudWatch Logs resources. However, your AWS account, to which the user belongs, owns the CloudWatch Logs resources.

  • If you create an IAM role in your AWS account with permissions to create CloudWatch Logs resources, anyone who can assume the role can create CloudWatch Logs resources. Your AWS account, to which the role belongs, owns the CloudWatch Logs resources.

Managing Access to Resources

A permissions policy describes who has access to what. The following section explains the available options for creating permissions policies.

Note

This section discusses using IAM in the context of CloudWatch Logs. It doesn't provide detailed information about the IAM service. For complete IAM documentation, see What Is IAM? in the IAM User Guide. For information about IAM policy syntax and descriptions, see AWS IAM Policy Reference in the IAM User Guide.

Policies attached to an IAM identity are referred to as identity-based policies (IAM polices) and policies attached to a resource are referred to as resource-based policies. CloudWatch Logs supports identity-based policies, and resource-based policies for destinations, which are used to enable cross account subscriptions. For more information, see Cross-Account Log Data Sharing with Subscriptions.

Identity-Based Policies (IAM Policies)

You can attach policies to IAM identities. For example, you can do the following:

  • Attach a permissions policy to a user or a group in your account – To grant a user permissions to view logs in the CloudWatch Logs, console you can attach a permissions policy to a user or group that the user belongs to.

  • Attach a permissions policy to a role (grant cross-account permissions) – You can attach an identity-based permissions policy to an IAM role to grant cross-account permissions. For example, the administrator in Account A can create a role to grant cross-account permissions to another AWS account (for example, Account B) or an AWS service as follows:

    1. Account A administrator creates an IAM role and attaches a permissions policy to the role that grants permissions on resources in Account A.

    2. Account A administrator attaches a trust policy to the role identifying Account B as the principal who can assume the role.

    3. Account B administrator can then delegate permissions to assume the role to any users in Account B. Doing this allows users in Account B to create or access resources in Account A. The principal in the trust policy an also be an AWS service principal if you want to grant an AWS service permissions to assume the role.

    For more information about using IAM to delegate permissions, see Access Management in the IAM User Guide.

The following is an example policy that grants permissions for the logs:PutLogEvents, logs:CreateLogGroup, and logs:CreateLogStream actions on all resources in us-east-1. For log groups, CloudWatch Logs supports identifying specific resources using the resource ARNs (also referred to as resource-level permissions) for some of the API actions. If you want to include all log groups, you must specify the wildcard character (*).

{
  "Version" : "2012-10-17",
  "Statement" : [
    {
      "Sid" : "",
      "Effect" : "Allow",
      "Principal" : {
        "AWS" : "234567890123"
      },
      "Action" : [
          "logs:PutLogEvents",
          "logs:CreateLogGroup",
          "logs:CreateLogStream",
      "Resource" : "arn:aws:logs:us-east-1:*:*"
    }
  ]
}

For more information about using identity-based policies with CloudWatch Logs, see Using Identity-Based Policies (IAM Policies) for CloudWatch Logs. For more information about users, groups, roles, and permissions, see Identities (Users, Groups, and Roles) in the IAM User Guide.

Resource-Based Policies

CloudWatch Logs supports resource-based policies for destinations, which you can use to enable cross account subscriptions. For more information, see Create a Destination. Destinations can be created using the PutDestination API, and you can add a resource policy to the destination using the PutDestination API. The following example allows another AWS account with the account ID 111122223333 to subscribe their log groups to the destination arn:aws:logs:us-east-1:123456789012:destination:testDestination.

{
  "Version" : "2012-10-17",
  "Statement" : [
    {
      "Sid" : "",
      "Effect" : "Allow",
      "Principal" : {
        "AWS" : "111122223333"
      },
      "Action" : "logs:PutSubscriptionFilter",
      "Resource" : "arn:aws:logs:us-east-1:123456789012:destination:testDestination"
    }
  ]
}

Specifying Policy Elements: Actions, Effects, and Principals

For each CloudWatch Logs resource, the service defines a set of API operations. To grant permissions for these API operations, CloudWatch Logs defines a set of actions that you can specify in a policy. Some API operations can require permissions for more than one action in order to perform the API operation. For more information about resources and API operations, see CloudWatch Logs Resources and Operations and CloudWatch Logs Permissions Reference.

The following are the basic policy elements:

  • Resource – You use an Amazon Resource Name (ARN) to identify the resource that the policy applies to. For more information, see CloudWatch Logs Resources and Operations.

  • Action – You use action keywords to identify resource operations that you want to allow or deny. For example, the logs.DescribeLogGroups permission allows the user permissions to perform the DescribeLogGroups operation.

  • Effect – You specify the effect, either allow or deny, when the user requests the specific action. If you don't explicitly grant access to (allow) a resource, access is implicitly denied. You can also explicitly deny access to a resource, which you might do to make sure that a user cannot access it, even if a different policy grants access.

  • Principal – In identity-based policies (IAM policies), the user that the policy is attached to is the implicit principal. For resource-based policies, you specify the user, account, service, or other entity that you want to receive permissions (applies to resource-based policies only). CloudWatch Logs supports resource-based policies for destinations.

To learn more about IAM policy syntax and descriptions, see AWS IAM Policy Reference in the IAM User Guide.

For a table showing all of the CloudWatch Logs API actions and the resources that they apply to, see CloudWatch Logs Permissions Reference.

Specifying Conditions in a Policy

When you grant permissions, you can use the access policy language to specify the conditions when a policy should take effect. For example, you might want a policy to be applied only after a specific date. For more information about specifying conditions in a policy language, see Condition in the IAM User Guide.

To express conditions, you use predefined condition keys. There are no condition keys specific to CloudWatch Logs. However, there are AWS-wide condition keys that you can use as appropriate. For a complete list of AWS-wide keys, see Available Keys for Conditions in the IAM User Guide.