Overview of managing access permissions to your CloudWatch Logs resources - Amazon CloudWatch Logs

Overview of managing access permissions to your CloudWatch Logs resources

To provide access, add permissions to your users, groups, or roles:

CloudWatch Logs resources and operations

In CloudWatch Logs the primary resources are log groups, log streams 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 type ARN format

Log group

Both of the following are used. The second one, with the :* at the end, is what is returned by the describe-log-groups CLI command and the DescribeLogGroups API.

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

arn:aws:logs:region:account-id:log-group:log_group_name:*

Use the first version, without the trailing :*, in the following situations:

Use the second version, with the trailing :*, to refer to the ARN when specifying permissions in IAM policies for all other API actions.

Log stream

arn:aws:logs:region:account-id:log-group:log_group_name:log-stream:log-stream-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) 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, a 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 a 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 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 cross-Region subscriptions.

Log group permissions and Contributor Insights

Contributor Insights is a feature of CloudWatch that enables you to analyze data from log groups and create time series that display contributor data. You can see metrics about the top-N contributors, the total number of unique contributors, and their usage. For more information, see Using Contributor Insights to Analyze High-Cardinality Data.

When you grant a user the cloudwatch:PutInsightRule and cloudwatch:GetInsightRuleReport permissions, that user can create a rule that evaluates any log group in CloudWatch Logs and then see the results. The results can contain contributor data for those log groups. Be sure to grant these permissions only to users who should be able to view this data.

Resource-based policies

CloudWatch Logs supports resource-based policies for destinations, which you can use to enable cross account subscriptions. For more information, see Step 1: 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. For a list of context keys supported by each AWS service and a list of AWS-wide policy keys, see Actions, resources, and condition keys for AWS services and AWS global condition context keys .

Note

You can use tags to control access to CloudWatch Logs resources, including log groups and destinations. Access to log streams is controlled at the log group level, because of the hierarchical relation between log groups and log streams. For more information about using tags to control access, see Controlling access to Amazon Web Services resources using tags.