Step 4: Create a subscription filter - Amazon CloudWatch Logs

Step 4: Create a subscription filter

After you create a destination, the log data recipient account can share the destination ARN (arn:aws:logs:us-east-1:999999999999:destination:testDestination) with other AWS accounts so that they can send log events to the same destination. These other sending accounts users then create a subscription filter on their respective log groups against this destination. The subscription filter immediately starts the flow of real-time log data from the chosen log group to the specified destination.

Note

If you are granting permissions for the subscription filter to an entire organization, you will need to use the ARN of the IAM role that you created in Step 2: (Only if using an organization) Create an IAM role.

In the following example, a subscription filter is created in a sending account. the filter is associated with a log group containing AWS CloudTrail events so that every logged activity made by "Root" AWS credentials is delivered to the destination you previously created. That destination encapsulates a stream called "RecipientStream".

The rest of the steps in the following sections assume that you have followed the directions in Sending CloudTrail Events to CloudWatch Logs in the AWS CloudTrail User Guide and created a log group that contains your CloudTrail events. These steps assume that the name of this log group is CloudTrail/logs.

When you enter the following command, be sure you are signed in as the IAM user or using the IAM role that you added the policy for, in Step 3: Add/validate IAM permissions for the cross-account destination.

aws logs put-subscription-filter \
    --log-group-name "CloudTrail/logs" \
    --filter-name "RecipientStream" \
    --filter-pattern "{$.userIdentity.type = Root}" \
    --destination-arn "arn:aws:logs:region:999999999999:destination:testDestination"

The log group and the destination must be in the same AWS Region. However, the destination can point to an AWS resource such as a Kinesis Data Streams stream that is located in a different Region.