Setting up the DynamoDB stream trigger

You must add a trigger to the DynamoDB table created in Setting up the DynamoDB table. This trigger is the key that causes the Lambda function to generate a full IP block list to a static file in the S3 bucket.

The following describes how to create a trigger on a DynamoDB table

1. In DynamoDB, click the table to toggle on its detail window.
2. On the Triggers tab, click Create Trigger, then Existing Lambda function from the dropdown list.
3. From the Function dropdown list, select the Lambda function created in Creating the Lambda function.
4. Leave the Batch size value at its default, which is normally 100.
5. Select the Enable trigger checkbox.
6. Click Create.

At this point, installation is complete, although the AWS CloudWatch and GuardDuty services need additional configuration to work with the Lambda function.