Creating a custom event pattern for an EventBridge rule - AWS CloudFormation

Creating a custom event pattern for an EventBridge rule

You can find several predefined patterns in EventBridge for CloudFormation and Git sync events. This simplifies how an event pattern is created. Instead of writing your own event patterns, you can select field values on a form, and EventBridge generates the pattern for you. You can create a new rule using one of these predefined event patterns or create your own custom event pattern.

When a service like CloudFormation delivers an event to the default event bus, EventBridge uses the event pattern defined in your rule to determine if the event should be delivered to the rule's target(s). An event pattern matches the data in the desired CloudFormation events.

Each event pattern is a JSON object that contains:

  • A source attribute that identifies the service the event is coming from. For example, aws.cloudformation or aws.codeconnections.

  • (Optional): A detail-type attribute that contains an array of the event types to match.

  • (Optional): A detail attribute containing any other event data on which to match.

    For example, the stack ID, the resources involved, status of various resources, and other data relevant to a particular type of events.

For example, the following event pattern matches against all resource status change events:

{
  "source": ["aws.cloudformation"],
  "detail-type": ["CloudFormation Resource Status Change"]
}

While the following event pattern uses event detail data to match only resource status change events where CloudFormation creates a new AWS::S3::Bucket or AWS::SNS::Topic resource:

{
  "source": ["aws.cloudformation"],
  "detail-type": ["CloudFormation Resource Status Change"],
  "detail": {
    "status-details": {
      "status": ["CREATE_COMPLETE"]
    },
    "resource-type": ["AWS::S3::Bucket", "AWS::SNS::Topic"]
  }
}

For more information on writing event patterns, see Event patterns in the Amazon EventBridge User Guide.