CloudWatch Events¶

This document contains information about the CloudWatch Events service supported in Handel. This Handel service provisions a CloudWatch Events rule, which can then be integrated with services like Lambda to invoke them when events fire.

Important

This service only offers limited tagging support. Cloudwatch events will not be tagged, but the Cloudformation stack used to create them will be. See Tagging Unsupported Resources.

Parameters¶

Parameter	Type	Required	Default	Description
type	string	Yes		This must always be cloudwatchevent for this service type.
description	string	No	Handel-created rule.	The event description.
schedule	string	No		The cron or rate string specifying the schedule on which to fire the event. See the Scheduled Events document for information on the syntax of these schedule expressions.
event_pattern	object	No		The list of event patterns on which to fire the event. In this field you just specify an Event Pattern in YAML syntax.
state	string	No	enabled	What state the rule should be in. Allowed values: ‘enabled’, ‘disabled’
tags	Resource Tags	No		Tags to be applied to the Cloudformation stack which provisions this resource.

Example Handel Files¶

Scheduled Lambda¶

This Handel file shows a CloudWatch Events service being configured, producing to a Lambda on a schedule:

version: 1

name: my-scheduled-lambda

environments:
  dev:
    function:
      type: lambda
      path_to_code: .
      handler: app.handler
      runtime: nodejs6.10
    schedule:
      type: cloudwatchevent
      schedule: rate(1 minute)
      event_consumers:
      - service_name: function
        event_input: '{"some": "param"}'

EBS Events Lambda¶

This Handel file shows a CloudWatch Events service being configured, producing to a Lambda when an EBS volume is created:

version: 1

name: my-event-lambda

environments:
  dev:
    function:
      type: lambda
      path_to_code: .
      handler: app.handler
      runtime: nodejs6.10
    schedule:
      type: cloudwatchevent
      event_pattern:
        source:
        - aws.ec2
        detail-type:
        - EBS Volume Notification
        detail:
        event:
        - createVolume
      event_consumers:
      - service_name: function

Depending on this service¶

The CloudWatch Events service cannot be referenced as a dependency for another Handel service. This service is intended to be used as a producer of events for other services.

Events produced by this service¶

The CloudWatch Events service currently produces events for the following services types:

Lambda

Events consumed by this service¶

The CloudWatch Events service does not consume events from other Handel services.