Cloudwatch alert on AWS Lambda eventsource state

Question

After one of the AWS outage, we found that our application stopped working. On further analysis, we found that trigger to one of our lambda was automatically disabled. The trigger was DynamoDB streams. After we reenabled the trigger ; everything worked fine.

Now my question is , is there any way to configure an alarm that will let us know about the Lambda trigger state changes i.e. whenever lambda trigger state gets disabled we should get an alert.

Is that possible? if yes , Can you please help me out with the metric.

Answer 1

I think it should be possible through Amazon EventBridge (Before CloudWatch Event). With the EventBridge you could setup a rule that will trigger your target (SNS notification, Lambda function) when UpdateEventSourceMapping API call is performed. The rule could have exemplary form of:

{
  "source": [
    "aws.lambda"
  ],
  "detail-type": [
    "AWS API Call via CloudTrail"
  ],
  "detail": {
    "eventSource": [
      "lambda.amazonaws.com"
    ],
    "eventName": [
      "UpdateEventSourceMapping"
    ]
  }
}

For that a CloudTrial trail needs to be setup.