Not getting input in scheduled event

Question

I have a lambda which gets triggered by lambda cloudwatch rule. This is the cloudwatch rule created via cloudformation

Resources:
  CloudWatchRule:
    Type: AWS::Events::Rule
    Properties:
      Name: !Sub CloudWatchRule-${Stage}
      Description: "Scheduled event to fetch keys for score generation every hour"
      ScheduleExpression: "rate(2 minutes)"
      Targets:
        - Arn:
            Fn::GetAtt: [FetcherLambda, Arn]
          Id: "CloudWatchEvent"
          Input: '{"hours": 3}'

  CloudWatchRulePermission:
    Type: AWS::Lambda::Permission
    Properties:
      FunctionName:
        Ref: FetcherLambda
      Action: "lambda:InvokeFunction"
      Principal: "events.amazonaws.com"
      SourceArn:
        Fn::GetAtt: [CloudWatchRule, Arn]

I can see in the console that the input is there in Constant(Json) field.

But in the handler, when I am logging I am getting empty event,

public Void handleRequest(final ScheduledEvent scheduledEvent, final Context context) {
        log.info("Received event: {}", scheduledEvent);
        return null;
    }

I am getting a log as Received event: {}

Am I missing something or is there anything else needed to get the input here

user_2860032 · Answer

I believe the issue is that you are using the ScheduledEvent class as your input. When you specify the input from a rule you do not get any of the rest of the schedule data (from AWS::Events::Rule Target - Input):

If you use this property, nothing from the event text itself is passed to the target.

In order to get the data you are expecting you need the class to be something that will be serializable from the input you specify.

Not getting input in scheduled event

1 Answers