state_machine_input = {
            'STATE_MACHINE_DEFINITION_NAME': event_dict.get('workflowToBeTriggered'),
            'LDAP_USER': event_dict.get('updatedBy')
        }
        eventbridge_client = boto3.client('events')

        response = eventbridge_client.put_targets(
            Rule=f"{EVENT_NAMING_SUFFIX}{event_dict.get('name')}",
            Targets=[
                {
                    'Id': SM_INITIATION_LAMBDA_FUNCTION_NAME,
                    'Arn': SM_INITIATION_LAMBDA_FUNCTION_ARN,
                    'Input': json.dumps(state_machine_input, indent=2)
                }
            ]
        )

I am creating an eventbridge rule to trigger a lambda, and i need to pass constant input to the target. this part is my problem: 'Input': json.dumps(state_machine_input, indent=2) that is not working on the eventbridge. the rule is being created with the Target input but it is not working.

if i remove the indent=2, and then i manually click the prettify on the aws console eventbridge, then it works.

I already tried adding these separators=(',', ':'), ensure_ascii=False nothing works. only the prettify button.

which i cant do in production, it should be working already upon deployment without manual intervention.

prettify button

        state_machine_input = {
            'STATE_MACHINE_DEFINITION_NAME': event_dict.get('workflowToBeTriggered'),
            'LDAP_USER': event_dict.get('updatedBy')
        }
        eventbridge_client = boto3.client('events')

        response = eventbridge_client.put_targets(
            Rule=f"{EVENT_NAMING_SUFFIX}{event_dict.get('name')}",
            Targets=[
                {
                    'Id': SM_INITIATION_LAMBDA_FUNCTION_NAME,
                    'Arn': SM_INITIATION_LAMBDA_FUNCTION_ARN,
                    'Input': json.dumps(state_machine_input, indent=2)
                }
            ]
        )

I am creating an eventbridge rule to trigger a lambda, and i need to pass constant input to the target. this part is my problem: 'Input': json.dumps(state_machine_input, indent=2) that is not working on the eventbridge. the rule is being created with the Target input but it is not working.

if i remove the indent=2, and then i manually click the prettify on the aws console eventbridge, then it works.

I already tried adding these separators=(',', ':'), ensure_ascii=False nothing works. only the prettify button.

which i cant do in production, it should be working already upon deployment without manual intervention.

prettify button

• boto3
• aws-event-bridge

2 Answers 2

The issue is likely due to extra whitespaces or formatting introduced by the indent=2 argument when serializing the JSON using json.dumps

Turns out the issue is easy to fix. I needed to add permission to invoke the lambda by the specific rule. It only confuses me because of the fact that the prettify button will do the work which is nice but not actually the reason why its working. It is working whenever i made any changes and save it via the aws console, that way the eventbridge is smart enough to add the necessary permission to make it. But if you create the rule via a lambda(boto3) it will not automatically add that permission.