Lambda Event Source Mapping

AWS Lambda functions can interact with various event sources through Lambda Event Source Mapping Configuration. This feature enables seamless integration between your Lambda functions and AWS services by supporting both push-based and pull-based event sources.

Supported Event Sources

GitMoxi currently supports:

Event Source Type	Supported Services
Push-based	API Gateway, Elastic Load Balancer
Pull-based	All sources supported by the Lambda Event Source Mapping API

Configuration File

Event source mappings are defined in the _lambdaeventsourcedef.json file, which contains configurations for both push and pull event sources.

Push Event Sources

Push event sources automatically invoke Lambda functions based on service-specific triggers, with each service having its own configuration requirements.

Elastic Load Balancer (ELB)

Attribute	Type	Required	Description
Service	string	Yes	Must be elasticloadbalancing.amazonaws.com
TargetGroupArn	string	Yes	ARN of the target group associated with the Lambda function

Example:

{
  "Service": "elasticloadbalancing.amazonaws.com",
  "TargetGroupArn": "<target-group-arn>"
}

API Gateway

Attribute	Type	Required	Description
Service	string	Yes	Must be apigateway.amazonaws.com
ApiId	string	Yes	Unique identifier of the API Gateway instance
RouteId	string	Yes	Identifier for the API’s endpoint or route
AliasStageVariableName	string	No	Name of the stage variable pointing to a specific Lambda alias (useful for versioning deployments)

Example:

{
  "Service": "apigateway.amazonaws.com",
  "ApiId": "<api-id>",
  "RouteId": "<api-route-id>",
  "AliasStageVariableName": "lambdaAlias"
}

Pull Event Sources

Pull event sources use Event Source Mapping to poll the source and invoke the Lambda function with batch processing capabilities.

Configuration Parameters

For pull event sources, use the exact configuration parameters required by the Lambda Event Source Mapping API. GitMoxi passes these parameters directly to the AWS API.

Common parameters include:

Parameter	Description
EventSourceArn	ARN of the event source (e.g., SQS queue, DynamoDB stream)
FunctionName	Name or ARN of the Lambda function
BatchSize	Maximum number of items to retrieve in a single batch
MaximumBatchingWindowInSeconds	Maximum amount of time to gather records before invoking the function

Complete Example

{
  "PushEventSources": [
    {
      "Service": "elasticloadbalancing.amazonaws.com",
      "TargetGroupArn": "<target-group-arn>"
    },
    {
      "Service": "apigateway.amazonaws.com",
      "ApiId": "<api-id>",
      "RouteId": "<api-route-id>",
      "AliasStageVariableName": "lambdaAlias"
    }
  ],
  "PullEventSources": {
    "EventSourceMapping": {
      "EventSourceArn": "<sqs-arn>",
      "FunctionName": "MyLambdaFunction",
      "BatchSize": 10,
      "MaximumBatchingWindowInSeconds": 60
    }
  }
}

Note: Replace placeholder values with your actual resource identifiers when implementing this configuration.