AWS CloudFormation Template Generation for Amazon EventBridge Pipes

/ Tutorial

Introduction

Amazon EventBridge is a powerful event bus that allows you to build event-driven architectures. With EventBridge, you can create event rules that trigger actions in other AWS services without writing custom integration code. One of the key functionalities of EventBridge is the ability to create pipes to easily connect different services and orchestrate the flow of events. In this guide, we will explore the AWS CloudFormation template generation feature for EventBridge pipes.

What are EventBridge Pipes?

EventBridge pipes are a way to define and manage the flow of events between different services. With pipes, you can specify a source and a target for your events, and optionally configure various settings such as batching, starting position, and concurrency. This allows you to control how events are processed and ensure they reach the intended destinations efficiently.

Creating a Simple Pipe

Creating a simple pipe using AWS CloudFormation is a breeze. With just a few lines of code, you can define the source and target of your events. An example CloudFormation template for a simple pipe could look like:

“`markdown

AWSTemplateFormatVersion: ‘2010-09-09’
Resources:
MyPipe:
Type: AWS::EventBridge::Pipe
Properties:
Name: MyEventPipe
Source:
Type: S3
Properties:
BucketArn: arn:aws:s3:::my-bucket
Target:
Type: Lambda
Properties:
LambdaFunctionArn: arn:aws:lambda:us-west-2:123456789012:function:my-function
“`

In this example, we are creating a pipe named “MyEventPipe” with a source of an S3 bucket and a target of a Lambda function. This simple configuration will enable the events stored in the S3 bucket to trigger the Lambda function for processing.

Customizing Pipe Settings

While a simple pipe gets the job done in many cases, there are scenarios where you might need more control over the event processing. EventBridge pipes allow you to customize various settings to fine-tune the behavior of the pipe. Let’s explore some of the options available:

Batching

By default, EventBridge pipes process events one by one. However, if you have a high volume of events and want to optimize the performance, you can enable batching. Batching allows you to group multiple events together and process them as a batch, reducing the overhead associated with individual event processing. To enable batching, you can modify the CloudFormation template as follows:

markdown
Target:
Type: Lambda
Properties:
LambdaFunctionArn: arn:aws:lambda:us-west-2:123456789012:function:my-function
BatchSize: 100

In this example, we have set the BatchSize property to 100, which means EventBridge will send events to the Lambda function in batches of 100.

Starting Position

The starting position determines where the pipe should begin processing events from. By default, it starts from the time the pipe is created. However, you can change this behavior by specifying a different starting position. The available options for starting position are:

  • NOW: Start processing events from the current time.
  • TRIM_HORIZON: Start processing events from the oldest available event.
  • AT_TIMESTAMP: Start processing events from a specific timestamp.

To define the starting position in the CloudFormation template, you can use the StartingPosition property:

markdown
Source:
Type: S3
Properties:
BucketArn: arn:aws:s3:::my-bucket
StartingPosition: TRIM_HORIZON

In this example, the pipe will start processing events from the oldest available event in the S3 bucket.

Concurrency

By default, EventBridge processes events from the source and triggers the target asynchronously. However, you have the option to control the concurrency of event processing. Controlling concurrency can be useful when you want to limit the number of events processed simultaneously or ensure a sequential order of processing. To specify the concurrency, you can add the Concurrency property to the CloudFormation template:

markdown
Target:
Type: Lambda
Properties:
LambdaFunctionArn: arn:aws:lambda:us-west-2:123456789012:function:my-function
Concurrency: 10

In this example, the pipe will process events from the source and trigger the Lambda function with a maximum concurrency of 10.

Filtering Events

Sometimes, you might only be interested in processing certain types of events that match specific criteria. EventBridge pipes allow you to define filters to selectively allow events to flow through the pipe. Filters can be based on event attributes, such as the event source, event type, or custom event attributes. To configure filtering in a pipe, you can add the Filter property to the CloudFormation template:

markdown
Source:
Type: S3
Properties:
BucketArn: arn:aws:s3:::my-bucket
Filter:
Type: EventPattern
Properties:
EventSource: aws.s3
EventType: s3:ObjectCreated:*

In this example, the pipe will only allow events with the event source set to aws.s3 and the event type matching the pattern s3:ObjectCreated:* to flow through.

Enriching or Transforming Events

Before the events reach the target, you might want to transform or enrich them to include additional information or modify their structure. EventBridge pipes provide several options for event enrichment and transformation. Let’s explore some of these options:

AWS Lambda

AWS Lambda functions can be integrated into pipes to perform custom transformations or enrichments. You can configure the Lambda function as an enrichment step in the CloudFormation template:

markdown
Enrichment:
Type: AWS::EventBridge::Enrichment
Properties:
LambdaFunctionArn: arn:aws:lambda:us-west-2:123456789012:function:my-enrichment-function

In this example, the events will be sent to the specified Lambda function for enrichment before reaching the target.

AWS Step Functions

AWS Step Functions provide a powerful way to orchestrate complex workflows. EventBridge pipes can leverage Step Functions as an enrichment step in the pipeline. To configure Step Functions as an enrichment step, you can modify the CloudFormation template as follows:

markdown
Enrichment:
Type: AWS::EventBridge::Enrichment
Properties:
StepFunctionsStateMachineArn: arn:aws:states:us-west-2:123456789012:stateMachine:my-state-machine

In this example, the events will be sent to the specified Step Functions state machine for enrichment.

API Destinations

API Destinations in EventBridge allow you to send events to HTTP endpoints, including AWS services and external systems. You can configure an API Destination as an enrichment step in the CloudFormation template:

markdown
Enrichment:
Type: AWS::EventBridge::Enrichment
Properties:
ApiDestinationArn: arn:aws:apigateway:us-west-2:123456789012:/my-api-endpoint

In this example, the events will be sent to the specified API Gateway endpoint for enrichment.

Amazon API Gateway

Amazon API Gateway provides a fully managed service to create, publish, and manage APIs. EventBridge pipes can integrate with API Gateway for event enrichment. To configure API Gateway as an enrichment step, you can modify the CloudFormation template as follows:

markdown
Enrichment:
Type: AWS::EventBridge::Enrichment
Properties:
ApiGatewayRestApiId: my-rest-api-id
ApiGatewayResourceId: my-resource-id

In this example, the events will be sent to the specified API Gateway resource for enrichment.

Conclusion

AWS CloudFormation template generation for Amazon EventBridge pipes simplifies the process of creating and managing event-driven architectures. With just a few lines of code, you can define the flow of events between different services and customize various settings to meet your requirements. Whether you need simple event routing or complex event enrichment, EventBridge pipes and CloudFormation are the perfect combination to streamline your integrations and free up your time to focus on building your services.

Additional Technical Points

  • When creating an EventBridge pipe, you can specify a Dead Letter Queue (DLQ) for the target service to handle failed events.
  • EventBridge pipes support resource-level permissions using AWS Identity and Access Management (IAM) policies.
  • The CloudFormation template for an EventBridge pipe can also include other AWS resources, such as SNS topics, SQS queues, or other Lambda functions.
  • AWS CloudFormation provides the ability to update EventBridge pipes by modifying the template and performing a stack update.
  • You can monitor the performance and health of your EventBridge pipes using CloudWatch metrics and logs.
  • EventBridge pipes can be integrated with AWS Step Functions to build complex event-driven workflows.
  • For event transformation, you can use AWS Lambda to modify the event payload, perform data enrichment, or trigger additional actions based on event contents.
  • EventBridge pipes can be used to create real-time data processing pipelines, event-driven architectures, and serverless data integration solutions.
  • The EventBridge service offers native integrations with a wide range of AWS services, making it easy to connect various components of your application architecture.

References