Configuring EventBridge to send notifications based on a particular event pattern

Amazon EventBridge is a serverless event bus service that facilitates event-driven application architectures by using events generated from your apps, services, and resources. For AWS Certified DevOps Engineer – Professional (DOP-C02) candidates, understanding how to configure EventBridge to send notifications based on specific event patterns is essential. In this post, we’ll cover the steps to configure EventBridge for this purpose, and where applicable, we will illustrate with examples.

Step 1: Define Event Pattern

The first step is to define an event pattern that matches the events of interest. Event patterns in EventBridge are expressed in JSON and can filter events by various dimensions such as source, detail-type, and specific data within the event itself.

Example Event Pattern:

Suppose you want to receive notifications for any AWS EC2 instance state-change notifications. You define an event pattern like the following:

{
“source”: [“aws.ec2”],
“detail-type”: [“EC2 Instance State-change Notification”],
“detail”: {
“state”: [“running”, “stopped”]
}
}

This event pattern filters events from the aws.ec2 source that are of the EC2 Instance State-change Notification detail-type, specifically for instances that transition to the running or stopped state.

Step 2: Create a Rule

1. Navigate to the Amazon EventBridge console.
2. In the navigation pane, select “Rules”, then click “Create rule”.
3. Enter a name and description for your rule.
4. For “Define pattern”, select “Event pattern”, and choose “Custom pattern”.
5. Paste your predefined event pattern JSON in the provided text box.
6. Click “Next”.

Example Rule Name:

EC2InstanceStateChange

Step 3: Select Targets

1. In “Select targets”, choose your target service. For example, for SNS notifications, select “SNS topic”.
2. Specify the SNS topic ARN you want to use, or create a new topic.
3. If necessary, configure input transformation to format the event data.
4. Click “Next”.

Example SNS Topic ARN:

arn:aws:sns:us-west-2:123456789012:MyNotificationTopic

Step 4: Configure Rule Details and Create

1. Review the details you’ve provided.
2. Optionally, add tags.
3. Confirm the rule is set to be enabled.
4. Click “Create”.

Now, whenever the specified event pattern is matched by an event in the AWS environment, Amazon EventBridge will trigger the configured rule and notify the designated target.

To illustrate with an example, let’s consider the following scenario: You’re running a fleet of EC2 instances and want to be notified whenever an instance stops or starts. After setting up the EventBridge rule as described, notifications will be sent to the specified SNS topic every time an EC2 instance changes to the running or stopped states. You can then subscribe an email address or an SMS number to this SNS topic to receive these notifications.

EventBridge Best Practices

• Rule Naming Conventions: Use meaningful names that reflect the purpose of the rule.
• Limit and Paginate: Be mindful of limits such as the number of rules per event bus, and paginate through results if necessary.
• Permission Management: Grant only required permissions using AWS Identity and Access Management (IAM) roles and policies.
• Testing and Troubleshooting: Always test your event patterns and rule configurations in a staging environment before deploying to production.

It’s imperative for AWS Certified DevOps Engineer – Professional candidates to understand these concepts and be able to apply them efficiently. With practice in configuring and utilizing EventBridge, you’ll be able to build robust, event-driven automation to support your DevOps workflows.