Using AWS CloudWatch Events to Trigger Cucumber Tests

Automated testing plays a crucial role in this process, and Cucumber is a popular tool for behavior-driven development (BDD) that helps you write clear, understandable tests. But how do you ensure these tests run automatically and efficiently? Enter AWS CloudWatch Events, a powerful tool that can automate your testing process. In this article, we’ll explore how to use AWS CloudWatch Events to trigger Cucumber tests, providing you with a robust and automated testing solution.

What is AWS CloudWatch Events?

AWS CloudWatch Events provides a near real-time stream of system events that describe changes in AWS resources. Using CloudWatch Events, you can monitor your AWS environment and automate responses to operational changes. For example, you can automatically start an EC2 instance when specific criteria are met, or in our case, trigger a Cucumber test suite.

Setting Up AWS CloudWatch Events

Before we dive into the integration with Cucumber, let’s set up AWS CloudWatch Events.

Create a Rule:
- Go to the CloudWatch console.
- In the navigation pane, choose “Rules”.
- Click on “Create rule”.
- Define the event source. For example, you might want to trigger tests based on a schedule, so choose “Event Source” as “Schedule” and set the schedule expression (e.g., cron(0 0 * * ? *) for daily at midnight).
Set the Target:
- After defining the event source, you’ll need to set the target. In this case, we will use AWS Lambda to execute our Cucumber tests.
- Choose “Add target” and select “Lambda function”.
- Choose the Lambda function you want to trigger.
Configure Event Details:
- Provide a name and description for the rule.
- Click “Create rule”.

Creating a Lambda Function to Trigger Cucumber Tests

Next, we need to create a Lambda function that will run our Cucumber tests.

Create a Lambda Function:
- Go to the Lambda console.
- Click on “Create function”.
- Choose “Author from scratch”.
- Provide a name for the function, e.g., RunCucumberTests.
- Choose a runtime. For this example, we will use Python 3.8.
- Click “Create function”.
Add Permissions:
- Ensure your Lambda function has the necessary permissions to interact with other AWS services. You may need to attach an IAM role with the appropriate policies.
Write the Lambda Function Code:

import subprocess
import json

def lambda_handler(event, context):
    # Path to your Cucumber tests
    cucumber_path = "/path/to/your/cucumber/tests"
    
    # Command to run your Cucumber tests
    command = f"cucumber {cucumber_path}"
    
    try:
        # Run the Cucumber tests
        result = subprocess.run(command, shell=True, check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        
        # Log the output
        print("Output:", result.stdout.decode())
        print("Error:", result.stderr.decode())
        
        # Return success response
        return {
            'statusCode': 200,
            'body': json.dumps('Cucumber tests executed successfully!')
        }
    
    except subprocess.CalledProcessError as e:
        # Log the error
        print("Error:", e.stderr.decode())
        
        # Return error response
        return {
            'statusCode': 500,
            'body': json.dumps('Cucumber tests execution failed!')
        }

Deploy the Lambda Function:
- Click “Deploy” to save your changes.

Writing Cucumber Tests

Now, let’s assume you have a simple Cucumber test set up. Here is an example:

1. Feature File (features/example.feature):

Feature: Example feature

  Scenario: Successful scenario
    Given I have a working Cucumber setup
    When I run my tests
    Then they should pass successfully

2. Step Definitions (features/step_definitions/steps.rb):

Given('I have a working Cucumber setup') do
  puts "Cucumber setup is working"
end

When('I run my tests') do
  puts "Running tests"
end

Then('they should pass successfully') do
  puts "Tests passed successfully"
end

Deploying and Testing

Package Your Lambda Function:
- Ensure all dependencies are packaged with your Lambda function. For example, you might use a Docker container to install dependencies and create a deployment package.
Upload Deployment Package:
- Upload your deployment package to the Lambda console.
Test the Setup:
- Manually test the Lambda function to ensure it executes your Cucumber tests correctly.
- Check the CloudWatch logs for the output and errors.

Monitoring and Notifications

To keep track of your tests and get notified of failures, you can set up CloudWatch Alarms and SNS (Simple Notification Service).

Create a CloudWatch Alarm:
- Go to the CloudWatch console.
- Choose “Alarms” and click “Create Alarm”.
- Select the relevant metric (e.g., Lambda function errors).
- Set the conditions and create the alarm.
Set Up SNS Notifications:
- Create an SNS topic.
- Subscribe your email or SMS to the topic.
- Add the SNS topic as an action for your CloudWatch alarm.

Conclusion

By integrating AWS CloudWatch Events with Cucumber, you can automate your testing process and ensure that your application is continuously validated against your defined behaviors. This setup not only improves the reliability of your software but also frees up valuable time for your engineering team to focus on development rather than manual testing. With AWS’s robust infrastructure and Cucumber’s clear and concise test definitions, you have a powerful combination for maintaining high-quality software.

If you found this article helpful and are interested in integrating Cucumber Automation Framework with AWS CloudWatch, I suggest you check out some of the other articles I’ve written for this series:

If you’re looking for a deeper dive into some of the concepts and specifics discussed in my article, feel free to reach out to me directly or as always you can checkout the official AWS CloudWatch Developer Documentation for more information.