How to use postman for automated tests that run on a CI pipeline?

In the realm of API testing and automation, Postman has emerged as a powerful tool that offers a user-friendly interface for creating, managing, and executing API tests. However, the question remains: is Postman a viable option for running automated tests on a Continuous Integration (CI) pipeline? This article aims to explore this topic in depth, providing a step-by-step guide along with screenshots to illustrate the process. We will define key terminologies, showcase the setup, and discuss the benefits and considerations of using Postman in a CI pipeline for automated testing.

Key Terminologies

1. Postman

Postman is a popular API development and testing platform that provides an intuitive interface for creating, managing, and executing API requests.

2. Automated Tests

Automated tests are scripts or programs that are designed to automatically execute predefined actions, verify results, and report on the outcomes of those actions.

3. CI Pipeline

A Continuous Integration (CI) pipeline is an automated process that allows developers to integrate code changes into a shared repository frequently. It involves stages such as building, testing, and deploying code.

4. API Testing

API testing involves evaluating the functionality, performance, and security of an API by sending requests and validating responses.

Steps:

Step 1: How to Set Up Postman Collection.

Begin by creating a Postman collection. This collection will contain your API requests organized into folders. Use the Postman app to create and manage your collection.

Create a New Collection:

• In the Postman interface, locate the “Collections” tab on the left sidebar.
• Click the “+ New” button to create a new collection.

Name Your Collection:

• Give your collection a meaningful name that reflects its purpose.

Add Requests to Your Collection:

• With the collection selected, click the “Add a request” button to create a new request.
• Fill in the necessary details such as request type (GET, POST, etc.), URL, headers, body, etc.

Organize Requests into Folders:

• You can create folders within your collection to group related requests together.
• Right-click on the collection, select “Add Folder”, and provide a name.

Save Your Collection:

• Postman automatically saves your collection as you add requests. You can see the “Save” indicator at the top right.

Step 2: Export Your Postman Collection.

Export your collection in a format compatible with your CI/CD tool. JSON format is commonly used.

Export Postman Collection

Step 3: Choose a CI/CD Tool.

Select a CI/CD tool that suits your project needs. For this example, we’ll use Jenkins.

Step 4: Create a CI Configuration File.

Create a Jenkins file (or a configuration file in your chosen CI/CD tool) to define the steps for your CI pipeline.

Jenkins Pipeline script

pipeline
{
    agent any stages
    {
        stage('Build')
        {
            steps
            {
                // Your build steps here
            }
        }
        stage('Test')
        {
            steps
            {
                // Add Postman testing step
            }
        }
    }
}

Step 5: Install Postman on the CI Runner.

In your CI pipeline configuration, include a step to install Postman on the CI runner. Use a package manager or download it directly.

package manager example

Step 6: Add Environment Variables.

If your collection relies on environment variables, add them to your CI environment configuration.

Environment Variables

Step 7: Integrate Postman into Your CI Pipeline.

Within your CI configuration file, add a step to run Postman tests using the exported collection and any necessary environment variables.

Jenkins Pipeline script

stage('Test')
{
    steps
    {
        script
        {
            sh 'newman run MyCollection.json --env-var BASE_URL=$BASE_URL'
        }
    }
}

Step 8: Run Your CI Pipeline.

Commit your Jenkins file and push it to your repository. Trigger the CI pipeline to start automated testing.

CI (Jenkins) Pipeline

Step 9: Configure Notifications.

Set up notifications to receive status alerts from your CI pipeline. This ensures you’re informed about test results.

Benefits and Considerations

Benefits of Using Postman for Automated Tests in CI Pipeline

1. Ease of Use: Postman provides an intuitive interface for creating and managing tests.
2. Wide Range of Features: Postman supports various authentication methods, environments, and data-driven testing.
3. Integration with CI Tools: Postman can be easily integrated into popular CI/CD platforms.

Considerations of Using Postman for Automated Tests in CI Pipeline

1. Resource Intensive: Running extensive test suites in Postman on a CI pipeline may require substantial computing resources.
2. License and Pricing: Consider the licensing model and pricing plans for Postman, especially in enterprise environments.

Conclusion

By following these steps, you can effectively automate API testing using Postman within your CI pipeline. This ensures that your APIs are thoroughly tested with every code change, maintaining the integrity of your application.