Testing Kubernetes Applications

Kubernetes enabled the use of a Cloud Native model to build, deploy and scale applications. But it also introduces some challenges on how to test these application, or rather modules, effectively.

What Tests Can I Use for My Microservices?

There are common types of test that you can run with any application, but microservices architecture that run on Kubernetes introduce a new set of scenarios that need to be tested as well, making the list of the types of tests you can run for your microservices architecture longer.

Here's a list of test types:

• Unit Tests: These tests focus on individual components or functions of a microservice. They are usually performed during the development phase and don't involve Kubernetes.
• Integration Tests: Integration tests check if different components of an application work together as expected. They can involve testing communication between microservices or databases and interactions with external APIs.
• End-to-End (E2E) Tests: E2E tests simulate user workflows and verify that the entire application functions as expected from the user's perspective. These tests often require a Kubernetes environment to run the application components.
• Performance or Load Tests: Performance tests assess the application's ability to handle load and maintain responsiveness under various conditions. These tests may involve stress testing, load testing, and benchmarking on a Kubernetes cluster.
• Resilience Tests or Chaos Tests: This type of tests evaluate an application's ability to recover from failures and continue functioning. They can involve chaos testing, failover testing, and disaster recovery testing on a Kubernetes cluster.

Challenges of Running Tests in Kubernetes

There are amazing tools that can run multiple types of types of tests in Kubernetes, but they all have similar challenges that you might face when running these tests.

These challenges include:

• Managing long pipeline of tests: putting all your test in a single monolith CI/CD pipeline can slow down heavily the Integration and Deployment of the microservices.
• Storing the result of tests: all test tools generate artifacts, these could be text based or it could be screenshot or a video of your app. You will have to think of how to store these artifacts in order to retrieve them and see what went wrong.
• Knowing when to run a test: usually tests are run in a CI/CD pipeline, but not every type of test should be run with every execution of CI/CD, for example, compute-intensive tests or load tests should be run in your CI/CD pipeline.
• Retriggering of tests: if your tests live in a CI/CD pipeline and you want to retrigger a test, you will have to retrigger the entire CI/CD pipeline. This can incur huge wait time specially if your pipelines are long.

These are some of the tests challenges we faced when building out application with a microservice architecture. The right strategy to operationally manage these tests should help scale your testing efforts in your DevOps lifecycle.

Where an When Can I Run My Tests?

Not all the tests are run at the same time and from the same place. For different scenarios and test types there's an optimal time in the DevOps lifecycle where you can test the application.

• Unit tests: These tests usually have a fast feedback loop that would enable developers to run them in their machines in seconds and once deployed, they can run in your Continuous Integration pipeline quickly.
• Integration tests: These tests are usually also executed in the Continuous Integration pipeline as they tend to be relatively fast and if well
• End-to-End (E2E) tests: E2E tests . These tests tend to test out the entire system so you want to be flexible on when to run them. Your CI/CD pipeline can be a place to hold these tests, but they tend to overcomplicate how you orchestrate the execution of the test and the retrieval of the results.
• Performance or Load tests: These tests can be scheduled at specific intervals during the development cycle or triggered by specific events such as a new release candidate (or manually ;)). Performance tests should be executed in an environment that closely resembles the production environment to accurately gauge the application's performance under real-world conditions.

What Tools Can I Use to Test My Microservices?

As described earlier that are different types of tests that you can run in Kubernetes and at different

1. Artillery: Artillery is a load testing tool that can be used to simulate high traffic on a Kubernetes application. It can help you identify performance issues, bottlenecks, and other issues that may arise under heavy load.
2. Curl: Curl is a command-line tool that can be used to make HTTP requests to Kubernetes resources like pods, services, and deployments. You can use it to test connectivity and troubleshoot issues with Kubernetes resources.
3. Cypress: Cypress is an end-to-end testing tool that can be used to test the functionality of your Kubernetes application. It can help you identify and fix issues with your application's user interface and workflows.
4. Ginkgo: Ginkgo is a testing framework that can be used to write and run automated tests for your Kubernetes application. It's designed to be highly configurable and can be used to test a variety of different scenarios.
5. Gradle: Gradle is a build automation tool that can be used to build and deploy your Kubernetes application. It can help you manage dependencies, run tests, and package your application for deployment.
6. JMeter: JMeter is a load testing tool that can be used to simulate high traffic on your Kubernetes application. It can help you identify performance issues and bottlenecks under different load conditions.
7. K6: K6 is another load testing tool that can be used to test the performance of your Kubernetes application. It's designed to be developer-friendly and can be used to write and run tests in JavaScript.
8. KubePug: KubePug is a tool that can be used to scan your Kubernetes manifests for potential security vulnerabilities. It can help you identify security issues before they become a problem.
9. Maven: Maven is a build automation tool that can be used to build and deploy your Kubernetes application. It's designed to be highly configurable and can be used to manage dependencies, run tests, and package your application for deployment.
10. Playwright: Playwright is an end-to-end testing tool that can be used to test the functionality of your Kubernetes application. It's designed to be highly configurable and can be used to test a variety of different scenarios.
11. Postman: Postman is a tool that can be used to test your Kubernetes API endpoints. It's designed to be highly configurable and can be used to test a variety of different scenarios.
12. SoapUI: SoapUI is a tool that can be used to test SOAP and REST web services. It can help you test the functionality of your Kubernetes application's API endpoints and identify issues with your application's data exchange.

Conclusion

In conclusion, Kubernetes has revolutionized the way we build, deploy, and scale applications using a Cloud Native model. However, it also brings unique challenges in testing microservices effectively.

To overcome these challenges and scale testing efforts in your DevOps lifecycle, it's essential to adopt the right strategy for managing and executing tests. By doing so, you can ensure the reliability, performance, and security of your Kubernetes-based microservices applications.