What is Kubeless? A Comprehensive Definition for Beginners

Kubeless, a popular and fast-growing open-source serverless framework, provides developers a way to run their code without having to manage the underlying infrastructure. As of 2021, Kubeless is thriving in the IT industry with an impressive 4.7k stars on GitHub and has been widely adopted by developers around the world, thanks to its native integration with Kubernetes. Businesses of all sizes can effectively utilize the serverless architecture to scale their applications and save resources on infrastructure management.

“Kubeless is the Kubernetes-native serverless framework that takes full advantage of the platform’s flexibility and scalability – a natural evolution for the modern cloud infrastructure.” – Kelsey Hightower, GoogleCloud Developer Advocate

What is Kubeless? Definition of Kubernetes-native Serverless

Kubeless is a Kubernetes-native serverless framework, designed for deploying and managing serverless applications on a Kubernetes cluster. It enables users to run their code inside Kubernetes without provisioning or managing servers, thus simplifying application deployment and significantly reducing operational costs. Kubeless supports a variety of languages and runtimes, such as Python, Node.js, Ruby, PHP, and .NET Core, among others.

ℹ️ Synonyms: Serverless, FaaS (Function-as-a-Service), Cloud Functions

How it Works

Kubeless works by utilizing Kubernetes Custom Resource Definitions (CRDs) to define functions and trigger events. When a user deploys a Kubeless function, it creates a custom object in the Kubernetes cluster, which Kubeless watches and manages. Upon detecting an event or receiving an HTTP request, Kubeless automatically scales the corresponding function’s replicas to handle the incoming requests.

Kubeless also supports event-driven architecture – users can specify event sources to trigger their functions, such as Pub/Sub messaging systems like Kafka or NATS, or even external services like AWS S3.

Behind the scenes, Kubeless utilizes Kubernetes components like Deployments, ConfigMaps, and Services to deploy, run, and manage each function. This tight integration with Kubernetes ensures that Kubeless inherits the robustness, scalability, and security features of the Kubernetes ecosystem.

Benefits of using Kubeless

• Seamless integration with Kubernetes: Kubeless is built specifically for Kubernetes, allowing developers to take advantage of its powerful features and ecosystem.
• Easy deployment: Deploying functions in Kubeless is as simple as executing a single command with a function file and dependencies.
• Language and framework agnostic: Kubeless supports multiple languages and their respective runtime environments, catering to a wide range of developers and applications.
• Scalability: Kubeless functions auto-scale according to the incoming traffic, ensuring optimal use of resources and minimizing operational costs.
• Event-driven architecture support: Kubeless provides native support for event sources, making it easy to build event-driven applications.

Kubeless use cases

Kubeless is versatile and can be used in various applications and scenarios:

Code Examples

const Kubeless = require('kubeless');
const k8s = require('@kubernetes/client-node')

const kubelessClient = Kubeless(k8s.KubeConfig('/path/to/kubeconfig.file'));

// Get Functions
kubelessClient.functions.get().then((functions) => {
  console.log(functions);
});

// Create Function
const functionSpec = {
  metadata: {
    name: 'my-function',
    namespace: 'default',
  },
  spec: {
    runtime: 'nodejs8',
    handler: 'handler.myFunction',
    deps: '{"dependencies": {"lodash": "4.17.5"}}',
    functionContent: "module.exports = {myFunction: (event, context) => context.succeed('Hello from Kubeless!')};",
  },
};

kubelessClient.functions.create(functionSpec).then((createdFunction) => {
  console.log(createdFunction);
});

// Delete Function
kubelessClient.functions.delete('my-function', 'default').then((deletedFunction) => {
  console.log(deletedFunction);
});

Best Practices

When building applications with Kubeless, it’s essential to follow best practices to optimize performance, security, and scalability. Keep your functions small and focused on a single responsibility so they can be efficiently scaled and easier to maintain. Embrace an event-driven architecture and decouple the different components of your application. Additionally, monitor and collect metrics to analyze function performance and spot potential bottlenecks. Always use the latest version of Kubeless and its underlying components to ensure you have the most up-to-date features, compatibility, and security patches.

Most recommended books about Kubeless

Kubeless is supported and documented by a vibrant community of developers and users. Although no dedicated books have been written specifically about Kubeless, you can find relevant and useful information about serverless architecture and Kubernetes in the following books:

1. “Kubernetes: Up and Running” by Kelsey Hightower, Brendan Burns, and Joe Beda.
2. “Serverless Architectures on AWS” by Dr. Peter Sbarski.
3. “Serverless Design Patterns and Best Practices” by Brian Zambrano.

Conclusion

Kubeless is an invaluable tool for developers and businesses looking to build scalable, event-driven, and serverless applications on a powerful platform like Kubernetes. With seamless integration and language support, adopting Kubeless is an excellent choice for modern application development. By following best practices and staying up-to-date with the ecosystem, users can take advantage of all the benefits Kubeless offers and build robust and efficient applications.

Tags: apigateway, cloudnative, container, eventdriven, functions.