Chapter 1: Introduction to Serverless in Kubernetes

The concept of serverless computing is often viewed as the next evolution in cloud technology. Typically, organizations transition from on-premises virtual machines to utilizing containers on a PaaS platform, ultimately seeking a serverless solution. This progression reflects a technological shift towards infrastructure abstraction.

At its core, serverless computing allows developers to concentrate exclusively on application development, eliminating concerns about the underlying infrastructure. This paradigm initially emerged with Function as a Service (FaaS), gaining traction through offerings like Amazon Lambda and subsequently adopted by other major cloud providers.

Historically, serverless was seen as an alternative to containerization, which often requires extensive technical expertise for production management. However, this perception is changing as serverless methodologies become integrated across various platforms. Numerous services, particularly in the Software as a Service (SaaS) domain, exemplify this trend. For instance, Netlify enables seamless web application deployment without the need for infrastructure management, while TIBCO Cloud Integration offers an iPaaS solution that equips users with necessary technical resources to deploy integration services.

Furthermore, major cloud platforms—such as Azure, AWS, and GCP—have embraced this principle, abstracting infrastructure management to allow users to focus on core services like messaging and machine learning.

In the Kubernetes ecosystem, there are two pivotal layers that embody this serverless approach. The primary layer consists of managed Kubernetes services offered by leading platforms, where users are shielded from the complexities of Kubernetes management, focusing solely on worker nodes. The second layer can be observed in AWS’s EKS combined with Fargate architecture, which eliminates the need for worker node management altogether.

While serverless computing is making strides across various domains, this article will specifically delve into the implementation of FaaS within a Kubernetes ecosystem. The central question remains: what advantages does this approach offer?

The primary benefit of FaaS lies in its ability to adhere to a zero-scale model. Functions are activated only upon execution, a critical feature when managing or financing your infrastructure. For instance, consider a typical microservice; its resource consumption varies with load, but it still requires memory to remain operational, even when idle. This idle resource consumption can accumulate significantly across multiple microservices, costing enterprises valuable resources.

Moreover, the serverless model aligns seamlessly with Event-Driven Applications (EDA). Services can remain dormant, awaiting specific triggers to initiate processing, thereby optimizing resource utilization.

So, how can one enable this serverless approach in existing infrastructures? One essential consideration is that not all technologies or frameworks are suitable for this model. Successful implementation demands meeting specific criteria:

1. Quick Startup: Logic must load swiftly upon request to prevent service delays.
2. Statelessness: Services should not maintain state between executions.
3. Disposability: Services should be capable of graceful shutdowns.

Several frameworks can help incorporate these principles into your Kubernetes environment:

• KNative: Supported by the CNCF, KNative is increasingly included in various Kubernetes distributions, such as Red Hat OpenShift.
• OpenFaaS: Created by Alex Ellis, this framework is widely adopted for its serverless capabilities.

While other alternatives like Apache OpenWhisk, Kubeless, and Fission exist, KNative and OpenFaaS are the most prevalent choices in the current landscape. For those interested in further exploring alternative frameworks, an article from CNCF provides additional insights.

In this video, you can learn about scaling your Kubernetes cluster in a cost-effective manner with practical tips to reduce expenses.

This beginner-friendly video provides a comprehensive overview of Kubernetes cluster autoscaling, making it accessible for newcomers.