Dr. Siddharth Agarwal
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8 Chapters Code-Centric Open Source

OpenFaaS: How, Why, and Where in Code

An AI-first, code-centric tutorial on OpenFaaS — the Kubernetes-native serverless framework. Each chapter explores the internal mechanics of the OpenFaaS Gateway, showing not just what components do, but how and why they work at the source-code level.

OpenFaaSOpenFaaS KubernetesKubernetes GoGo PrometheusPrometheus
Start Learning GitHub
Content

8 Chapters

Each chapter is a standalone learning module. Start from Chapter 1 or jump to any topic.

Chapter 01

Gateway Application

What is the Gateway? Why is it the control plane? Where is the entry point in code?

Control Plane → Chapter 02

Configuration

How is the Gateway configured? What knobs control behaviour? Where are defaults set?

Settings & Knobs → Chapter 03

API Definition

Where is the REST API defined? How does the Gateway route requests to handlers?

REST API & Routing → Chapter 04

Request Middleware

How does the Gateway transform and authenticate incoming requests in the middleware chain?

Transformation & Auth → Chapter 05

Request Handling

How are functions invoked (sync/async)? Where does queueing happen? What drives concurrency?

Sync/Async & Queueing → Chapter 06

Function Scaling

How does OpenFaaS auto-scale functions from 0 to N replicas? What triggers a scaling decision?

Auto-scaling 0 to N → Chapter 07

Provider Interaction

How does the Gateway interact with the Kubernetes provider? Where is the provider API called?

Kubernetes Integration → Chapter 08

Metrics & Monitoring

How are Prometheus metrics exposed? What do they represent? How does observability enable scaling?

Prometheus & Observability →
Approach

Why This Tutorial?

Code-First

Every concept is anchored to actual Go source code in the OpenFaaS Gateway repository. You learn not just what, but how and where in the codebase.

Architecture-Driven

Chapters follow the request lifecycle — from Gateway startup through configuration, API routing, middleware, handler invocation, and scaling decisions.

Kubernetes-Native Context

Learn serverless computing in the context of modern Kubernetes environments, CRDs, and cloud-native observability tooling.

Setup

Getting Started

Prerequisites

  • Basic understanding of Kubernetes and serverless concepts
  • Familiarity with Go programming language
  • Access to a Kubernetes cluster (MicroK8s or kind works)

Clone Repository

Get all chapters and source references:

git clone https://github.com/SidAg26/
OpenFaaS-How-Why-and-Where-in-Code.git

Recommended Path

  • Begin with Chapter 1 (Gateway Application) for foundational context
  • Proceed sequentially — each chapter builds on the previous
  • Jump to Chapter 6 or 8 for scaling/observability deep-dives