Build an Orchestrator in Go (From Scratch)

Develop a deep understanding of Kubernetes and other orchestration systems by building your own with Go and the Docker API.

Orchestration systems like Kubernetes can seem like a black box: you deploy to the cloud and it magically handles everything you need. That might seem perfect—until something goes wrong and you don’t know how to find and fix your problems. Build an Orchestrator in Go (From Scratch) reveals the inner workings of orchestration frameworks by guiding you through creating your own.

In Build an Orchestrator in Go (From Scratch) you will learn how to:

• Identify the components that make up any orchestration system
• Schedule containers on to worker nodes
• Start and stop containers using the Docker API
• Manage a cluster of worker nodes using a simple API
• Work with algorithms pioneered by Google’s Borg
• Demystify orchestration systems like Kubernetes and Nomad

Build an Orchestrator in Go (From Scratch) explains each stage of creating an orchestrator with diagrams, step-by-step instructions, and detailed Go code samples. Don’t worry if you’re not a Go expert. The book’s code is optimized for simplicity and readability, and its key concepts are easy to implement in any language. You’ll learn the foundational principles of these frameworks, and even how to manage your orchestrator with a command line interface.

About the technology

Orchestration frameworks like Kubernetes and Nomad radically simplify managing containerized applications. Building an orchestrator from the ground up gives you deep insight into deploying and scaling containers, clusters, pods, and other components of modern distributed systems. This book guides you step by step as you create your own orchestrator—from scratch.

About the book

Build an Orchestrator in Go (From Scratch) gives you an inside-out perspective on orchestration frameworks and the low-level operation of distributed containerized applications. It takes you on a fascinating journey building a simple-but-useful orchestrator using the Docker API and Go SDK. As you go, you’ll get a guru-level understanding of Kubernetes, along with a pattern you can follow when you need to create your own custom orchestration solutions.

What’s inside

• Schedule containers on worker nodes
• Start and stop containers using the Docker API
• Manage a cluster of worker nodes using a simple API
• Work with algorithms pioneered by Google’s Borg

About the reader

For software engineers, operations professionals, and SREs. This book’s simple Go code is accessible to all programmers.

Table of Contents

Part 1. Introduction

1. What is an orchestrator?

2. From mental model to skeleton code

3. Hanging some flesh on the task skeleton

Part 2. Worker

4. Workers of the Cube, unite!

5. An API for the worker

6. Metrics

Part 3. Manager

7. The manager enters the room

8. An API for the manager

9. What could possibly go wrong?

Part 4. Refactorings

10. Implementing a more sophisticated scheduler

11. Implementing persistent storage for tasks

Part 5. CLI

12. Building a command-line interface

13. Now what?

Review

‘…it’s time to understand how the toys we play with everyday work and this is the right book to start with!’ Emanuele Piccinelli

‘A great way to understand what happened behind the scenes with one orchestrator.’ Andres Sacco

‘If you truly want to understand how Kubernetes is working under the hood then you need to read this book. ‘ Geert Van Laethem

‘Recommended as a fundamental learning asset about orchestration systems. ‘ Christopher Villanueva

From the Back Cover

Orchestration systems like Kubernetes coordinate other software subsystems and services to create a complete organized system. Although orchestration tools have a reputation for complexity, they’re designed around few important patterns that apply across many aspects of software development.

Build an Orchestrator in Go reveals the inner workings of orchestration frameworks by guiding you as you design and implement your own using the Go SDK. As you create your own orchestration framework, you’ll improve your understanding of Kubernetes and its role in distributed system design. You’ll also build the skills required to design custom orchestration solutions for those times when an out-of-the-box solution isn’t a good fit.

Build an Orchestrator in Go teaches you to implement an orchestrator from scratch. You’ll discover the components that make up all orchestration systems, and use the Docker API and Go SDK to build layers of functionality from tasks, to workers, to the manager. Learn how to save on costs by maximising the usage of a cluster, or spread tasks among workers to avoid overload and downtime. Once you’ve built your working system, you’ll even implement a command line user interface to easily manage your orchestrator.

About the Author

Tim Boring is a staff engineer at Golioth. He has twenty years of experience in technology organizations ranging from small business to global enterprises. His career spans roles in technical support to site reliability and software engineering. Tim is most interested in the design of software systems and distributed systems in particular.