Websockets

This book is for Go programmers who know a little networking, and for network engineers who know a little Go. There's no need to be an expert in either. So, in these chapters, we're building a tool together, Netkit, and it grows a bit more every time we solve a problem. And each chapter kicks off with a situation you might recognise, like a supplier recall, a partner network that's all over the place, or a backup that drags on for no good reason.

In this 2nd edition, I'm going to be working with you on a single app called OrderDesk. We'll build its inventory, roles and secrets, and then we'll patch its servers, provision its cloud resources and deploy it to Kubernetes. Later, we'll watch it with Prometheus, heal it with Event-Driven Ansible and diagnose its failures with playbooks that collect evidence in seconds. Then, in the last few chapters, we'll start inviting AI agents through tools and MCP servers, while approvals and check mode make sure that everyone keeps control of the decisions. You don't need to be a pro programmer to follow along.

This book is not just a Python course with a networking flavour or a networking course with a few scripts attached. You already know how routing converges, why VLANs leak, and what a half-open TCP session looks like on the wire. What this book adds is the ability to transform that knowledge into code that runs across hundreds of devices, reports accurately on its findings and never makes changes that cannot be undone.

Answered sounds like it worked. Twice, it didn't. This book measures exactly where six seconds of silence goes in a real phone call, and does not stop measuring for the next thirty-four chapters.

Whenever I've worked on a service, there's always been a morning when it stops being a demo. Then traffic arrives from somewhere nobody planned for, a nightly job overruns into the working day, and a number somebody chose months ago turns out to be wrong. That morning was a different story, though. The thing that separates a survival program from one that doesn't is a set of habits, and those habits can be learned. So, this second edition is organised around them rather than around syntax.

In this book, we plan before we act, we preview before we commit, we gate on evidence rather than on hope, and we write the recovery before we take the risk. By the time you get to the last chapter, you'll be familiar with the switches over NETCONF, server provisioning, building overlays, traffic inspection, cloud network provisioning, Kubernetes resource application, RDMA fabric validation, inference traffic routing, and reporting your findings through an interface that an assistant can query.

Build real-time web apps that hold up beyond the demo. This hands-on guide takes you from WebSocket fundamentals and Socket.IO essentials to security, Redis scaling, monitoring and production deployment. Learn how the pieces work, why they matter and how to build fast, reliable systems ready for serious traffic.