What this book covers
Chapter 1, Introducing Service Meshes, covers the fundamentals of cloud computing, microservices architecture, and Kubernetes. It then outlines the context as to why a Service Mesh is required and what value it delivers. If you don’t have hands-on experience in dealing with large-scale deployment architecture using Kubernetes, the cloud, and microservices architecture, then this chapter will familiarize you with these concepts and give you a good foundation for understanding the more complex subjects in the subsequent chapters.
Chapter 2, Getting Started with Istio, describes why Istio has experienced viral popularity among the Service Mesh technologies available. The chapter then provides instructions to install and run Istio and walks you through Istio’s architecture and its various components. Once installed, you will then enable Istio sidecar injection in an example application packaged with the Istio installation. The chapter provides a step-by-step look at the pre- and post-enablement of Istio in the example application to give you an idea of how Istio works.
Chapter 3, Understanding Istio Control and Data Planes, dives deeper into Istio’s control plane and data plane. This chapter will help you understand the Istio control plane so you can plan the installation of control planes in a production environment. After reading this chapter, you should be able to identify the various components of the Istio control plane including istiod, along with the functionality they each deliver in the overall working of Istio. The chapter will also familiarize you with Envoy, its architecture, and how to use Envoy as a standalone proxy.
Chapter 4, Managing Application Traffic, provides details on how to manage application traffic using Istio. The chapter is full of hands-on examples, exploring the management of Ingress traffic using the Kubernetes Ingress resource and then showing how to do this using Istio Gateway, along with securely exposing Ingress over HTTPS. The chapter provides examples of canary releases, traffic mirroring, and routing traffic to services outside the mesh. Finally, we’ll see how to manage traffic egressing from the mesh.
Chapter 5, Managing Application Resiliency, provides details on how to make use of Istio to increase the application resiliency of microservices. The chapter discusses various aspects of application resiliency including fault injection, timeout and retries, load balancing, rate limiting, circuit breakers, and outlier detection, and how each of these is addressed by Istio.
Chapter 6, Securing Microservices Communication, dives deeper into advanced topics on security. The chapter starts with explaining Istio’s security architecture, followed by implementing mutual TLS for service communication both with other services in the mesh and with downstream clients outside the mesh. The chapter will walk you through various hands-on exercises to create custom security policies for authentication and authorization.
Chapter 7, Service Mesh Observability, provides insight into why observability is important, how to collect telemetry information from Istio, the different types of metrics available and how to fetch them via APIs, and how to enable distributed tracing for applications deployed in the mesh.
Chapter 8, Scaling Istio to Multi-Cluster Deployments Across Kubernetes, walks you through how Istio can be used to provide seamless connectivity between applications deployed across multiple Kubernetes clusters. The chapter also covers multiple installation options for Istio to achieve high availability and continuity with the Service Mesh. The chapter covers advanced topics of Istio installation and familiarizes you with how to set up Istio in a primary-remote configuration on multiple networks, primary-remote configuration on a single network, multi-primary configuration on different networks, and multi-primary configuration on a single network.
Chapter 9, Extending Istio Data Plane, provides various options to extend the Istio data plane. The chapter discusses EnvoyFilter and WebAssembly in great detail and examines how they can be used to extend the functionality of the Istio data plane beyond what is offered out of the box.
Chapter 10, Deploying the Istio Service Mesh for Non-Kubernetes Workloads, provides a background as to why organizations have a significant number of workloads still deployed on virtual machines. The chapter then introduces the concept of hybrid architecture, a combination of modern and legacy architecture, followed by showing how Istio helps to marry these two worlds of legacy and modern technologies and how you can extend Istio beyond Kubernetes to virtual machines.
Chapter 11, Troubleshooting and Operating Istio, provides details of common problems you will encounter when operating Istio and how to distinguish and isolate them from other issues. The chapter then covers various techniques to analyze and troubleshoot the day-2 problems often faced by operations and reliability engineering teams. The chapter provides various best practices for deploying and operating Istio and shows how to automate the enforcement of best practices using OPA Gatekeeper.
Chapter 12, Summarizing What We Have Learned and the Next Steps, helps you revise what you’ve learned from this book by putting it to use to deploy and configure an open source application, helping you gain confidence in employing your learning in real-world applications. The chapter also provides various resources you can explore to advance your learning and expertise in Istio. Finally, the chapter introduces eBPF, an advanced technology poised to make a positive impact on service meshes.
Appendix – Other Service Mesh Technologies, introduces other Service Mesh technologies including Linkerd, Gloo Mesh, and Consul Connect, which are gaining popularity, recognition, and adoption by organizations. The information provided in this appendix is not exhaustive, but rather aims to make you familiar with the alternatives to Istio and help you form an opinion on how these technologies fare in comparison to Istio.