Summary

In this chapter, we started with monolithic architecture and discussed the drag it causes in being able to expand with new capabilities as well as time to market. Monolithic architectures are brittle and expensive to change. We read about how microservices architecture breaks that inertia and provides the momentum required to meet the ever-changing and never-ending appetite of digital consumers. We also saw how microservices architecture is modular, with every module being self-contained, and can be built and deployed independently of each other. Applications built using microservices architecture make use of best-of-breed technologies that are suitable for solving individual problems.

We then discussed the cloud and Kubernetes. The cloud provides utility-style computing with a pay-as-you-go model. Common cloud services include IaaS, PaaS, and SaaS. The cloud provides access to all infrastructure you may need without you needing to worry about the procurement of expensive hardware, data center costs, and so on. The cloud also provides you with software building blocks with which you can reduce your software development cycle. In microservices architecture, containers are the way to package application code. They provide consistency of environments and isolation between services, solving the noisy neighbor problem.

Kubernetes, on the other hand, makes the usage of containers easier by providing container life cycle management and solving many of the challenges of running containers in production. As the number of microservices grows, you start facing challenges regarding traffic management between microservices. Kubernetes does provide traffic management based on kube-proxy and iptables-based rules, but it falls short of providing application networking.

We finally discussed Service Mesh, an infrastructure layer on top of Kubernetes that is responsible for application networking. The way it works is by providing a data plane, which is basically a collection of application-aware service proxies, such as Envoy, that are then controlled by a set of components called the control plane.

In the next chapter, we will read about Istio, one of the most popular Service Mesh implementations.