What is Envoy, and why might I need it?

Envoy (https://www.envoyproxy.io/) is a C++ open source service mesh and edge proxy geared toward microservice deployments. Developed by a team at Lyft, it is especially useful for teams developing Kubernetes-hosted applications, such as the ones you have seen throughout this book.

So, why exactly would we need to deploy Envoy? When developing cloud-based production systems that use multiple containers to host a distributed service, many of the problems you will encounter are related to observability and networking.

Envoy aims to solve these two problems by introducing a proxy service that offers runtime-configurable networking and metrics collection that can be used as a building block for creating higher-level systems that manage these concerns. Whether you're building out a small distributed application or a large microservice architecture designed around the service mesh model, Envoy's features allow us to abstract the thorny...