Book Image

gRPC Go for Professionals

By : Clément Jean
Book Image

gRPC Go for Professionals

By: Clément Jean

Overview of this book

In recent years, the popularity of microservice architecture has surged, bringing forth a new set of requirements. Among these, efficient communication between the different services takes center stage, and that's where gRPC shines. This book will take you through creating gRPC servers and clients in an efficient, secure, and scalable way. However, communication is just one aspect of microservices, so this book goes beyond that to show you how to deploy your application on Kubernetes and configure other tools that are needed for making your application more resilient. With these tools at your disposal, you’ll be ready to get started with using gRPC in a microservice architecture. In gRPC Go for Professionals, you'll explore core concepts such as message transmission and the role of Protobuf in serialization and deserialization. Through a step-by-step implementation of a TODO list API, you’ll see the different features of gRPC in action. You’ll then learn different approaches for testing your services and debugging your API endpoints. Finally, you’ll get to grips with deploying the application services via Docker images and Kubernetes.
Table of Contents (13 chapters)
10
Epilogue

Sending metadata

Another feature that builds upon contexts is the possibility to pass metadata through calls. In gRPC, these metadata can be HTTP headers or HTTP trailers. They are both a list of key-value pairs that are used for many purposes such as passing authentication tokens and digital signatures, data integrity, and so on. In this section, we are mostly going to focus on sending metadata through headers. Trailers are simply headers that are sent after a message and not before. They are less used by developers but are used by gRPC to implement streaming interfaces. Anyway, if you are interested, you can look at the grpc.SetTrailer function (https://pkg.go.dev/google.golang.org/grpc#SetTrailer).

Our use case will be to pass an auth token to the UpdateTasks RPC endpoint, and after checking it, we will decide to either update the task or return an Unauthenticated error. Obviously, we are not going to deal with how to generate the auth token because this is an implementation...