gRPC: Up and Running

Chapter 8. The gRPC Ecosystem

In this chapter, we’ll explore some of the projects that are not part of the core gRPC implementation but could be quite useful in building and running gRPC applications for a real-world use case. These projects are part of the gRPC Ecosystem parent project, and none of the technologies mentioned here are mandatory to run gRPC applications. If you have a similar requirement that a given project offers, explore and evaluate those technologies.

Let’s begin our discussion with the gRPC gateway.

gRPC Gateway

The gRPC gateway plug-in enables the protocol buffer compiler to read the gRPC service definition and generate a reverse proxy server, which translates a RESTful JSON API into gRPC. This is specifically written for Go, to support invoking gRPC service from both gRPC and HTTP client applications. Figure 8-1illustrates how it provides the ability to invoke gRPC service in both gRPC and RESTful ways.

As shown in the figure, we have a ProductInfo service contract and using the contract we build a gRPC service called ProductInfoService. Earlier we built a gRPC client to talk with this gRPC service. But here, instead of building a gRPC client we will build a reverse proxy service, which exposes RESTful API for each remote method in the gRPC service and accepts HTTP requests from REST clients. Once it receives an HTTP request, it translates the request into a gRPC message and calls the remote method in the backend service. The response message from the ...