Implement a gRPC Server

Distributed Services with Go — by Travis Jeffery (34 / 84)

👈 Compile with the gRPC Plugin | TOC | Register Your Server 👉

Because the compiler generated a server stub, the job left for us is to write it. To implement a server, you need to build a struct whose methods match the service definition in your protobuf.

Create an internal/server directory tree in the root of your project by running mkdir -p internal/server. Internal packages are magical packages in Go that can only be imported by nearby code. For example, you can import code in /a/b/c/internal/d/e/f by code rooted by /a/b/c, but not code rooted by /a/b/g. In this directory, we’ll implement our server in a file called server.go and a package named server. The first order of business is to define our server type and a factory function to create an instance of the server.

Here’s the code we need to add to our server.go file:

ServeRequestsWithgRPC/internal/server/server.go

​ ​package​ server
​ 
​ ​import​ (
​         ​"context"​
​ 
​         api ​"github.com/travisjeffery/proglog/api/v1"​
​         ​"google.golang.org/grpc"​
​ )
​ 
​ ​type​ Config ​struct​ {
​         CommitLog CommitLog
​ }
​ 
​ ​var​ _ api.LogServer = (*grpcServer)(nil)
​ 
​ ​type​ grpcServer ​struct​ {
​         api.UnimplementedLogServer
​         *Config
​ }
​ 
​ ​func​ newgrpcServer(config *Config) (srv *grpcServer, err ​error​) {
​         srv = &grpcServer{
​…