RPC

• It stands for Remote Procedure Call.
• A communication mechanism.
• It is almost the same as though we have access to the methods/function defined in another program.
• Can be used for inter-service communications.
• Supper efficient.

[!CAUTION]

This is still a network call. So do not call it like your codes who are living in the same codebase.

• What the heck is stub?

  In gRPC we call them protobuf. More on that here.

[!NOTE]

We can use any application level protocol for sending requests and receiving responses:

• TCP: HTTP1, HTTP2.
• UDP.
• Websockets.
• etc.

gRPC

• An open-source rewrite of RPC used by Google.
• Why gRPC?
  1. It uses only HTTP2 as its transport layer.
  2. Protocol buffer as our data exchange format.
• No browser support yet, but a good thing to have for inter-service communication in a microservice architecture.

NestJS

1. Follow the official documentation opn how to bootstrap a NestJS app + gRPC.

   pnpx create-nx-workspace grpc --preset=nest --appName nestjs-client --bundler esbuild --packageManager pnpm --nxCloud skip
   

2. I also love perfectionist for a good reason and that is the tidiness it gives you for little conf, so I highly recommend you take a look at it in their official doc.

   Or if you’re looking for something on how to get up to speed I guess this commit can be a real quick intro to how to use it. BTW I appreciate it if you give my repo a star in case it was helpful :slightly_smiling_face:.

   nx run-many -t lint --fix
   

3. Write you’re protobuf file like what I did here at user.proto.

4. Use the ts-proto to auto generate the interfaces and decorators for your gRPC controller.

   {
     "scripts": {
       "grpc:gen": "npx protoc --plugin=./node_modules/.bin/protoc-gen-ts_proto --ts_proto_opt=fileSuffix=.interface --ts_proto_opt=nestJs=true --ts_proto_opt=addNestjsRestParameter=true --ts_proto_out={projectRoot}/src/assets/interfaces -I {projectRoot}/src/assets/ {projectRoot}/src/assets/*.proto"
     }
   }
   

   For the complete solution look at this.

5. Now just run the npm run grpc:gen or if you’re using Nx just run nx grpc:gen projectName.

6. Congrats, you have your types and decorators. So let’s put them into use.

[!TIP]

For a complete example look at the nestjs-client.

Ref

• Introduction to RPC - Remote Procedure Calls.