mrpc-node

mrpc-node

A basic RPC wrapper around protobuf and websockets to facilitate writing web services and apps.

Features include:

• Uses proto3 to define services/messages
• Uses websockets for transport
• Friendly interfaces to define services/clients

This library is meant to be used in a nodejs runtime. To write clients that run in a browser, see mprc-web.

Usage

Code Generation

mRPC's typescript integration is built around ts-proto generated interfaces and types.

First, add that to your project:

yarn add --dev ts-proto

and install the protobuf compiler so you have the protoc command. Then, you can use these to generate typescript bindings for use with mRPC:

protoc \
  --plugin=protoc-gen-ts_proto=./node_modules/.bin/protoc-gen-ts_proto \
  --ts_proto_out=./src/gen \
  --ts_proto_opt=outputServices=generic-definitions,outputServices=default \
  --proto_path=../proto \
  ../proto/*.proto

Put that in a bash script for convenience to quickly update the typescript whenever you change the .proto files.

Writing Servers and Clients

Once you have the generated ts-proto types, you can simply import them, import the mrpc-node library and:

Define a service implementation, and add it to an RpcServer:

import { createServer } from "http";
import { RpcClientChannel, RpcServer } from "netrpc-node";
import {
  ClientGreeterClientImpl,
  Greeter,
  GreeterDefinition,
  HelloReply,
  HelloRequest
} from "./gen/helloworld"

...

class GreeterServiceImpl implements Greeter {
  async SayHello(request: HelloRequest): Promise<HelloReply> {
    return {
      message: "Hello " + request.name,
    }
  }
}

...

const httpServer = createServer();
const rpcServer = new RpcServer(httpServer, ORIGIN);
rpcServer.addService<Greeter>(new GreeterServiceImpl(), GreeterDefinition);

Alternatively, you can just use wrapSocket(impl, socket, definition) if you got a client socket some other way.

To create a client, create an RpcClientChannel around a hostname or a Socket object, and pass that into a ___ClientImpl's constructor:

// Import stuff

const channel = new RpcClientChannel({host: 'http://localhost:8080'});
const client = new GreeterClientImpl(channel);
...
const result = await client.SayHello({name: "Alice"});

See https://github.com/maunvz/mRPC/tree/main/samples for a full example of a server/client nodejs command line.