Building a Microservice Architecture with Node.js, TypeScript, and gRPC
Published: 2023-04-26 13:33:51



## Building a Microservice Architecture with Node.js, TypeScript, and gRPC 

Modern web applications tend to contain a large number of interconnected components that must communicate reliably. Leveraging microservices architecture presented by Node.js, TypeScript, and gRPC can be a great way to build this kind of reliable architecture. In this blog post we will explore building a microservice architecture with these three technologies and showcase how to get started. 

## What is a Microservice Architecture?

A microservice architecture is an architectural style for developing large-scale applications. It is composed of single-function services that can be independently managed and deployed. This approach has gained tremendous popularity among developers innovating on the web due to its scalability and flexibility.

## Why Node.js, TypeScript and gRPC

Node.js is a popular web development framework used for creating web applications and APIs. It is highly performant and enables developers to quickly and easily build sophisticated web applications. 

TypeScript is a statically typed language developed by Microsoft. It is a superset of JavaScript that adds features such as type checking and class-based object-oriented programming.

gRPC is a modern, open-source, high performance remote procedure call protocol developed by Google. It is used to make efficient, low-latency remote calls to services over the network.

## Building the Architecture

We can now get started on building our architecture. The first step is to create a new directory for our project, initialize the package.json and install the necessary dependencies. In our case, this includes Node.js, TypeScript, and gRPC. 

```bash
mkdir microservices
cd microservices
npm init -y
npm install --save grpc @types/grpc
```

Next, let’s install the TypeScript compiler so that we can compile our TypeScript code into JavaScript.

```bash
npm install --save typescript
```

Once we have the dependencies installed, we can write our TypeScript code. Here is a simple example of a gRPC service that returns a list of users.

```typescript
import { Service, ServerUnaryCall, ServerWritableStream } from 'grpc';

export interface IUserService extends Service {
   listUsers: ServerUnaryCall<GetUserRequest, GetUserResponse>,
}

export class UserService implements IUserService {
  public listUsers = (call: ServerUnaryCall<GetUserRequest, GetUserResponse>): void => {
    const users = [
      { id: 1, name: 'Jane Doe' },
      { id: 2, name: 'John Doe' },
    ];

    call.send(users);
  }
}
```

Now that we have this service written, we can generate the gRPC service definition. This is done using the `protoc` command:

```
protoc -I=api --js_out=import_style=commonjs,binary:. --grpc_out=. --plugin=protoc-gen-grpc=`which grpc_plugin` api/user.proto
```

This will generate two files, `user_grpc_pb.js` and `user_pb.js`, which contain the definitions of our gRPC service. We can now use this in our application. 

The next step is to create the server. This is done using the `grpc.Server` class. The server is responsible for setting up the gRPC calls and managing the incoming and outgoing requests and responses. 

```typescript
import * as grpc from 'grpc';
import { UserService, IUserService } from './services/user';

const server = new grpc.Server();

server.addService(UserService as grpc.ServiceDefinition<IUserService>);

server.bind('localhost:50051', grpc.ServerCredentials.createInsecure());
server.start();
```

Finally, we can create the client. This is done using the `grpc.Client` class and we can use it to make remote calls to our gRPC server.

```typescript
import * as grpc from 'grpc';
import { UserService } from './services/user';

const client = new UserService(
  'localhost:50051',
  grpc.credentials.createInsecure(),
);

client.listUsers((err, users) => {
  if (err) {
    console.error(err);
  } else {
    console.log(users);
  }
});
```

## Summary

We have now explored building a microservices architecture with Node.js, TypeScript, and gRPC. We were able to create a service, generate the gRPC service definition, create a server, and create a client. This architecture is highly scalable and resilient and provides a robust and performant solution for organizations looking to modernize their applications.