Transaction System - Node.js/gRPC

This is a Node.js based transaction system API built following the microservices architecture.

Table of Contents

• Transaction System - Node.js/gRPC
• Table of Contents
  • Modules
    • server
      • Dependencies
      • Running the server
    • gateway
      • Dependencies
      • Running the gateway
    • common
      • Dependencies
    • qr-socketio
      • Dependencies
      • Running the qr-socketio server
  • System Features

Modules

The project consists of the following modules:

server

The server module consists of the core logic to handle transactions.

Dependencies

• node-grpc: gRPC Server
• MySQL: Database
• Sequelize: ORM
• nodemailer: Mail Client
• bcrypt: Password Hashing
• socket.io-client: Socket.IO client

Running the server

In order to run the server, a MySQL database is required. Download and install MySQL if your system does not have it already installed. Make sure the MySQL server is running.

A configuration file is required in order for the server to work. Create a file name .env.development in the server folder with the following fields:

DB_HOST="127.0.0.1"
DB_USER="root"
DB_PASSWORD="password"
DB_NAME="transaction_db"
DB_PORT="3306"

GRPC_ADDRESS="0.0.0.0"
GRPC_PORT="50051"

SOCKETIO_ADDRESS="0.0.0.0"
SOCKETIO_PORT="3001"

ENABLE_NODEMAILER=0
NODEMAILER_EMAIL="[email protected]"
NODEMAILER_PASSWORD="mypassword"

Install all dependencies

cd server && npm install

When running for the first time

npm run init

After initialization, the server can be run with

npm start

---

gateway

The gateway module consists of a standard REST API to communicate with the server using gRPC client.

Dependencies

• express: HTTP Server
• jsonwebtoken: Handle JWT
• bcrypt: Password Hashing

Running the gateway

A configuration file is required in order for the gateway to work. Create a file name .env.development in the gateway folder with the following fields:

GRPC_ADDRESS="0.0.0.0"
GRPC_PORT="3000"

JWT_KEY="MY JWT KEY"
JWT_EXPIRY_TIME="n d"

Note: The gateway is incomplete and all functionality might not work. Consider using BloomRPC to use the server. The .proto files can be found in the common folder.

Install all dependencies

cd gateway && npm install

Start the gateway

npm start

---

common

The common module consists of files shared between two or more modules.

Dependencies

• No dependencies.

---

qr-socketio

The qr-socketio module handles QR encoding/decoding and communication between server and a demo browser client. User can create a transaction request which generates a QR code. This QR code can be scanned by other users to transfer balance from their account to the user who requested the balance.

Dependencies

• express: HTTP Server
• socket.io: Socket.IO (Websocket)
• styled-qr-code-node: QR Code generation

Running the qr-socketio server

The QR server has a web portal available at the root address.

Install all dependencies

cd qr && npm install

Start the QR server

npm start

System Features

• standard transaction features
• send and receive balance
• get transaction history
• user account creation and management
• authentication using JWT
• transaction verification through OTP
• transaction request and completion through QR code
• password hashing and encryption