Bank-Pro 🏦

A robust, production-ready backend banking service built with Go, featuring account management, user authentication, secure token handling, and comprehensive database operations.

🌟 Features

• User Management: Create and manage bank accounts with secure authentication
• JWT & PASETO Authentication: Dual token generation for enhanced security
• Account Operations: Core banking functionalities for account management
• Transfer & Transactions: Secure fund transfer and transaction tracking
• PostgreSQL Database: Reliable data persistence with connection pooling
• REST API: Clean, RESTful endpoints powered by Gin framework
• Input Validation: Comprehensive request validation using go-playground/validator
• Unit Testing: Full test coverage with mocking support
• Docker Support: Easy deployment with Docker and Docker Compose
• Database Migrations: Version-controlled schema management with SQL migrations

🛠️ Tech Stack

Component	Technology	Purpose
Language	Go 1.25.5	Fast, efficient backend development
Web Framework	Gin	High-performance HTTP framework
Database	PostgreSQL 16	Reliable relational database
DB Driver	pgx/v5	Modern PostgreSQL driver
DB Generation	sqlc	Type-safe SQL queries
Authentication	JWT + PASETO	Secure token-based auth
Validation	go-playground/validator	Request validation
Config Management	Viper	Environment configuration
Containerization	Docker & Docker Compose	Deployment orchestration
Testing	testify + uber/mock	Testing & mocking utilities

📋 Project Structure

Bank-Pro/
├── main.go                 # Application entry point
├── go.mod & go.sum        # Go dependencies
├── Dockerfile             # Container image definition
├── docker-compose.yaml    # Multi-container setup
├── Makefile              # Common development commands
├── sqlc.yaml             # SQL code generation config
├── app.env               # Environment variables
│
├── api/                  # REST API handlers & server
├── db/                   # Database layer
│   ├── migration/        # SQL migration files
│   ├── sqlc/            # Generated SQL queries
│   └── mock/            # Mock database for testing
├── token/               # JWT & PASETO token management
└── util/                # Utility functions & helpers

🚀 Quick Start

Prerequisites

• Go 1.25.5 or higher
• Docker & Docker Compose
• PostgreSQL client (optional, for local development)

Setup & Run

Option 1: Using Docker Compose (Recommended)

# Clone the repository
git clone https://github.com/niloy104/Bank-Pro.git
cd Bank-Pro

# Start services
docker-compose up --build

# API will be available at http://localhost:8080

Option 2: Local Development

# Clone repository
git clone https://github.com/niloy104/Bank-Pro.git
cd Bank-Pro

# Start PostgreSQL
make postgres

# Create database
make createdb

# Run migrations
make migrateup

# Start server
make server

# API will be running at configured SERVER_ADDRESS

📦 Available Make Commands

# Database operations
make postgres              # Start PostgreSQL container
make createdb             # Create 'simple_bank' database
make dropdb               # Drop 'simple_bank' database

# Database migrations
make migrateup            # Run all pending migrations
make migratedown          # Rollback all migrations
make migrateup1           # Run next 1 migration
make migratedown1         # Rollback 1 migration

# Code generation & testing
make sqlc                 # Generate type-safe SQL code
make test                 # Run all tests with coverage
make mock                 # Generate mock database for tests

# Development
make server               # Start the API server

⚙️ Configuration

Configuration is managed via environment variables. Create an app.env file:

# Server Configuration
SERVER_ADDRESS=0.0.0.0:8080

# Database Configuration
DB_SOURCE=postgresql://root:secret@localhost:5432/simple_bank?sslmode=disable

# JWT/PASETO Configuration
TOKEN_SYMMETRIC_KEY=<your-32-character-key>
ACCESS_TOKEN_DURATION=15m
REFRESH_TOKEN_DURATION=24h

🔌 API Endpoints

Authentication

• POST /auth/login - User login (returns JWT/PASETO token)
• POST /auth/refresh - Refresh authentication token

Accounts

• POST /accounts - Create new account
• GET /accounts/:id - Get account details
• GET /accounts - List user accounts

Transfers

• POST /transfers - Create fund transfer
• GET /transfers/:id - Get transfer details

Transactions

• GET /transactions - List account transactions

Detailed API documentation available in /api endpoint

🧪 Testing

# Run all tests
make test

# Run specific test
go test -v ./api

# Run with coverage report
go test -cover ./...

Tests use mock databases and dependency injection for isolated, reliable testing.

📦 Build & Deployment

Build Docker Image

# Build image
docker build -t bank-pro:latest .

# Run container
docker run -p 8080:8080 \
  -e DB_SOURCE=postgresql://root:secret@postgres:5432/simple_bank \
  bank-pro:latest

Deploy with Docker Compose

docker-compose up -d

🔐 Security Features

• Token-Based Authentication: JWT and PASETO tokens
• Password Encryption: Secure hashing with golang.org/x/crypto
• SQL Injection Prevention: Type-safe queries via sqlc
• Input Validation: Comprehensive request validation
• Environment-Based Config: Sensitive data in environment variables
• Connection Pooling: Secure database connection management via pgxpool

📚 Dependencies

Key external dependencies:

• github.com/gin-gonic/gin - Web framework
• github.com/golang-jwt/jwt/v5 - JWT token generation
• github.com/o1egl/paseto - PASETO token generation
• github.com/jackc/pgx/v5 - PostgreSQL driver
• golang.org/x/crypto - Cryptographic functions
• github.com/google/uuid - UUID generation
• github.com/spf13/viper - Configuration management

See go.mod for complete dependency list.

🤝 Development Workflow

1. Create Feature Branch: git checkout -b feature/your-feature
2. Make Changes: Implement your feature
3. Run Tests: make test - ensure all tests pass
4. Generate Code: make sqlc - if database changes
5. Commit: Commit with meaningful messages
6. Push & PR: Create pull request for review

📊 Code Quality

• Type Safety: Full static typing with Go
• Testing: Comprehensive unit tests with mocking
• Linting: Go standard conventions followed
• Documentation: Inline comments for complex logic

🐛 Troubleshooting

Port Already in Use

# Change SERVER_ADDRESS in app.env
SERVER_ADDRESS=0.0.0.0:8081

Database Connection Error

# Verify PostgreSQL is running
docker ps | grep postgres

# Check DB_SOURCE connection string

Migration Issues

# Reset migrations
make migratedown
make migrateup

📄 License

This project is licensed under the terms specified in the LICENSE file.

👤 Author

niloy104 - GitHub Profile

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📈 Language Composition

• Go: 92% (Core application)
• Shell: 5.8% (Deployment scripts)
• Makefile: 1.5% (Build automation)
• Dockerfile: 0.7% (Container setup)

🌐 Resources

• Go Documentation
• Gin Framework Guide
• PostgreSQL Documentation
• Docker Documentation

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Built with ❤️ for secure, scalable banking backend systems