Configuration Guide

The Sales Management System API uses a centralized configuration file for all environment-specific settings.

Configuration File

The main configuration is located at src/config.js:

export default {
    PORT: 3000,
    HOST_DATABASE: "localhost",
    PORT_DATABASE: 3306,
    DATABASE_NAME: "erpDB",
    PASSWORD_DATABASE: "admin",
    USER_DATABASE: "root"
}

Configuration Parameters

Server Configuration

PORT

The port on which the Express server listens.

Type: number
Default: 3000
Example: PORT: 8080

Usage in code:

app.listen(config.PORT, (err) => {
    if (err) console.log(err)
    else {
        console.log(`Server on port http://localhost:${config.PORT}`)
    }
})

If port 3000 is already in use, change this to an available port like 3001 or 8080.

Database Configuration

HOST_DATABASE

MySQL server hostname or IP address.

Type: string
Default: "localhost"
Examples:
- Local: "localhost" or "127.0.0.1"
- Remote: "db.example.com" or "192.168.1.100"

PORT_DATABASE

MySQL server port.

Type: number
Default: 3306
Example: PORT_DATABASE: 3307 (for non-standard MySQL port)

DATABASE_NAME

Name of the MySQL database.

Type: string
Default: "erpDB"
Example: DATABASE_NAME: "sales_system"

Ensure this database exists before starting the application. Create it with:

CREATE DATABASE erpDB;

USER_DATABASE

MySQL username for authentication.

Type: string
Default: "root"
Example: USER_DATABASE: "sales_api_user"

Best practice: Create a dedicated user with limited privileges:

CREATE USER 'sales_api_user'@'localhost' IDENTIFIED BY 'secure_password';
GRANT SELECT, INSERT, UPDATE, DELETE ON erpDB.* TO 'sales_api_user'@'localhost';
FLUSH PRIVILEGES;

PASSWORD_DATABASE

MySQL password for authentication.

Type: string
Default: "admin"
Example: PASSWORD_DATABASE: "my_secure_password_123"

NEVER commit passwords to version control! Use environment variables in production (see below).

Environment Variables (Recommended)

For production and team environments, use environment variables instead of hardcoded values.

Setup

Install dotenv (optional):

npm install dotenv

Create .env file:

# Server Configuration
PORT=3000

# Database Configuration
DB_HOST=localhost
DB_PORT=3306
DB_NAME=erpDB
DB_USER=root
DB_PASSWORD=admin

Update config.js:

import dotenv from 'dotenv';
dotenv.config();

export default {
    PORT: parseInt(process.env.PORT) || 3000,
    HOST_DATABASE: process.env.DB_HOST || "localhost",
    PORT_DATABASE: parseInt(process.env.DB_PORT) || 3306,
    DATABASE_NAME: process.env.DB_NAME || "erpDB",
    PASSWORD_DATABASE: process.env.DB_PASSWORD || "admin",
    USER_DATABASE: process.env.DB_USER || "root"
}

Add .env to .gitignore:

echo ".env" >> .gitignore

System Environment Variables

Alternatively, set environment variables at the system level: Linux/macOS:

export PORT=3000
export DB_HOST=localhost
export DB_PORT=3306
export DB_NAME=erpDB
export DB_USER=root
export DB_PASSWORD=admin

npm run dev

Windows (CMD):

set PORT=3000
set DB_HOST=localhost
set DB_PORT=3306
set DB_NAME=erpDB
set DB_USER=root
set DB_PASSWORD=admin

npm run dev

Windows (PowerShell):

$env:PORT=3000
$env:DB_HOST="localhost"
$env:DB_PORT=3306
$env:DB_NAME="erpDB"
$env:DB_USER="root"
$env:DB_PASSWORD="admin"

npm run dev

Connection Pool Configuration

The database connection pool is configured in src/model/pool.js:

import { createPool } from 'mysql2/promise';
import config from '../config.js';

export const pool = createPool({
    host: config.HOST_DATABASE,
    port: config.PORT_DATABASE,
    database: config.DATABASE_NAME,
    user: config.USER_DATABASE,
    password: config.PASSWORD_DATABASE
});

Advanced Pool Options

You can extend the pool configuration with additional options:

export const pool = createPool({
    host: config.HOST_DATABASE,
    port: config.PORT_DATABASE,
    database: config.DATABASE_NAME,
    user: config.USER_DATABASE,
    password: config.PASSWORD_DATABASE,
    
    // Connection pool settings
    connectionLimit: 10,        // Max connections in pool
    queueLimit: 0,             // No limit on queued requests
    waitForConnections: true,   // Wait for available connection
    
    // Connection timeouts
    connectTimeout: 10000,      // 10 seconds
    acquireTimeout: 10000,      // 10 seconds
    
    // Timezone
    timezone: 'Z',             // UTC
    
    // Character set
    charset: 'utf8mb4'         // Full Unicode support
});

Pool Configuration Options

Option	Type	Default	Description
`connectionLimit`	number	10	Maximum connections in pool
`queueLimit`	number	0	Max queued connection requests (0 = unlimited)
`waitForConnections`	boolean	true	Wait for connection when pool is full
`connectTimeout`	number	10000	Milliseconds before connection timeout
`acquireTimeout`	number	10000	Milliseconds before acquire timeout
`timezone`	string	’local’	Timezone for MySQL TIMESTAMP columns
`charset`	string	’UTF8_GENERAL_CI’	Character set for connection

Environment-Specific Configurations

Development

export default {
    PORT: 3000,
    HOST_DATABASE: "localhost",
    PORT_DATABASE: 3306,
    DATABASE_NAME: "erpDB_dev",
    PASSWORD_DATABASE: "dev_password",
    USER_DATABASE: "dev_user"
}

Testing

export default {
    PORT: 3001,
    HOST_DATABASE: "localhost",
    PORT_DATABASE: 3306,
    DATABASE_NAME: "erpDB_test",
    PASSWORD_DATABASE: "test_password",
    USER_DATABASE: "test_user"
}

Production

export default {
    PORT: process.env.PORT || 80,
    HOST_DATABASE: process.env.DB_HOST,
    PORT_DATABASE: parseInt(process.env.DB_PORT),
    DATABASE_NAME: process.env.DB_NAME,
    PASSWORD_DATABASE: process.env.DB_PASSWORD,
    USER_DATABASE: process.env.DB_USER
}

In production:

Always use environment variables
Use strong passwords
Restrict database user privileges
Use SSL/TLS for database connections
Never expose config.js with credentials

Configuration Validation

Add validation to ensure all required config values are present:

const config = {
    PORT: parseInt(process.env.PORT) || 3000,
    HOST_DATABASE: process.env.DB_HOST || "localhost",
    PORT_DATABASE: parseInt(process.env.DB_PORT) || 3306,
    DATABASE_NAME: process.env.DB_NAME || "erpDB",
    PASSWORD_DATABASE: process.env.DB_PASSWORD,
    USER_DATABASE: process.env.DB_USER || "root"
};

// Validate required fields
if (!config.DATABASE_NAME) {
    throw new Error("DATABASE_NAME is required");
}

if (!config.PASSWORD_DATABASE) {
    console.warn("WARNING: Using default password. Set DB_PASSWORD environment variable.");
}

export default config;

Troubleshooting

Cannot connect to MySQL

Check:

MySQL service is running: sudo systemctl status mysql
Host and port are correct
Firewall allows connection on port 3306
MySQL is listening on the correct interface:
```
SHOW VARIABLES LIKE 'bind_address';
```

Access denied for user

Check:

Username and password are correct
User has permissions on the database:
```
SHOW GRANTS FOR 'root'@'localhost';
```
User exists:
```
SELECT User, Host FROM mysql.user;
```

Unknown database error

Solution: Create the database:

CREATE DATABASE erpDB;

Or check the database name:

SHOW DATABASES;

Port already in use

Solutions:

Change PORT in config.js to a different value (e.g., 3001)

Find and kill the process using the port:

# Linux/macOS
lsof -ti:3000 | xargs kill -9

# Windows
netstat -ano | findstr :3000
taskkill /PID <PID> /F

Security Best Practices

Use Environment Variables

Never hardcode credentials in config.js for production environments.

Create Dedicated Database User

Don’t use the root user. Create a user with minimal required privileges:

CREATE USER 'api_user'@'localhost' IDENTIFIED BY 'strong_password';
GRANT SELECT, INSERT, UPDATE, DELETE ON erpDB.* TO 'api_user'@'localhost';

Use Strong Passwords

Generate secure passwords with at least 16 characters including uppercase, lowercase, numbers, and symbols.

Restrict Database Access

Only allow connections from trusted hosts:

CREATE USER 'api_user'@'192.168.1.100' IDENTIFIED BY 'password';

Enable SSL/TLS

For production, configure MySQL to use SSL/TLS connections:

export const pool = createPool({
    // ... other config
    ssl: {
        ca: fs.readFileSync('/path/to/ca.pem')
    }
});

Next Steps

Installation

Complete installation guide

Architecture

Learn how configuration is used

Database Schema

Understand the database structure

Error Handling

Handle connection errors

Get Started

Core Concepts

Guides

Configuration

Configuration Guide

Configuration File

Configuration Parameters

Server Configuration

PORT

Database Configuration

HOST_DATABASE

PORT_DATABASE

DATABASE_NAME

USER_DATABASE

PASSWORD_DATABASE

Environment Variables (Recommended)

Setup

System Environment Variables

Connection Pool Configuration

Advanced Pool Options

Pool Configuration Options

Environment-Specific Configurations

Development

Testing

Production

Configuration Validation

Troubleshooting

Security Best Practices

Next Steps

Installation

Architecture

Database Schema

Error Handling

Build docs developers (and LLMs) love

Get Started

Core Concepts

Guides

Documentation Index

​Configuration Guide

​Configuration File

​Configuration Parameters

​Server Configuration

​PORT

​Database Configuration

​HOST_DATABASE

​PORT_DATABASE

​DATABASE_NAME

​USER_DATABASE

​PASSWORD_DATABASE

​Environment Variables (Recommended)

​Setup

​System Environment Variables

​Connection Pool Configuration

​Advanced Pool Options

​Pool Configuration Options

​Environment-Specific Configurations

​Development

​Testing

​Production

​Configuration Validation

​Troubleshooting

​Security Best Practices

​Next Steps

Installation

Architecture

Database Schema

Error Handling

Build docs developers (and LLMs) love

Configuration Guide

Configuration File

Configuration Parameters

Server Configuration

PORT

Database Configuration

HOST_DATABASE

PORT_DATABASE

DATABASE_NAME

USER_DATABASE

PASSWORD_DATABASE

Environment Variables (Recommended)

Setup

System Environment Variables

Connection Pool Configuration

Advanced Pool Options

Pool Configuration Options

Environment-Specific Configurations

Development

Testing

Production

Configuration Validation

Troubleshooting

Security Best Practices

Next Steps