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Overview

Mis Compras uses different environment configurations for its PHP and Node.js backends. This guide covers the essential environment variables and configuration settings required for each component.

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PHP Backend Configuration

The PHP backend uses a conexion.php file for database configuration instead of traditional .env files.

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Database Connection File

Create or modify conexion.php in your PHP root directory:
conexion.php
<?php
$servername = "127.0.0.1";
$username = "root";
$password = "";
$database = "tienda_online";
$port = 522; 

// Crear conexión
$conn = new mysqli($servername, $username, $password, $database, $port);

// Verificar conexión
if ($conn->connect_error) {
    die("Error de conexión: " . $conn->connect_error);
}
?>

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PHP Configuration Variables

VariableDefault ValueDescription
$servername127.0.0.1MySQL server host address
$usernamerootDatabase user with access privileges
$password""Database password (empty for development)
$databasetienda_onlineTarget database name
$port522MySQL server port
The default port 522 is non-standard. Most MySQL installations use port 3306. Verify your MySQL configuration and adjust accordingly.

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PHP Environment Setup

1

Configure Database Connection

Update conexion.php with your local MySQL credentials:
$servername = "127.0.0.1";  // or "localhost"
$username = "your_db_user";
$password = "your_db_password";
$database = "tienda_online";
$port = 3306;  // standard MySQL port
2

Verify PHP Configuration

Check your php.ini settings for MySQL support:
extension=mysqli
extension=pdo_mysql
3

Test Connection

Create a test file to verify database connectivity:
test_connection.php
<?php
include 'conexion.php';

if ($conn->ping()) {
    echo "Database connection successful!";
} else {
    echo "Database connection failed: " . $conn->error;
}

$conn->close();
?>

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Node.js Backend Configuration

The Node.js backend uses db.js for database configuration and server.js for application settings.

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Database Configuration

The db.js file configures the MySQL connection pool:
bakend/db.js
import mysql from "mysql2/promise";

export const db = await mysql.createPool({
  host: "localhost",
  user: "root",
  password: "",
  database: "tienda_online",
  waitForConnections: true,
  connectionLimit: 10,
  queueLimit: 0,
});

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Server Configuration

The server.js file defines the application port:
bakend/server.js
const PORT = 4000; // Backend server port

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Node.js Configuration Variables

VariableDefault ValueDescription
hostlocalhostMySQL server hostname
userrootDatabase username
password""Database password
databasetienda_onlineDatabase name
connectionLimit10Maximum concurrent connections
PORT4000Express server port
For better security and flexibility, create a .env file in the bakend/ directory: 
# Database Configuration
DB_HOST=localhost
DB_USER=root
DB_PASSWORD=
DB_NAME=tienda_online
DB_CONNECTION_LIMIT=10

# Server Configuration
PORT=4000
NODE_ENV=development

# CORS Settings
CORS_ORIGIN=http://localhost:3000

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Updating Node.js Configuration to Use .env

Install the dotenv package: 
npm install dotenv
Update db.js to use environment variables:
bakend/db.js
import mysql from "mysql2/promise";
import dotenv from "dotenv";

dotenv.config();

export const db = await mysql.createPool({
  host: process.env.DB_HOST || "localhost",
  user: process.env.DB_USER || "root",
  password: process.env.DB_PASSWORD || "",
  database: process.env.DB_NAME || "tienda_online",
  waitForConnections: true,
  connectionLimit: parseInt(process.env.DB_CONNECTION_LIMIT) || 10,
  queueLimit: 0,
});
Update server.js:
bakend/server.js
import dotenv from "dotenv";
dotenv.config();

const PORT = process.env.PORT || 4000;

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Security Best Practices

Never commit sensitive credentials to version control. Always use .env files and add them to .gitignore.

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.gitignore Configuration

Add these lines to your .gitignore:
.gitignore
# Environment files
.env
.env.local
.env.production

# PHP configuration
conexion.php

# Backup the template
!conexion.example.php
!.env.example

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Creating Template Files

Create example configuration files for team members: 
<?php
$servername = "127.0.0.1";
$username = "your_username";
$password = "your_password";
$database = "tienda_online";
$port = 3306;

$conn = new mysqli($servername, $username, $password, $database, $port);

if ($conn->connect_error) {
    die("Error de conexión: " . $conn->connect_error);
}
?>

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Production Configuration

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PHP Production Settings

<?php
$servername = getenv('DB_HOST') ?: '127.0.0.1';
$username = getenv('DB_USER') ?: 'root';
$password = getenv('DB_PASSWORD') ?: '';
$database = getenv('DB_NAME') ?: 'tienda_online';
$port = getenv('DB_PORT') ?: 3306;

// Enable error logging instead of displaying
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);

try {
    $conn = new mysqli($servername, $username, $password, $database, $port);
    $conn->set_charset("utf8mb4");
} catch (Exception $e) {
    error_log("Database connection failed: " . $e->getMessage());
    die("Database connection error");
}
?>

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Node.js Production Settings

In production, use environment variables provided by your hosting platform (Heroku, AWS, DigitalOcean, etc.).
Update CORS configuration for production:
bakend/server.js
import cors from "cors";

const corsOptions = {
  origin: process.env.CORS_ORIGIN || "http://localhost:3000",
  credentials: true,
  optionsSuccessStatus: 200
};

app.use(cors(corsOptions));

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Environment-Specific Configuration

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Development

  • Use localhost for database host
  • Empty or simple passwords acceptable
  • Detailed error messages enabled
  • CORS allows all origins

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Staging

  • Use staging database credentials
  • Moderate security measures
  • Error logging enabled
  • CORS restricted to staging domains

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Production

  • Use production database with strong passwords
  • Maximum security measures
  • Error logging to files (not displayed)
  • CORS restricted to production domain only
  • SSL/TLS connections enforced

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Troubleshooting

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Common Issues

Port Conflicts 
# Check if port is already in use
lsof -i :4000  # Node.js
lsof -i :522   # PHP MySQL
Connection Refused
  • Verify MySQL is running
  • Check firewall settings
  • Confirm port numbers match MySQL configuration
Authentication Failed
  • Verify username and password
  • Check MySQL user privileges
  • Ensure password is properly escaped

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Next Steps

After configuring environment variables:
  1. Set up the PHP backend
  2. Set up the Node.js backend
  3. Test database connectivity

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