🚀 API Monitoring System

🌟 Introduction

What is API Monitoring System?

API Monitoring System is a professional, self-hosted solution that monitors your APIs, websites, and web services 24/7. It provides real-time monitoring, instant email alerts, comprehensive metrics, and a beautiful mobile-first admin panel.

💻 System Requirements

Minimum Requirements

Supported Platforms

• ✅ Shared Hosting - cPanel, Plesk
• ✅ VPS - Ubuntu, Debian, CentOS, RHEL
• ✅ Cloud - AWS, DigitalOcean, Linode, Vultr
• ✅ Dedicated Servers - Linux, Windows
• ✅ Docker - Containers supported

✅ Pre-Installation Checklist

Before starting installation, ensure you have:

• FTP/SFTP credentials or File Manager access
• SSH access (VPS) or cPanel access
• Domain or subdomain configured
• SSL certificate (recommended)
• SMTP email credentials (Gmail, Outlook, or custom)
• PHP 8.1+ verified
• Required PHP extensions installed

Quick PHP Version Check

# Run this command:
php -v

# Should show: PHP 8.1.0 or higher

Quick Extensions Check

# Check installed extensions:
php -m | grep -E 'curl|json|openssl|mbstring'

# All should be listed

🎛️ cPanel Installation (Shared Hosting)

Perfect for shared hosting with cPanel access. This is the easiest method for most users.

🖥️ VPS Installation (Ubuntu/Debian)

For VPS servers running Ubuntu 20.04+ or Debian 10+.

Step 1: Connect to VPS

ssh root@your-server-ip
# Or with regular user:
ssh username@your-server-ip

Step 2: Update System

sudo apt update
sudo apt upgrade -y

Step 3: Install PHP 8.1+

# Add PHP repository
sudo apt install software-properties-common -y
sudo add-apt-repository ppa:ondrej/php -y
sudo apt update

# Install PHP and extensions
sudo apt install php8.1 php8.1-cli php8.1-curl \
  php8.1-mbstring php8.1-xml php8.1-zip -y

# Verify
php -v

Step 4: Install Web Server

Option A: Apache

sudo apt install apache2 libapache2-mod-php8.1 -y
sudo systemctl start apache2
sudo systemctl enable apache2

Option B: Nginx + PHP-FPM

sudo apt install nginx php8.1-fpm -y
sudo systemctl start nginx php8.1-fpm
sudo systemctl enable nginx php8.1-fpm

Step 5: Create Directory and Upload Files

# Create directory
sudo mkdir -p /var/www/html/monitoring

# Upload via SCP (from your computer)
scp api-monitoring-v1.0.0.zip user@server:/tmp/

# Extract on server
sudo unzip /tmp/api-monitoring-v1.0.0.zip -d /var/www/html/monitoring/

Step 6: Set Permissions

cd /var/www/html/monitoring

# Set ownership
sudo chown -R www-data:www-data .

# Use auto-fix script
sudo -u www-data php setup_permissions.php

# Or manually:
sudo chmod 666 config.json.example
sudo chmod 755 data
sudo chmod 666 data/*.json

Step 7: Configure Apache Virtual Host

sudo nano /etc/apache2/sites-available/monitoring.conf

Add this configuration:

<VirtualHost *:80>
    ServerName monitor.yourdomain.com
    DocumentRoot /var/www/html/monitoring
    
    <Directory /var/www/html/monitoring>
        Options -Indexes +FollowSymLinks
        AllowOverride All
        Require all granted
    </Directory>
</VirtualHost>

Enable site and reload:

sudo a2ensite monitoring.conf
sudo a2enmod rewrite
sudo systemctl reload apache2

Step 8: Install SSL (Recommended)

# Install Certbot
sudo apt install certbot python3-certbot-apache -y

# Get certificate
sudo certbot --apache -d monitor.yourdomain.com

Step 9: Run Installation Wizard

Open browser: http://monitor.yourdomain.com/install.php

Step 10: Set Up Cron Job

# Edit crontab for web server user
sudo crontab -u www-data -e

# Add this line (runs every 5 minutes):
*/5 * * * * cd /var/www/html/monitoring && php cron.php >> /dev/null 2>&1

🖥️ VPS Installation (CentOS/RHEL)

For VPS servers running CentOS 8+ or RHEL 8+.

Install PHP 8.1+

# Enable repositories
sudo dnf install epel-release -y
sudo dnf install https://rpms.remirepo.net/enterprise/remi-release-8.rpm -y

# Enable PHP 8.1
sudo dnf module reset php -y
sudo dnf module enable php:remi-8.1 -y

# Install PHP and extensions
sudo dnf install php php-cli php-curl php-mbstring \
  php-xml php-zip php-json -y

# Verify
php -v

Install Apache

sudo dnf install httpd -y
sudo systemctl start httpd
sudo systemctl enable httpd

Configure Firewall

sudo firewall-cmd --permanent --add-service=http
sudo firewall-cmd --permanent --add-service=https
sudo firewall-cmd --reload

Follow similar steps as Ubuntu for file upload, permissions, and configuration.

🧙 Web-Based Installation Wizard

The installation wizard automates the entire setup process. Simply access http://yourdomain.com/install.php and follow these 6 steps:

Step 1: System Requirements Check

The wizard checks:

• ✅ PHP version (8.1+ required)
• ✅ Required PHP extensions
• ✅ File permissions
• ✅ Directory structure

Step 2: System Configuration

Step 3: Email Configuration

Gmail SMTP Setup:

• SMTP Host: smtp.gmail.com
• SMTP Port: 587
• Encryption: TLS
• Username: Your Gmail address
• Password: App-specific password (not regular password)

Outlook SMTP Setup:

• SMTP Host: smtp-mail.outlook.com
• SMTP Port: 587
• Encryption: TLS

Step 4: First API Endpoint (Optional)

Add your first endpoint to monitor:

• Name: Descriptive name (e.g., "Main Website")
• URL: Full URL (e.g., https://api.example.com/health)
• Method: Select from 7 HTTP methods (GET is most common)
• Expected Text: Optional text to find in response

Step 5: Admin Credentials

Create your admin account for the admin panel.

Step 6: Complete Installation

Review summary and click "Complete Installation". The wizard will:

• Create configuration file
• Initialize data files
• Test settings
• Delete install.php (security)

⚙️ Manual Configuration

If you prefer manual setup or the wizard isn't working:

Create Configuration File

cp config.json.example config.json
nano config.json

Basic Configuration Example

{
    "timezone": "America/New_York",
    "system_name": "My API Monitor",
    "monitoring_interval": 300,
    
    "email": {
        "smtp_host": "smtp.gmail.com",
        "smtp_port": 587,
        "smtp_username": "[email protected]",
        "smtp_password": "your-app-password",
        "smtp_encryption": "tls",
        "from_email": "[email protected]",
        "from_name": "API Monitoring",
        "to_email": "[email protected]"
    },
    
    "endpoints": {
        "Main API": {
            "url": "https://api.example.com/health",
            "method": "GET",
            "timeout": 30,
            "max_retries": 3,
            "expected_text": "ok",
            "headers": [],
            "post_data": null
        }
    }
}

Set Permissions

chmod 666 config.json
chmod 755 data
chmod 666 data/*.json
touch api_monitor.log
chmod 666 api_monitor.log

Test Configuration

# Validate config
php validate_config.php

# Test monitoring
php cron.php

# Check logs
tail api_monitor.log

⏰ Setting Up Cron Jobs

Cron jobs automate the monitoring process. The system needs to run cron.php periodically.

cPanel Cron Setup

1. Login to cPanel
2. Go to "Cron Jobs"
3. Common Settings: Select "Every 5 minutes"
4. Command:

cd /home/username/public_html/monitoring && php cron.php >> /dev/null 2>&1

Or with full PHP path:

/usr/bin/php /home/username/public_html/monitoring/cron.php >> /dev/null 2>&1

VPS/Linux Cron Setup

# Edit crontab for web server user
sudo crontab -u www-data -e

# Add this line (every 5 minutes):
*/5 * * * * cd /var/www/html/monitoring && php cron.php >> /dev/null 2>&1

Different Intervals

Verify Cron is Running

# List cron jobs
crontab -l

# Check application logs
tail -f api_monitor.log

# Should see entries every 5 minutes

🎛️ Using the Admin Panel

Access: http://yourdomain.com/admin/

Dashboard Page

Overview of your monitoring system:

• Metrics Cards: Total uptime, average response time, success rate
• Activity Log: Recent monitoring events
• Quick Actions: Test endpoint, view logs, configure
• Endpoint Status: Visual status of all endpoints

API Endpoints Page

Adding New Endpoint

1. Click "Add New Endpoint"
2. Fill in details:
   • Name: Descriptive identifier
   • URL: Full URL with https://
   • Method: Select from 7 HTTP methods
   • Timeout: 5-120 seconds
   • Max Retries: 1-10 attempts
   • Expected Text: Optional validation
   • Headers: One per line (optional)
   • Request Body: For POST/PUT/PATCH (auto shows/hides)
3. Click "Test Endpoint" to verify before saving
4. Click "Add Endpoint" to save

HTTP Methods Explained

Configuration Page

Email Testing (AJAX)

1. Scroll to "Test Email Configuration"
2. Enter test email address
3. Select type:
   • Simple Test - Basic email
   • UP Alert - Service restored (fake data)
   • DOWN Alert - Service down (fake data)
4. Click "Send Test Email"
5. See result instantly (no page refresh)
6. Check inbox and spam folder

Cron Job Setup Guide

The page automatically detects your PHP path and provides copy-paste cron commands for:

• Linux/macOS (crontab)
• cPanel
• Windows Task Scheduler

System Check Page

Comprehensive diagnostics with one-click fixes:

Auto-Fix Features:

• 🔧 Install PHPMailer - One-click installation
  • Tries 4 different methods
  • Detailed error reporting if fails
  • Manual instructions provided
• 🔧 Fix Permissions - Automatically sets correct chmod values
• 🔧 Create Missing Files - Generates required data files

Logs Page

View, download, and manage logs:

• Pagination (50 entries per page)
• Log statistics dashboard
• Download logs button
• Clear logs button
• Auto-refresh option

Mobile Navigation

On mobile devices:

• ☰ Hamburger menu in top-left
• Tap to open/close sidebar
• Touch-friendly 44px buttons
• Optimized font sizes
• Perfect on all screen sizes

🔒 Security Hardening

Essential steps to secure your installation after setup.

1. Delete Install File

# Via SSH:
rm install.php

# Via cPanel: Delete install.php in File Manager

2. Secure Admin Panel

Method A: Password Protection (.htaccess)

# Create password file
htpasswd -c /path/to/.htpasswd admin

# Edit admin/.htaccess and add:
AuthType Basic
AuthName "Admin Panel Access"
AuthUserFile /full/path/to/.htpasswd
Require valid-user

Method B: IP Restriction

# Edit admin/.htaccess and add:
Order deny,allow
Deny from all
Allow from YOUR_IP_ADDRESS
Allow from YOUR_OFFICE_IP

Method C: Rename Admin Directory

mv admin my-secret-admin-xyz
# Access via: http://yourdomain.com/my-secret-admin-xyz/

3. Enable HTTPS (SSL)

# Free SSL with Let's Encrypt
sudo apt install certbot python3-certbot-apache -y
sudo certbot --apache -d monitor.yourdomain.com

Force HTTPS redirect in .htaccess:

RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

4. Protect Configuration File

# After setup, make read-only
chmod 444 config.json

# When need to edit:
chmod 644 config.json
# ... make changes ...
chmod 444 config.json

5. Configure Firewall (VPS)

# UFW (Ubuntu/Debian)
sudo ufw enable
sudo ufw allow 22    # SSH
sudo ufw allow 80    # HTTP
sudo ufw allow 443   # HTTPS

# Firewalld (CentOS/RHEL)
sudo firewall-cmd --permanent --add-service=http
sudo firewall-cmd --permanent --add-service=https
sudo firewall-cmd --reload

6. Change Admin Password

After first login:

1. Use a password manager
2. Create strong, unique password (12+ characters)
3. Mix uppercase, lowercase, numbers, symbols
4. Never share password

Security Checklist

• install.php deleted
• HTTPS enabled
• Admin password strong and unique
• File permissions correct (666/755)
• Data directory protected (.htaccess)
• Firewall configured (VPS)
• Regular backups scheduled
• Log monitoring enabled

⚡ Post-Installation Configuration

1. Add More Endpoints

Prioritize by importance:

1. Critical - Payment gateways, authentication (check every 1-5 min)
2. Important - Main services, databases (check every 5-10 min)
3. Standard - General endpoints (check every 10-15 min)
4. Low Priority - Non-critical APIs (check every 15-30 min)

2. Configure Response Validation

For each endpoint, set "Expected Text" to verify correct response:

• "status":"ok" - JSON response
• "healthy":true - Health check
• success - Simple text
• running - Service status

3. Test Email Alerts

1. Go to Configuration → Test Email
2. Send all 3 types (Simple, UP, DOWN)
3. Verify emails arrive
4. Check spam folder
5. Whitelist sender email

4. Set Up Regular Backups

# Weekly backup (Sundays at 2 AM)
0 2 * * 0 cd /var/www/html/monitoring && php backup_data.php

5. Monitor the Monitor

• Check dashboard daily (first week)
• Review logs weekly
• Verify email delivery
• Check cron is running
• Monitor disk space

💾 Backup & Maintenance

Automated Backups

# Run included backup script
php backup_data.php

# Creates: backup-YYYYMMDD-HHMMSS.tar.gz
# Contains: config.json, data/*.json, logs

Manual Backup

# Full backup (VPS)
tar -czf monitoring-backup-$(date +%Y%m%d).tar.gz \
  config.json data/ api_monitor.log

# Download
scp user@server:/path/to/monitoring-backup-*.tar.gz ./

Restore from Backup

# Extract
tar -xzf backup-YYYYMMDD-HHMMSS.tar.gz

# Restore files
cp backup/config.json config.json
cp backup/data/*.json data/

# Set permissions
chmod 666 config.json data/*.json

Regular Maintenance

🔧 Troubleshooting

Common Issues

Issue: Email alerts not sending

Solutions:

1. Test email in Configuration page
2. Check SMTP credentials are correct
3. For Gmail: Use App Password (not regular password)
4. Check spam folder
5. Verify PHPMailer installed (System Check page)
6. Check logs: tail api_monitor.log

Issue: Permission denied errors

# Quick fix
php setup_permissions.php

# Or manually
chmod 666 config.json data/*.json api_monitor.log
chmod 755 data

Issue: Cron not running

# Check cron service
sudo systemctl status cron   # Ubuntu
sudo systemctl status crond  # CentOS

# List cron jobs
crontab -l

# Test manually
php cron.php

Issue: Metrics showing 0ms

Cause: cURL or OpenSSL not installed

# Install extensions
sudo apt install php8.1-curl php8.1-openssl
sudo systemctl restart apache2

Issue: Admin panel not responsive on mobile

Solutions:

• Clear browser cache
• Hard refresh: Ctrl+F5 (Windows) or Cmd+Shift+R (Mac)
• Try different browser
• Check console for errors (F12)

❓ Frequently Asked Questions

General Questions

Q: Do I need a database?

A: No! Uses JSON files for storage. Easy to deploy, backup, and migrate.

Q: Can I monitor unlimited endpoints?

A: Yes! No artificial limits. Successfully tested with 100+ endpoints.

Q: Does it support all HTTP methods?

A: Yes! All 7 methods (GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS) with smart request body handling.

Q: Will it work on shared hosting?

A: Yes! As long as you have PHP 8.1+ and cron access. Auto-fix handles common issues.

Q: Is it really mobile-first?

A: Yes! Fully responsive with touch-friendly interface, collapsible sidebar, optimized for all screen sizes.

Installation Questions

Q: How long does installation take?

A: 5-10 minutes with web wizard. Manual installation: 15-30 minutes.

Q: Can I install in a subdirectory?

A: Yes! Install anywhere: root, subdirectory, or subdomain.

Q: Do I need SSH access?

A: No for cPanel. SSH helpful for VPS but not required.

Email Questions

Q: Why aren't emails sending?

A: Common causes:

1. Wrong SMTP credentials
2. Port 587 blocked by firewall
3. Gmail: Using regular password instead of app password
4. PHPMailer not installed (use auto-fix)
5. Emails in spam folder

Q: Can I use free Gmail?

A: Yes! Enable 2FA and generate App Password.

Q: Can I send to multiple recipients?

A: Yes! Comma-separated: [email protected], [email protected]

Security Questions

Q: Is it secure?

A: Yes! Multiple security layers: .htaccess protection, password hashing, input validation, XSS prevention.

Q: Should I use HTTPS?

A: Yes, highly recommended! Free SSL with Let's Encrypt.

Q: Can I restrict admin access by IP?

A: Yes! Edit admin/.htaccess with IP restrictions.

⚡ Quick Reference

Essential Commands

# Installation
cp config.json.example config.json
php setup_permissions.php

# Test monitoring
php cron.php

# View logs
tail -f api_monitor.log

# Backup data
php backup_data.php

# Validate config
php validate_config.php

File Locations

Default URLs

• Installation: http://yourdomain.com/install.php
• Admin Panel: http://yourdomain.com/admin/
• Landing Page: http://yourdomain.com/

📞 Support & Resources

🎉 Congratulations!

You're now ready to monitor your APIs 24/7 with confidence!

Next Steps:

1. ✅ Add your critical API endpoints
2. ✅ Set up email alerts and test them
3. ✅ Configure cron job
4. ✅ Wait 5 minutes and check Dashboard
5. ✅ Secure your installation
6. ✅ Set up regular backups