PingWatch

A lightweight bash-based service to continuously monitor the availability of an IP address using ping,
and execute a custom script (e.g., send SMS, email) when the status changes from UP to DOWN or vice versa.

🚀 Features

• Detects server reachability with ICMP ping
• Verifies failures with a second check after 30 seconds (to avoid false alerts)
• Triggers custom PHP script on status change
• Tracks state persistently using a temp file
• Runs in the background via systemd

📦 Files

• pingwatch.sh: Main bash script
• pingwatch.service: Example systemd service file
• send_alert.php: Your custom alert logic (not included, user-defined)

🛠️ Installation

1. Clone the repo:

   git clone https://github.com/masoudhb/pingwatch.git
   cd pingwatch

2. Edit pingwatch.sh and set your:

   • IP to monitor (e.g., IP=8.8.8.8)
   • Path to your PHP alert script

3. Make it executable:

   chmod +x pingwatch.sh

4. Create a systemd service at /etc/systemd/system/pingwatch.service:

   [Unit]
   Description=Ping Watcher Service
   After=network.target
   
   [Service]
   ExecStart=/full/path/to/pingwatch.sh
   Restart=always
   
   [Install]
   WantedBy=multi-user.target

5. Enable and start:

   sudo systemctl daemon-reexec
   sudo systemctl enable pingwatch
   sudo systemctl start pingwatch

📋 Example Output

Sat May 24 11:51:07 BST 2025: First ping failed, waiting 30s to recheck...
Sat May 24 11:51:38 BST 2025: Status changed to DOWN
Sat May 24 11:57:18 BST 2025: Status changed to UP

📄 License

MIT License — feel free to use and modify.