Process Monitoring System

This is an automatic system for Linux. It checks if your process is running and sends status to a monitoring server.

What does it do?

This project helps you monitor your processes. It can:

• 🔍 Check if process is running - it looks for your process on the system
• 📊 Save logs - it writes all checks and changes to a log file
• 🔄 Detect restarts - it knows when your process restarts (PID changes)
• 🌐 Send data to server - it sends HTTP requests to your monitoring server
• ⏰ Work automatically - it checks every minute using systemd timer

Project Files

This project has 4 files:

1. script.sh - main monitoring script that checks the process
2. test-monitoring.service - systemd service file to run the script
3. test-monitoring.timer - systemd timer file for automatic running
4. install_monitoring.sh - installation script (makes setup easy)

What you need

• OS: Linux with systemd (Ubuntu, Debian, CentOS, Fedora, etc.)
• Access: root user access for installation
• Programs:
  • bash
  • curl (for sending requests to monitoring server)
  • systemd (for automatic running)

How to Install

Step 1: Download the project

git clone <repository-url>
cd monitoring_service

Step 2: Edit settings

Before installation, open file script.sh and change these settings:

PROCESS_NAME="test"                                    # Name of your process
PROCESS_PATH="/usr/local/bin/test"                     # Full path to your process
MONITORING_URL="https://test.com/monitoring/test/api"  # URL of your monitoring server
LOG_FILE="/var/log/monitoring.log"                     # Path to log file

Step 3: Run installation

sudo ./install_monitoring.sh

The installation script will do everything for you:

• Create needed directories
• Copy monitoring script to /usr/local/bin/test-monitor.sh
• Create log file /var/log/monitoring.log
• Install systemd service and timer files
• Start the monitoring system

How to Use

Check if system is working

# Check if timer is running
sudo systemctl status test-monitoring.timer

# Check last service runs
sudo systemctl status test-monitoring.service

View logs

# View log file
sudo tail -f /var/log/monitoring.log

# View systemd logs
sudo journalctl -u test-monitoring.service -f

Control the system

# Stop monitoring
sudo systemctl stop test-monitoring.timer

# Start monitoring
sudo systemctl start test-monitoring.timer

# Restart monitoring
sudo systemctl restart test-monitoring.timer

# Disable automatic start on boot
sudo systemctl disable test-monitoring.timer

# Enable automatic start on boot
sudo systemctl enable test-monitoring.timer

Run check manually

# Run check by hand
sudo /usr/local/bin/test-monitor.sh

# Or use systemd
sudo systemctl start test-monitoring.service

How does it work?

Here is what happens:

1. Systemd Timer starts when your computer boots. It runs every minute.
2. Systemd Service runs the monitoring script each time the timer activates.
3. Monitoring Script does these things:
   • Looks for the process by name and path
   • Compares current PID with previous PID (saved in /tmp/test_monitor.pid)
   • Writes to log if process restarted (PID changed)
   • Sends HTTP request to monitoring server
   • Writes results to log file

Log Format

The logs look like this:

2025-10-25 14:30:45 - Process test restarted. Old PID: 1234, New PID: 5678
2025-10-25 14:30:45 - Successfully contacted monitoring server at https://test.com/monitoring/test/api
2025-10-25 14:31:45 - Failed to contact monitoring server at https://test.com/monitoring/test/api

How to Uninstall

If you want to remove this system:

# Stop and disable timer
sudo systemctl stop test-monitoring.timer
sudo systemctl disable test-monitoring.timer

# Delete systemd files
sudo rm /etc/systemd/system/test-monitoring.service
sudo rm /etc/systemd/system/test-monitoring.timer

# Delete script
sudo rm /usr/local/bin/test-monitor.sh

# Delete PID file
sudo rm /tmp/test_monitor.pid

# Reload systemd
sudo systemctl daemon-reload

You can keep the log file or delete it:

sudo rm /var/log/monitoring.log

Setup for Different Process

If you want to monitor a different process:

1. Edit file script.sh:

   • Change PROCESS_NAME to your process name
   • Change PROCESS_PATH to your process path
   • Change MONITORING_URL to your server URL

2. Install again:

sudo systemctl stop test-monitoring.timer
sudo ./install_monitoring.sh

Change Check Time

By default, the system checks every minute. To change this:

1. Edit file test-monitoring.timer
2. Change line OnUnitActiveSec (for example, 5min for 5 minutes)
3. Install again:

sudo cp test-monitoring.timer /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl restart test-monitoring.timer

Problems and Solutions

System does not start

# Check errors in systemd logs
sudo journalctl -xe -u test-monitoring.timer
sudo journalctl -xe -u test-monitoring.service

Cannot write to log file

If there are problems writing to /var/log/monitoring.log, the script will automatically use /tmp/monitoring.log.

Process not found

Make sure that:

• PROCESS_PATH is correct path to your process file
• Your process is really running: ps aux | grep <process_name>

Security Notes

• System runs as root user (needs this for system access)
• Log files can be read by all users (chmod 666)
• HTTP requests have no authentication (you can add it if you need)

License

This project is open-source.

Author

Dmitrii Savchenko

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📝 Important: Remember to change settings in script.sh before installation!