HBlink4/SYSTEMD.md

HBlink4 Systemd Service Installation

This directory contains systemd service files for running HBlink4 and its dashboard as system services.

Service Files

• hblink4.service - Main HBlink4 DMR server
• hblink4-dash.service - Web dashboard (depends on hblink4.service)

Installation

1. Install the service files

Copy the service files to systemd's system directory:

sudo cp hblink4.service /etc/systemd/system/
sudo cp hblink4-dash.service /etc/systemd/system/

2. Reload systemd

Tell systemd to reload its configuration:

sudo systemctl daemon-reload

3. Enable services (optional)

To start the services automatically at boot:

sudo systemctl enable hblink4
sudo systemctl enable hblink4-dash

4. Start the services

sudo systemctl start hblink4
sudo systemctl start hblink4-dash

Service Management

Check service status

sudo systemctl status hblink4
sudo systemctl status hblink4-dash

View logs

# View logs for HBlink4
sudo journalctl -u hblink4 -f

# View logs for dashboard
sudo journalctl -u hblink4-dash -f

# View last 100 lines
sudo journalctl -u hblink4 -n 100

Stop services

sudo systemctl stop hblink4
sudo systemctl stop hblink4-dash

Restart services

sudo systemctl restart hblink4
sudo systemctl restart hblink4-dash

Disable autostart

sudo systemctl disable hblink4
sudo systemctl disable hblink4-dash

Configuration

The service files are configured to:

• Run as user cort in group cort
• Use the Python virtual environment at /home/cort/hblink4/venv
• Automatically restart on failure (after 10 seconds)
• Log to systemd journal (view with journalctl)
• Start after network is available
• Dashboard starts after and depends on HBlink4

Customization

If you need to modify the services (different user, paths, etc.), edit the files before copying them:

1. Edit hblink4.service and/or hblink4-dash.service
2. Change User=, Group=, WorkingDirectory=, or ExecStart= as needed
3. Copy to /etc/systemd/system/
4. Run sudo systemctl daemon-reload

Security Features

Both services include security hardening:

• NoNewPrivileges=true - Prevents privilege escalation
• PrivateTmp=true - Isolates /tmp directory

Troubleshooting

Service won't start

Check the status and logs:

sudo systemctl status hblink4
sudo journalctl -u hblink4 -n 50

Common issues:

• Virtual environment not found: Check path in ExecStart=
• Permission errors: Ensure user/group are correct
• Config file errors: Check HBlink4 configuration files
• Port conflicts: Another service using the same ports

Dashboard can't connect to HBlink4

1. Ensure HBlink4 is running: sudo systemctl status hblink4
2. Check dashboard config points to correct socket/host
3. Check logs: sudo journalctl -u hblink4-dash -n 50

Notes

• The dashboard service has Wants=hblink4.service, so it will start after HBlink4
• Both services have Restart=always for automatic recovery
• Logs are sent to systemd journal, not file-based logging
• Services run with the same privileges as the cort user