NUPST is a command-line tool that monitors SNMP-enabled UPS devices and initiates system shutdown when power outages are detected and battery levels are low.
NUPST checks for updates automatically and will notify you when an update is available. To update to the latest version:
```bash
sudo nupst update
```
This will:
1. Pull the latest changes from the git repository
2. Run the installation scripts
3. Refresh the systemd service configuration
4. Restart the service if it was running
## Security
NUPST was designed with security in mind:
### Minimal Dependencies
- **Zero Runtime NPM Dependencies**: NUPST is built without any external NPM packages to minimize the attack surface and avoid supply chain risks.
- **Self-contained Node.js**: NUPST ships with its own Node.js binary, isolated from the system's Node.js installation. This ensures:
- No dependency on system Node.js versions
- Zero external libraries that could become compromised
- Consistent, tested environment for execution
- Reduced risk of dependency-based attacks
### Implementation Security
- **Privilege Separation**: Only specific commands that require elevated permissions (`enable`, `disable`, `update`) check for root access; all other functionality runs with minimal privileges.
- **Limited Network Access**: NUPST only communicates with the UPS device over SNMP and contacts npmjs.org only to check for updates.
- **Secure SNMPv3 Support**: Supports encrypted authentication and privacy for secure communication with the UPS device.
- **Isolated Execution**: The application runs in its working directory (`/opt/nupst`) or specified installation location, minimizing the impact on the rest of the system.
### Installation Security
- The installation script can be reviewed before execution (`curl -sSL [url] | less`)
- All setup scripts download only verified versions and check integrity
- Installation is transparent and places files in standard locations (`/opt/nupst`, `/usr/local/bin`, `/etc/systemd/system`)
### Audit and Review
The codebase is small, focused, and designed to be easily auditable. All code is open source and available for review.