Sentinel

A GTK4 desktop application for managing systemd services on Linux start, stop, enable, disable, and pin your most used services, all from a clean GUI without running as root.

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Preview

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Features

• Auto-detects — all installed systemd services (enabled + disabled)
• Start / Stop — services with live state (green = running, gray = stopped)
• Enable / Disable — autostart on boot (red = enabled, gray = disabled)
• Pin frequently used services — persisted across reboots (~/.config/sentinel/pinned.txt)
• Pinned tab — dedicated view for your starred services
• Pinned services float to the top — within Enabled/Disabled tabs
• Real-time search — filter by service name
• Refresh — button to re-query all service states
• Privilege escalation — via pkexec (polkit) — no need to launch as root
• Status bar — showing total / enabled / running counts and last refresh time

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Requirements

Dependency	Package (Ubuntu/Debian)
GTK4 dev headers	libgtk-4-dev
CMake ≥ 3.16	cmake
pkg-config	pkg-config
polkit	policykit-1
systemd	(pre-installed on most distros)

Install on Ubuntu/Debian:

sudo apt install libgtk-4-dev cmake pkg-config

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Build

git clone https://github.com/prawesh-12/sentinel.git
cd sentinel

mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
make -j$(nproc)

The binary is at build/sentinel.

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Install (system-wide)

cd build
sudo cmake --install .

This installs:

• Binary — /usr/local/bin/sentinel
• Desktop entry — /usr/local/share/applications/sentinel.desktop
• Icon — /usr/local/share/icons/hicolor/256x256/apps/sentinel.png

After install, Sentinel appears in your application launcher (GNOME, KDE, XFCE).

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Uninstall

sudo rm /usr/local/bin/sentinel
sudo rm /usr/local/share/applications/sentinel.desktop
sudo rm /usr/local/share/icons/hicolor/256x256/apps/sentinel.png

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Project Structure

Sentinel-process-controller/
├── src/
│   ├── main.cpp             # GtkApplication entry point
│   ├── ServiceManager.h/cpp  # systemctl parsing + pkexec execution
│   ├── ServiceRow.h/cpp      # per-service row widget (pin, start, enable)
│   ├── MainWindow.h/cpp      # window layout, sidebar tabs, CSS theme
│   ├── style.css             # GTK stylesheet — edit this to change the theme
│   └── style_css.h.in        # CMake template that embeds style.css at build time
├── CMakeLists.txt
├── sentinel.desktop
├── sentinel.png
└── .gitignore

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How It Works

• Service list is fetched with two batch systemctl calls (fast, no per-service popen loop):
  1. systemctl list-unit-files — enable state
  2. systemctl list-units --all — active state
• Privileged commands (start, stop, enable, disable) run via pkexec systemctl … which triggers a polkit password prompt
• Pinned services are saved to ~/.config/sentinel/pinned.txt and loaded on startup

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Tech Stack

• Language: C++17
• GUI: GTK4 (raw C API)
• Build: CMake
• Service management: systemctl via popen() + pkexec

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License

MIT — see LICENSE.