GitHub - lsferreira42/internet-indicator: A gtk3 internet connectivity indicator

3 min read Original article ↗

A blazing-fast, ultra-lightweight system tray app written in pure C (GTK3 / AppIndicator) that constantly monitors your internet connection.

I built this because I was tired of second-guessing if my ISP was dropping packets or if my VPN was acting up, and I needed hard proof without keeping a terminal open running ping all day. It sits quietly in your tray, tracks your real-time latency, and logs every dropout directly into a searchable UI.

Why this over a bash script?

  • Because I wanted to its a good exercise to learn C and GTK3.
  • Zero bloat. It runs on negligible RAM footprint.
  • Multithreading done right. Network requests run in a detached thread behind a GMutex lock. The UI never freezes, even if DNS resolution hangs.
  • No false positives. Hooks into Linux D-Bus (logind) to automatically pause checks while your system sleeps or is screen-locked.
  • Embedded Assets. Can compile the icons directly into the C binary — single standalone executable.

🚀 Key Features

  • Dual Checking Engines:
    • ICMP Mode: Smart datagram ping (SOCK_DGRAM) with full hostname resolution (getaddrinfo) and strict sequence matching. No root/sudo needed if CAP_NET_RAW is applied!
    • HTTP Mode: Powered by libcurl. Want to ping a captive portal or a localized intranet endpoint? Configure custom headers, methods (GET/HEAD/POST), toggle SSL verification, and specify accepted status codes (e.g., 200,301).
  • Live Latency Tooltips: Hover your tray to instantly see your latency via CLOCK_MONOTONIC metrics (e.g., ✓ Connected — ping.example.com (14ms)).
  • Desktop Notifications: Native libnotify integration. Get an immediate system popup the second your network drops or recovers.
  • Auditable Connection Logs: Built-in log rotation (configure size in KB). The Settings dialog contains a Logs Tab with a fully searchable UI (GtkTreeView) so you can pinpoint exactly when your connection failed to complain to your ISP.
  • Robust Error Diagnostics: Any socket, HTTP, or DNS failures aren't just thrown to stderr, they're piped directly into your UI tray as an error row.

📦 Installation

Distro Packages

We currently support DEB, RPM, and Alpine APK packaging right out of the box via the Makefile.

# Ubuntu, Mint, Debian
make deb

# Fedora, RHEL, openSUSE
make rpm

# Alpine (via reproducible Docker container)
make apk

The generated packages are tossed into the build/ directory.

Building from Source

Just want a portable binary to throw in your ~/bin folder without polluting your package manager?

# Compiles a standalone executable with icons embedded directly as C arrays
make distributable

# Run it directly
./internet-indicator-standalone

System Integration

Install globally to applications menu and systemd background service:

(This automatically adds the .desktop file to your app launcher and sets CAP_NET_RAW permissions).

To ensure the indicator boots up automatically on startup:

🛠️ Development & Tooling

This project ships with heavy Makefile automation tailored for CICD and package maintainers:

  • make docker: Builds an ultra-minimal Alpine container running the indicator (under <35MB).
  • make clean: Clears all build artifacts.
  • make bump-version-[bugfix|minor|major]: Automatically bumps the VERSION file and securely updates the .control, .spec, and Dockerfile packaging metadata.

License

MIT. PRs and forks are extremely welcome.