KasmVNC Setup on Ubuntu 25.04 – Issues and Incomplete Behavior #338

❗️Summary

I attempted to use KasmVNC to remotely control an existing GNOME session (:0) via browser. Here are the problems I encountered and why the installation experience was frustrating and incomplete on Ubuntu 25.04:

1. Main binary KasmVNCServer not built

The expected binary KasmVNCServer (used to mirror live desktop sessions) is not produced during the default cmake && make build process. Even if the process ends correctly.

Only the kasmvncserver binary (which uses Xvnc and creates a new virtual session) is installed when I used .deb package.

No build-time errors clearly indicate that KasmVNCServer is skipped or what dependencies might be missing for it.

📌 Request: Improve CMake output to show if KasmVNCServer is skipped and why (e.g. missing dependencies or platform support).

2. No official .deb APT repo, so no auto-updates

The .deb installation works but does not add an APT source, so the software doesn’t auto-update.

There is no mention in the docs of how to subscribe to updates or receive security patches.

📌 Request: Provide an optional APT repo or Snap/Flatpak distribution for managed updates.

3. --display :0 does not work in kasmvncserver

Trying to run kasmvncserver --display :0 results in errors, because this command uses Xvnc, which cannot attach to an existing session.

The docs do not clearly explain that only KasmVNCServer supports controlling the live session.

📌 Request: Improve documentation to clearly differentiate between kasmvncserver (Xvnc) and KasmVNCServer (mirror existing session), and explain when/how each should be used.

4. ssl-cert setup is confusing and fragile

The server requires access to /etc/ssl/private/ssl-cert-snakeoil.key, but:

This key was missing on Ubuntu 25.04.

The make-ssl-cert tool didn’t regenerate it properly.

Even after adding the user to ssl-cert, the newgrp method drops into bash and doesn’t return to fish.

📌 Requests:

Detect and regenerate the cert automatically on install.

Improve permission detection or allow alternate SSL configuration (like supplying your own cert path).

5. No auto-start option documented

There’s no documentation on how to run KasmVNCServer automatically at boot with correct environment and permissions.

📌 Request: Provide a systemd service template for headless or semi-headless use cases (e.g. remote admin).

6. Installation feedback is unclear

No clear indication that the server is "ready" after install.

No test command in documentation to confirm if the build worked or which binaries were built.

📌 Request: Add post-install checklist or output that tells users what to expect (e.g., "To mirror session :0, run KasmVNCServer").

🙏 Environment

Ubuntu 25.04 (Plucky Puffin), Intel, GNOME 46

Fish shell

Built from latest KasmVNC GitHub master as of Sept 21, 2025