Custom OS Template (Linux)

While DaDesktop carries a range of popular Linux distros, there may be times when a specific distro that isn’t available is needed. DaDesktop is happy to support this for most mainline Linux distros across New Zealand. Just let us know where to grab the ISO file and which server you’d like to publish the Custom OS template to.

Important:

About Disk Partitioning
1. Customised templates require only one disk partition or two partitions: one EFI/Boot partition and the other system and data partition.
2. An LVM partition is not supported, please don’t use LVM
3. The wrong partition scheme will cause disk auto resize and other functions to fail.

Linux Template

After we’ve downloaded the ISO file to the server, you’ll see it under Admin Menu->OS IMAGES->ISO FILES in your account.

Then you can prepare the template under Admin Menu->OS IMAGES->CUSTOM OS TEMPLATES

Please follow this guide carefully, and complete all the steps as otherwise full DaDesktop operation is likely not to work.

Install OS
Set default username to "student"; Password to "student"
Set "student" account to be Auto Login
Use DaDesktop or your own brand wallpaper
Some distros now default to using Wayland as the display driver. While Wayland works in DaDesktop, at this stage we recommend switching back to X11.

To disable Wayland:

edit /etc/gdm/custom.conf e.g
```
# Uncomment the line below to force the login screen to use Xorg
        WaylandEnable=false
        
```
log out and log in again
Install spice-vdagent, using your package manager is usually the best approach. Note: This may already be installed depending on your distro
- After the correct installation, reboot the machine, and you’ll see the two running processes, spice-vdagent and spice-vdagentd
Install qemu-guest-agent, again, using your package manager is usually the best approach
Install X11VNC. Note: For some distros, you may need to add extra repos such as the 'epel' repo for Red Hat-based distros, such as Oracle Linux or Rocky Linux

Configure X11VNC

make sure X11VNC is installed
run command sudo -i to open root shell

run the command below, which allows X11VNC to auto-start on reboot

cat > /etc/xdg/autostart/x11vnc.desktop <<EOF
                [Desktop Entry]
                Type=Application
                Exec=/usr/bin/x11vnc -N -no6 -rfbportv6 -1 -allow 10.0.3.1 -nopw -shared -alwaysshared -forever -repeat -nowireframe -noscr -nocursorshape -skip_lockkeys -cursor_drag -grab_buster -deferupdate 10 -speeds 6000,5000,20 -afteraccept announce-vnc-users.sh -gone announce-vnc-users.sh
                Hidden=false
                X-MATE-Autostart-enabled=true
                X-MATE-AutoRestart=true
                Name[en_US]=X11VNC
                Name=X11VNC
                Comment[en_US]=Share desktop over VNC
                Comment=Share desktop over VNC
                EOF

Create a desktop notification script by running the commands below

cat > /usr/local/bin/announce-vnc-users.sh <<EOF
        notify-send -a x11vnc "VNC users connected: $RFB_CLIENT_COUNT"
        EOF
        chmod +x /usr/local/bin/announce-vnc-users.sh

Reboot
Check the firewall settings, i.e., make sure TCP port 5900 is open, e.g.

ss -pntl
Disable sudo password (recommended)
Verify success

When you connect, if the URL changes to a new one with a token query parameter, you’re good to go. This means X11VNC is working. The text box at the bottom left of the screen, used for copy/paste between your own desktop and the virtual desktop, should now be operational.

Please Note

To add extra optional features such as

DDWebdav to allow Trainer's content folders to be synchronised to each participant machines,
or DDUpload — to easily upload files to a DaDesktop machine;

Please contact DaDesktop Tech Support.