Custom OS Template (Linux)

Although DaDesktop maintains a number of popular Linux distros, there may be an occasion when a specific distro that is not available is required. DaDesktop are happy to support this for most mainline Linux distros. Please tell us where to download the ISO file and which server you want to publish the Custom OS template.

Important:

About Disk Partitioning
1. Customized 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 do not use LVM
3. The wrong partition scheme will cause disk auto resize and other functions to fail.

Linux Template

After we download the ISO file to the server, you will be able to see it under Admin Menu->OS IMAGES->ISO FILES under 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 will now default to using Wayland as their display driver. Although Wayland works in DaDesktop, for now we suggest to revert 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
        
```
logout and login again
Install spice-vdagent, using your package manager is usually the best approach. NB This may already be installed depending on your distro
- After the correct installation, restart the machine, and you should 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. NB For some distros, you make need to add extra repos such as the 'epel' repo for Redhat based distros, such as Oracle Linux or Rocky Linux

Configure X11VNC

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

run the below command 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 desktop notify script by running below commands

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 firewall setting, ie make sure TCP port 5900 is open, eg

ss -pntl
Disable sudo password ( recommended )
Verify success

When connect, the URL, if changed to a new URL with token query parameter, then you are good to go. This means X11VNC is working. And the text box at the bottom left of the screen, which is used for copy/paste between your own desktop and virtual desktop should now be working.

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 within a DaDesktop machine;

Please contact DaDesktop Tech Support.