Customised Linux OS Template

While DaDesktop supports several popular Linux distributions, sometimes you may need a specific distro that isn't included. For most mainstream distributions, DaDesktop is pleased to assist. Kindly provide the ISO file download location and the server on which you'd like the Custom OS template published.

Important:

About Disk Partitioning
1. Custom templates need either a single disk partition or two: one EFI/Boot partition and another for the system and data.
2. LVM partitioning is not supported; please avoid using LVM.
3. An incorrect partition layout will prevent disk auto-resize and other features from working correctly.

Linux Template

Once we download the ISO file to the server, you'll find it listed under Admin Menu->OS IMAGES->ISO FILES in your account.

Afterwards, you can set up the template via Admin Menu->OS IMAGES->CUSTOM OS TEMPLATES

It's essential to follow this guide meticulously and complete every step; otherwise, full DaDesktop functionality may not operate correctly.

Install the operating system
Set the default username to "student" and the password to "student"
Configure the "student" account for automatic login
Apply the DaDesktop wallpaper or a custom branded image
Certain distributions now default to Wayland as the display driver. While Wayland works in DaDesktop, we currently 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 then log back in
Install spice-vdagent; using your distribution's package manager is normally the best method. Note: It might already be installed on your system.
- Once installed correctly, reboot the machine and verify that the two processes, spice-vdagent and spice-vdagentd, are running.
Install qemu-guest-agent; again, using the package manager is usually the best approach.
Install X11VNC. Note: For some distributions, you may need to enable additional repositories, like the 'epel' repo for Redhat-based distributions such as Oracle Linux or Rocky Linux.

Configure X11VNC

Ensure X11VNC is installed.
Run sudo -i to open a root shell.

Execute the following command to enable X11VNC to auto-start upon 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

Set up 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 the system.
Verify the firewall settings, ensuring TCP port 5900 is open, for example by running:

ss -pntl
Disable the sudo password requirement (recommended).
Verify success

Upon connecting, if the URL transforms into a new one containing a token query parameter, everything is set. This indicates X11VNC is functional. Additionally, the text box located at the bottom left of the screen—used for copying and pasting between your local and virtual desktops—should operate correctly.

Please Note

To incorporate additional optional features, such as

DDWebdav for synchronizing the trainer's content folders to each participant's machine,
or DDUpload, which facilitates easy file uploads to a DaDesktop machine;

Please reach out to DaDesktop Technical Support.