Linux Remote Desktop Access

Linux vpn.cs client setup - VPN required for remote access

• See https://vpn.cs.uwaterloo.ca for details
  • Download the vpn.cs ovpn file
  • Click on network icon on toolbar
    • Click on VPN -> Connect -> Enter your CS-GENERAL password.

Setting up an Ubuntu 18.04LTS Desktop for remote access

• You do not want to do this on a server
  • They do not run a GUI.
  • The added packages brought in might mess things up - especially network manager

Linux Ubuntu 18.04LTS Desktop setop for remote access

Desktop software install

• Install Open VPN client
  • apt-get install gadmin-openvpn-client network-manager-openvpn network-manager-openvpn-gnome
• Install Tiger VNC server and client
  • apt install tigervnc-standalone-server tigervnc-xorg-extension tigervnc-viewer
• Install the GUI session manager you will use - I am using Gnome in my examples
  • apt-get install xserver-xorg-core ubuntu-gnome-desktop
• Desktop related functions
  • apt-get install xdg-desktop-portal xdg-desktop-portal-gtk xdg-user-dirs xdg-user-dirs-gtk xdg-utils
• Install and RDP server Windows remote desktop and Linux rdesktop clients can access the Desktop
  • apt-get install xrdp
• Optionally install VPN and RDP client software so you can access other machines
  • apt-get install tigervnc-viewer rdesktop

Desktop Tiger VNC server configuration

• *Setup a VNC password and make it complex (you can use login password)
  • This restricts who has access to your desktop
  • vncpasswd
    • Enter your login password twice, say NO to a view

Desktop VNC server manual startup script

• Note on my system I start the server manually
• Create a startup script called start_vnc
  • chmod 755 start_vnc
  • Update the display geometry below to suit your client display

             #/bin/bash
                            # Kill any existing VNC servers
                            echo We need to stop any VNC servers using sudo - you will be prompted for your password to proceed
                            sudo vncserver -kill :*
                            sudo killall Xtigervnc
                            # Remove any previous stale/dead Xauth files
             xauth remove $HOSTNAME:1
             xauth remove $HOSTNAME:2
             xauth remove $HOSTNAME:3
             xauth remove $HOSTNAME:4
                            # Start vncserver
                            vncserver :1 -localhost -geometry 1800x1000 -depth 24
          

Desktop VNC server client session startup script

• This step is only done once
• make sure you have already run vncpasswd from the previous steps
• The script below will launch your chosen session manager when a client connection is made
  • In my example I use Gnome - I have included other options commented out
• cd ~/.vnc
• sudo bash
• gedit Xvnc-startup

           # Start Gnome 3 Desktop 
           # [ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
           # Or
           # [ -x /etc/X11/Xvnc-session ] && exec /etc/X11/Xvnc-session 
           # [ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
           # Or
           /usr/bin/vncconfig -iconic &
           /usr/bin/dbus-launch --exit-with-session /usr/bin/gnome-session &
        

• chmod 755 xstartup
• ln -s xstartup Xvnc-startup

XRDP setup for Linux rdeskop and Windows remote desktop access

• This step is only done once
• Update xrdp.ini adding restrictions on where XRDP will forward requests to
• I simplified mine so I will be presented with only one choice with defaults sets
• We will comment out all [] sections in the later half or the file
  • Create of modify the section [vnc] as follows
  • sodo bash
  • gedit /etc/xrdp/xrdp.ini

             [vnc]
             name=Xvnc
             lib=libvnc.so
             username=na
             password=ask
             ip=127.0.0.1
             port=ask5901
             #xserverbpp=24
             #delay_ms=2000
          

  • Restart xrdp
    • systemctl restart xrdp

Client connection process

• Make sure your desktop VNC server is running
  • Open a terminal
  • ssh -X userid@host.cs.uwterloo.ca
    • Change userid to yours and host to your desktop
    • Check the xtightvnc server status
      • vncserver -list
    • If you see no sessions listed then start the server
      • ~/start_vnc
• Important on very first access
  • if you have a session manager already running (ie Gnome) on your desktop you need to kill it
    • Otherwise you will get a connection failure from your clients

Connecting to the Desktop remotely from Linux clients

• Make sure you have rdesktop installed
  • Example: From a terminal sudo apt-get install rdesktop
• Starting session
  • open a terminal window and type:
  • rdesktop -r sound:local:alsa -g1850x1000 host.cs.uwaterloo.ca -u userid
    • • replace host and userid *with your remote host name and *userid
    • The session will ask for your VNC password you set earlier
      • It will ask you Three times!

Connecting to the Desktop remotely from Windows clients

• In the search bar type remote desktop
  • Click on the highlighed Remote Desktop app
    • Enter the fully qualified hostname like host.cs.uwaterloo.ca
      • replace host *with your remote host name
    • The session will ask for your VNC password you set earlier
      • It will ask you Three times

Using vnc or rdp with ssh

• ssh -X -L 5999:scspcxxx.cs.uwaterloo.ca:5900 -L 3390:scspcxxx.cs.uwaterloo.ca:3389 root@scspcxxx.cs.uwaterloo.ca

• rdesktop localhost::5999

• xvncviewer localhost:5999

• xvnc4viewer localhost::5999 -ZlibLevel 9 -UseLocalCursor