Linux – does Chrome Remote Desktop support Curtain Mode

chromelinuxremote desktop

I use Chrome Remote Desktop to access my work machine which runs Linux Mint. It's frustrating that, instead of connecting to my existing desktop session (so I can pick up where I left off), it starts a new session upon connecting.

I found that I can modify /opt/google/chrome-remote-desktop/chrome-remote-desktop to force a connection to my existing session like so:

#Change FIRST_X_DISPLAY_NUMBER to this:
FIRST_X_DISPLAY_NUMBER = 0

#Comment out the following lines:
#while os.path.exists(X_LOCK_FILE_TEMPLATE % display);
#display += 1

#Modify the launch_session() method so it's as follows:
def launch_session(self, x_args):
self._init_child_env()
self._setup_pulseaudio()
self._setup_gnubby()
#self._launch_x_server(x_args)
#self._launch_x_session()
display = self.get_unused_display_number()
self.child_env["DISPLAY"] = ":%d" % display

This works, but with a major caveat which has prevented me from actually using it: my monitors at the office stay on and the machine is unlocked for anyone to access.

The page Control use of Chrome Remote Desktop refers to a "Curtain Mode" which is exactly what I want:

To enable Chrome Remote Desktop to prevent someone physically present at a host machine from seeing what a user is doing while a remote connection is in progress

However the provided instructions for enabling it are only for Windows and Mac with no mention of Linux.

Is it possible to enable curtain mode for Linux hosts?

Best Answer

To have the CRD on its own virtual screen for each user, follow the steps here: https://overbrace.com/bernardparent/viewtopic.php?f=91&t=1491

This is similar to curtain mode. When you reconnect, you'll see the same screen you had when disconnecting.

Related Solutions

Remote Desktop – Use KDE Over SSH Reverse Tunnel

If you are using a server-in-the-middle to interconnect two systems, chances are at least one of the lines is rather slow. In that case VNC is likely to give you better performance, since you can tune the bandwidth/performance requiremens/quality ratios better (this is actually valid for most setups, unless you are on a reliable 100Mbit+ network).

I personally like x11vnc, which connects to a running X server and forwards the inputs/output over the VNC protocol (this can be done as soon the X server is running, so you can interact even with a display manager). The X server in question can be both a regular one (which outputs to a real display) or a framebuffer based one like Xvfb. You can then use any VNC client to connect to the exported X server. And of course you probably want to tunnel the transmissionn through ssh or stunnel. The man page of x11vnc is quite exhaustive and even has a frequently used command line example at the beginning.

Ths also allows you to remotely connect to a running session to help somebody solve a problem remotely. As an important bonus, since just the inputs and output are forwarded rather than the X protocol itself, network disconnects will just interrupt the session, but all of the programs remain running, which is not the case of X through SSH.

If for some reason you really want to tunnel X11 through SSH, you must ensure that the DISPLAY environment variable is set up properly by ssh. Without it you can't proceed, because the applications won't know which server to connect to. Check whether the X11Forwarding directive is set to yes in your sshd configuration.

Last but not the least, you probably don't want to run startkde4 (or any other X session for that matter) over SSH - the network load will likely be quite heavy - VNC will serve you better again.

How to achieve the effect of MS remote desktop on Linux

To take control of a running X session you will need to configure your VNC server to connect to the same display as X. Generally, X will be connected to the first display - :0.

You will also need the X Authority for that X session. This can be found by accessing the X Authority file that the remote Display Manager is using. This depends on your Display Manager and can be found using ps aux and grep. For example: psaux | grep Xorg gives you something similar to:

/usr/libexec/Xorg -background none :0 -seat seat0 -auth /var/run/lightdm/root/:0 -listen tcp vt1 -noswitch

Note the -auth option as you'll need it with VNC. You then need to run something like the following as root on the remote computer after installing x11vnc:

/usr/bin/x11vnc -norc -forever -shared -bg -autoport 5900 -auth /var/run/lightdm/root/:0

The easiest way would be to create a service that runs this for you on boot. On distros that use systemd, create a file /etc/systemd/system/x11vnc.service similar to the following:

[Unit]
Description=VNC Server for X11
Requires=display-manager.service
After=display-manager.service

[Service]
Type=forking
ExecStart=/usr/bin/x11vnc -norc -forever -shared -bg \
        -autoport 5900 \
        -rfbauth /etc/x11vnc.pass \
        -o /var/log/x11vnc.log \
        -auth /var/run/lightdm/root/:0

[Install]
WantedBy=graphical.target

Note the -rfbauth option. You'll need to create the password file beforehand using:

$ sudo x11vnc -storepasswd /etc/x11vnc.pass

Alternatively, if you don't feel you need password protected VNC sessions, then simply remove the -rfbauth line.

Enable at boot with:

$ sudo systemctl enable x11vnc.service

Start it manually with:

$ sudo systemctl start x11vnc.service

You can now connect to the remote computer with your VNC client and take over the session.

Best Answer

Related Solutions

Remote Desktop – Use KDE Over SSH Reverse Tunnel

How to achieve the effect of MS remote desktop on Linux

Related Question