Xpra
Xpra is 'GNU Screen for X': it allows you to run X programs, usually on a remote host, direct their display to your local machine, and then to disconnect from these programs and reconnect from the same or another machine, without losing any state. It gives you remote access to individual applications.
- Xpra is "rootless" or "seamless": programs you run under it show up on your desktop as regular programs, managed by your regular window manager.
- Sessions can be accessed over SSH, or password protected over plain TCP sockets.
- Xpra is usable over reasonably slow links and does its best to adapt to changing network bandwidth limits. (see also adaptive JPEG mode)
- Xpra is open-source (GPLv2+), multi-platform and multi-language, with current clients written in Python and Java.
From the Xpra website:
Usage
Run application "single shot"
To run an application remotely over SSH without starting an xpra server on the host it is running on in advance, you can simply use this command on your client machine:
$ xpra start ssh:user@host --exit-with-children --start-child="command"
Where "command" is the command you would start on the remote hosts shell. This will start xpra remotely and shuts down the xpra server when the command exits.
If you see Public Key not accepted by remote side, .ssh/config not used correctly, try to use your normal system ssh client instead of the integrated Paramiko SSH client:
$ xpra start --ssh="ssh" ssh:user@host --exit-with-children --start-child="command"
Run applications in a persistent xpra server on the remote host
If you want to have a persistent server on the remote machine, you can start an xpra server on the machine where you want to run the applications (we are using display number 7 here):
$ xpra start :7
Now you can start an application, e.g. firefox:
$ DISPLAY=:7 firefox
Or, if you want to start a screen session and execute the programs from there to be able to close the console:
$ DISPLAY=:7 screen [screen starts] $ firefox
Note that if you start screen like this you do not have to specify the display number when executing programs. They will be running on the xpra display automatically.
After running these commands, you do not see any windows yet. To actually see the applications on your display, you have to connect to the xpra server. If you are connecting to an xpra display on the same machine, start the xpra client like this:
$ xpra attach :7
Or, if you are connecting to a remote machine over ssh:
$ xpra attach ssh:user@example.com:7
After starting the client, any programs running on the remote server display are displayed on your local screen. To detach, type ctrl-c or use the command:
$ xpra detach ssh:user@example.com:7
Programs continue to run on the server and you can reattach again later.
You can stop the server with:
$ xpra stop :7
on the machine where the server is running, or remotely:
$ xpra stop ssh:user@example.com:7
Run whole desktop environment
To run whole desktop (on the server side):
$ xpra start-desktop :7 --start-child=xfce4-session --exit-with-children
where:
:7is a number of xorg DISPLAY session--start-child=xfce4-sessionrun xfce4 session as child on xpra server--exit-with-childrenmean that server will be closed after session logout (children exit)
To attach it (on the server side):
$ xpra attach :7
To attach it (on the client side):
$ xpra attach ssh:user@example.com:7
To detach press ctrl+c on terminal or run:
$ xpra detach :7
Shadow remote desktop
To clone:
- display must be auth by this same user as ssh login to
- display must be shown on remote screen
To shadow desktop run this on the client side:
$ xpra shadow ssh:DISPLAY_user@example.com:DISPLAY_number
As xorg sandbox
Sandox can be achieved with firejail:
- for application sandbox (change
eth0to your interface name or tonone): - xpra attach, etc:
More
For a complete manual, see .
Tips and tricks
Server
It is possible to start the xpra server at boot using a systemd unit.
Create the unit file:
/etc/systemd/system/xpra@.service
[Unit]
Description=xpra display
[Service]
Type=simple
User=%i
EnvironmentFile=/etc/conf.d/xpra
ExecStart=/usr/bin/xpra --no-daemon start ${%i}
[Install]
WantedBy=multi-user.target
Now create the configuration, adding a line for each username you want to have an xpra display:
/etc/conf.d/xpra
myusername=:7
Enable the service for each username that owns a display. In this example, the service would be .
Method 1: .xinitrc
Add to your file the line necessary to start the connection, adding an & at the end of the line.
Make sure to add such line before the line.
For example, on a remote client it could be:
Method 2: systemd user session
Configure your session to use systemd user session. Read Systemd/User for details.
Create the following service unit:
Create the configuration file, using the options you want:
The service name would be in the format of .
Example: xpra-client@ssh:myuser@example.com:7.service
Troubleshooting
Error: Only console users are allowed to run the X server
If the execution fails with this error message in the log file you need to make the following changes:
Create the following:
/etc/X11/Xwrapper.config
allowed_users=anybody
Error: failed to connect to display :100
Sometimes this errors are produced:
To solve it is necessary run with . Example:
$ xpra start ssh://$USER@$SERVER/100 --start-child=/usr/bin/terminator --xvfb=/usr/bin/Xorg
Problem: Fonts are rendered in wrong sizes or clicks will not register after resizing a window
Try to install the package, if you encounter problems with font rendering or missed clicks after resizing a remote window. It contains the xf86-video-dummy driver with patches from the xpra team, that are meant to help with these problems.
For the patches and further information see: