Difference between revisions of "Xpra"

Revision as of 10:25, 4 October 2013

From the Xpra website:

Xpra is '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.

Installation

Install the package xpra-winswitch^AUR from the AUR, in the server and client(s) machines.

Use

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 don't have to specify the display number when executing programs. They will be running on the xpra display automatically.

After running these commands, you don't 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

For a complete manual, check man xpra.

Tips and tricks

Start at boot

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 xpra@myusername.service.

Client

Method 1: .xinitrc

Add to your ~/.xinitrc file the line necessary to start the connection, adding an & at the end of the line.

Make sure to add such line before the exec line.

For example, on a remote client it could be:

~/.xinitrc

xpra attach ssh:user@example.com:7 &

Method 2: systemd user session

Configure your session to use systemd user session. Read Systemd/User for details.

Create the following service unit:

$HOME/.config/systemd/user/xpra-client@.service

[Unit]
Description=xpra client

[Service]
Type=simple
EnvironmentFile=%h/.config/conf/xpra_client
ExecStart=/usr/bin/xpra attach %i $OPTS

[Install]
WantedBy=default.target

Create the configuration file, using the options you want:

$HOME/.config/conf/xpra_client

OPTS=--encoding=jpeg --quality=90

The service name would be in the format of xpra-client@ssh:username@hostname:<display number>.service.

Example:

xpra-client@ssh:myuser@example.com:7.service

Enable that service, and remember to use the --user flag on systemctl.

See also

• Xpra website