Repo has xpra packages for 17.04, but not winswitch.

When the client connects to the server, there are port forwarding and application startup errors.

[II] 2018/13/04 09:38:53.375532 ConchConnection.forward_port(12497,127.0.0.1,24065)
[II] 2018/13/04 09:39:31.742001 WinSwitchApplet.do_start_session(ServerConfig(desktop:158515233878749),Command(Mousepad: mousepad %F),xpra,None,{},False)
[II] 2018/13/04 09:39:31.742075 WinSwitchApplet.attention(Starting Mousepad,None)
[II] 2018/13/04 09:39:31.742134 StatusIconTray.animate_status_icon(Starting Mousepad,5) now=1523601571.74, tray_widget_animate_until=1523601505.56
[II] 2018/13/04 09:39:31.908503 ServerLink.add_port_forward(None,127.0.0.1,15071) adding new port forward
[II] 2018/13/04 09:39:31.908637 ConchConnection.forward_port(12498,127.0.0.1,15071)
[II] 2018/13/04 09:39:35.937471 ServerLineConnection.do_message(9e007000aad84b759b6f03735717ba4d,Session Mousepad Failed,Session failed to start,)
[II] 2018/13/04 09:39:54.238773 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(Gscriptor: gscriptor)) missing icon!
[II] 2018/13/04 09:39:54.239043 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(Jaxx: "/home/username/cryptowallets/jaxx-1.3.13-x86_64.AppImage" %U)) missing icon!
[II] 2018/13/04 09:39:54.240210 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(TurboVNC Viewer: /opt/TurboVNC/bin/vncviewer)) missing icon!
[II] 2018/13/04 09:39:54.241673 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(OpenCity: opencity)) missing icon!
[II] 2018/13/04 09:39:54.247141 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(aMule: amule %u)) missing icon!
[II] 2018/13/04 09:39:54.251555 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(Power Manager: xfce4-power-manager-settings)) missing icon!
[II] 2018/13/04 09:39:54.252573 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(TeXdoctk: texdoctk)) missing icon!
[II] 2018/13/04 09:39:54.253640 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(PyCrust: pycrust)) missing icon!
[II] 2018/13/04 09:39:54.255005 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(LMMS: env QT_X11_NO_NATIVE_MENUBAR=1 lmms %f)) missing icon!
[II] 2018/13/04 09:39:54.257128 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(GAdmin-Rsync: su-to-root -X -c /usr/sbin/gadmin-rsync)) missing icon!
[II] 2018/13/04 09:39:54.257361 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(GSmartControl: "/usr/bin/gsmartcontrol-root")) missing icon!
[II] 2018/13/04 09:39:54.259273 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(UNetbootin: /usr/bin/unetbootin)) missing icon!
[II] 2018/13/04 09:39:54.287996 WinSwitchApplet.do_start_session(ServerConfig(desktop:158515233878749),Desktop(Xfce Session: startxfce4),vnc,None,{},False)
[II] 2018/13/04 09:39:54.288073 WinSwitchApplet.attention(Starting Xfce Session,None)
[II] 2018/13/04 09:39:54.288128 StatusIconTray.animate_status_icon(Starting Xfce Session,5) now=1523601594.29, tray_widget_animate_until=1523601576.74
[II] 2018/13/04 09:39:54.547923 ServerLink.add_port_forward(None,127.0.0.1,16072) adding new port forward
[II] 2018/13/04 09:39:54.548147 ConchConnection.forward_port(12499,127.0.0.1,16072)
[II] 2018/13/04 09:39:55.599431 ProtocolHandler.do_encrypted_command(78296cadaa664db4903f9daf30f421f5e745774aa2ab268880acc074aa64e8b4be461c80a2b4e9d6cb5be604d2dc6d8d7...) decrypted command=send_session '4011ea7ccbbf4b4caa82f47d86bb0b98','9e007000aad84b759b6f03735717ba4d','base64:N2UyNGMwMmE= '
[II] 2018/13/04 09:39:55.599610 VNCClientUtil.attach(ServerConfig(desktop:158515233878749),ClientSession(:71 - vnc - connecting),127.0.0.1,12499)
[II] 2018/13/04 09:39:55.625427 VNCClientUtil.do_real_attach(ServerConfig(desktop:158515233878749),ClientSession(:71 - vnc - connecting),127.0.0.1,12499) saved password '#######' in /home/username/.winswitch/client/sessions/4011ea7ccbbf4b4caa82f47d86bb0b98/session.pass
[II] 2018/13/04 09:39:55.625532 VNCClientUtil.exec_client(ServerConfig(desktop:158515233878749),ClientSession(:71 - vnc - connecting),['/usr/bin/vncviewer', 'PasswordFile=/home/username/.winswitch/client/sessions/4011ea7ccbbf4b4caa82f47d86bb0b98/session.pass', 'name=Xfce Session on desktop', '127.0.0.1::12499'],None,None,available,True) starting SimpleLineProcess
[II] 2018/13/04 09:39:55.634440 VNCClientUtil.started(<winswitch.util.process_util.SimpleLineProcess instance at 0x7f5abbdf4dd0>) pid=None
[II] 2018/13/04 09:39:55.634966 SimpleLineProcess.start() process(['/usr/bin/vncviewer', 'PasswordFile=/home/username/.winswitch/client/sessions/4011ea7ccbbf4b4caa82f47d86bb0b98/session.pass', 'name=Xfce Session on desktop', '127.0.0.1::12499'])=<Process pid=6419 status=-1>
[II] 2018/13/04 09:39:56.214816 PortForwardChannel.__init__(<winswitch.net.conch_util.ConchConnection instance at 0x7f5ac06b5b48>,<function forwarding_ready at 0x7f5abbdd7578>,<function forwarding_failed at 0x7f5abbdd7aa0>)
[II] 2018/13/04 09:39:56.214968 ConchConnection.openChannel(<winswitch.net.conch_util.PortForwardChannel instance at 0x7f5abbdf4758>,'\x00\x00\x00\t127.0.0.1\x00\x00>\xc8\x00\x00\x00\t127.0.0.1\x00\x00\xcf\xde')
[II] 2018/13/04 09:39:56.215638 VNCClientUtil.handle_line_connected(ClientSession(:71 - vnc - connecting), CConn:       connected to host 127.0.0.1 port 12499) ServerConfig(desktop:158515233878749)
[II] 2018/13/04 09:39:56.215699 WinSwitchApplet.update_session_status(ServerConfig(desktop:158515233878749),ClientSession(:71 - vnc - connecting),connected)
[II] 2018/13/04 09:39:56.243185 ServerLink.forwarding_ready()

Important:

• it needs a man page - this is a debian requirement: all public commands (ie: /usr/bin/) need a man page, even if it is a small one that refers to another one

More minor issues:

• how do you create your config files? this needs to be documented somewhere, maybe providing an example config with comments in /usr/share/winswitch/launcher-example/
• I've removed the default values from LauncherSession to ensure they are populated correctly from file - the code should ensure the values make sense (port>0, host.len>0)
• LauncherClient should show a warning if the session fails to start
• file mime-type mapping so users can double click on them and have the software automatically launched
• dealing with ssh-tunnels (totally non-trivial)