[winswitch] Upgrading from Xpra 1 to Xpra 3

[Antoine Martin]

On 24/06/2020 20:47, Eric Lemings via shifter-users wrote:
> Hello all,
> 
> I recently upgraded from Xpra 1.0.13 to Xpra 3.0.9.
FYI: 3.0.10 is the current version for CentOS / RHEL 7.

>  I am trying to get
> Xpra 3 to start under a Linux system account (RHEL 7 to be exact) as before
> under Xpra 1.  The exact command looked something like this:
> 
> $ /usr/bin/python2 /usr/bin/xpra start :42 --log-dir=/an-install-dir/.xpra
> --sharing=yes --map-group
There is a typo, and you need to specify the group to use:
--mmap-group=MMAP_GROUP

> --socket-dir=/an-install-dir/.xpra
> -socket-dirs=/an-install-dir/.xpra:/tmp --socket-permissions=660
Typo: "--socket-dirs=..."

> --systemd-run=no 
> --remote-xpra=/an-install-dir/.xpra/run-xpra
FYI: setting "--remote-xpra" does not make sense with the "start"
subcommand as it is only ever used with ssh connections.

> --pulseaudio=no --remote-logging=yes --speaker=disabled --system-tray=no
> --webcam=no --mdns=no --notifications=no
Works fine here with "/run/xpra" on Fedora and CentOS 7
> The usage and options might not have been technically correct but it
> worked... for Xpra 1.  Doesn't work so well for Xpra 3.
Please always include the full error messages, log samples, etc.

> At first, the
> system account did not belong to the 'xpra' group but it would not reliably
> open a socket in the /an-install-dir/.xpra directory.
I don't know what permissions or ownership you have set on this directory.
The standard location for 'xpra' group sockets is '/run/xpra'.
Why not use that?

>  After adding the
> 'xpra' group to the system account, it doesn't seem to ever set group
> read/write permissions or use the system account group -- only the 'xpra'
> group.
It's not clear to me what you were expecting or what actually happened.

Have you checked the obvious: logging back in after adding the 'xpra'
group perhaps?

> First question: Is there a wiki page or other document that outlines the
> procedures for using Xpra 3 under a system account to be shared by multiple
> users?
No, but feel free to create one. The man page is the reference and
should always be up to date.

> Second question: What would be the equivalent Xpra 3.0.9 command for the
> Xpra 1 command shown above?
This simple command works for me and allows other members of the 'xpra'
group to connect to the session:
xpra start :42 --socket-permissions=660 --mmap-group=xpra --sharing=yes

(you can then add your audio, system-tray, etc options - those are not
relevant to this question, the syntax is the same as before)

Cheers,
Antoine

> 
> Much appreciated.
> 
> Eric.