Can apps start dbus activated apps inside the same flatpak container?

[Bastien Nocera]

On Tue, 2021-10-19 at 23:20 +0200, Albert Astals Cid wrote:
> When finding a "unsafe SSL certificate" applications using the KDE
> Frameworks libraries ask the org.kde.kssld5 dbus service what to do
> with it since the user may have encountered that certificate first and
> already said "yes i don't care" or "take me away from here fast".
> 
> Now the problem we have in flatpak is that we can't assume that
> "outside" system will know about org.kde.kssld5 because the user may be
> running a system that knows nothing about it.
> 
> We actually do package the binary and dbus autostart files in the KDE
> flatpak runtime so if the runtime could start that service, it would
> all work out.
> 
> But we have no idea if flatpak can be configured to do that.
> 
> Is there any way to say "sure autostart this dbus service inside the
> container, it's fine" in the flatpak world?

Yes you can, but the service's prefix needs to match the name of the
application. This is, for example, how totem and rhythmbox have their
own dleyna UPnP/DLNA D-Bus services:
https://github.com/phako/dleyna-server/commit/fe3caa88097def0eab675aff8a437ad10a0bab7f
https://github.com/flathub/org.gnome.Totem/blob/master/dleyna/dleyna-server.json