[sugar] Initial Security Patches

[Marco Pesenti Gritti]

> > 2
> >
> > * Plug in the security service, enabled conditionally if the Bitfrost
> > service exist.
>
> Agreed, but since this is conditional, I think we should do this as soon
> as I manage to produce acceptable patches.
>

Yeah that make sense.

> > 3
> >
> > * Do some testing and when stuff works well enough enable the Bitfrost
> > service by default on the images.
> >
> > Since one-instance-per-process is a Trial-3 goal, I don't see a lot of
> > value in trying out Bitfrost + multiple instance factory before. We
> > would risk to end up debugging something quite different from the
> > final thing.
>
> Fair enough, but the changes in Rainbow required to drop support for the
> current factory system are minimal; we basically just drop the lines
> that send the `create' message on the session bus, instead passing the
> instance dict on the command line. (Hence we need to agree on an
> argument passing convention.)

But how do you start the service? I presume not by using DBus
activation... My main concern is to not spend time to debug the races
that this might introduce.

If you prefer to start with Bitfrost + multiple-instance-per-process
it's fine with me. Anyway I think we need to do 1 as soon as possible
because that will require the most invasive changes in sugar and in
the activities, and we need some time to get those tested properly
before Trial-3.

Looking forward for updated patches and to start landing this...
Marco