Synchronizing xs-0.3 and xo-??? --- backups

[Eben Eliason]

On Mon, Apr 28, 2008 at 7:23 PM, Martin Langhoff
<martin.langhoff at gmail.com> wrote:
> On Tue, Apr 29, 2008 at 5:14 AM, Eben Eliason <eben.eliason at gmail.com> wrote:
>  > On Mon, Apr 28, 2008 at 12:58 PM, Michael Stone <michael at laptop.org> wrote:
>  >  > On Mon, Apr 28, 2008 at 10:33:13AM -0400, Eben Eliason wrote:
>  >  >  > Well, I guess I need to know a bit more about the technical details
>  >  >  > that will be in play in this circumstance.  Since we don't have unique
>  >  >  > usernames or passwords, the only identifier for the individual and her
>  >  >  > data is her key, right?  How does one obtain her key if, for instance,
>  >  >  >  her previous machine was bricked or stolen?  And even if she has it,
>  >  >  > must we really require her to type it in?  I suspect we may,
>  >  >  > unfortunately.
>  >  >
>  >  >  Laptops are uniquely identified by their serial-number/uuid pairs. The
>  >  >  ssh keys are incidental. Ivan's proposal (correctly, in my opinion)
>  >  >  calls for backups to be associated with laptops on the XS with an
>  >  >
>  >  >               SN <-> child
>  >
>  >  OK.
>  >
>  >
>  >  >  relation. I regard the problem of associating a new laptop with an
>  >  >  existing child as a problem that can be most conveniently solved with a
>  >  >  configuration tool or UI on the XS.
>
>  Yes - this is the track I am working on.
>
>
>  >  So, backing up one step...this means that in any case where the
>  >  restore needs to be performed on the same laptop, we can do the
>  >  retrieval automatically by silently passing the SN from the XO to XS.
>  >  Correct?  It's only in the new-machine case that we need any user
>  >  intervention, apart from initiation and perhaps confirmation.
>
>  Well, we need to define a workflow that contemplates trust and real
>  life problems. My fuzzy idea was to
>
>   - Get the teacher to indicate via a web-based UI on the XS (to be
>  done later) that new laptop UUID/SN should be associated to this
>  (already existing) user+laptop account.
>   - When the laptop registers, accept the locally generated SSH key and
>  somehow alias both accts together or provide access to the old acct

I was actually referring to a case where the child wanted to do a
restore on their current laptop, rather than a new one, in which case
no new association is needed and it seems there wouldn't be any
XS-side requirements.  Perhaps this is an infrequent use case, in
practice?

>
>  >  As a final option, we could of course check on the XS for a backup
>  >  associated with the machine's SN, and secondarily offer a UI for
>  >  entering the SN association if one doesn't exist.  This has the
>  >  benefit of handling both of the above cases silently as described...as
>
>  I was thinking along the same lines (check for a "related" backup
>  regularly), but based on an association made on the XS by the teacher.

I don't know that it needs to be regularly.  Do you think we should
try to automatically discover when a new "restoration association" is
available?  It seems just as easy to me to require a simple manual
interaction in the XO UI to initiate the check.  Perhaps you could do
a check initially upon boot/login, so that in the case where a kid
boots up a brand new machine for the first time, and the association
has been made in advance, it runs automatically...

>  Tricky aspects remain of defining "teacher" and providing a suitable
>  UI on the XS side, but I will cross that bridge when I get there :-)

It seems that "teacher" basically translates to "the individual with
access to the XS UI", which seems fine to me.

- Eben