Deployment image customization

[Michael Stone]

On Tue, Dec 23, 2008 at 03:29:08PM -0500, pgf at laptop.org wrote:
>daniel wrote:
> > On Tue, Dec 23, 2008 at 8:08 PM,  <pgf at laptop.org> wrote:
> > > ssh host keys are probably generated on first boot as well.
> > >
> > > with partitioning support, it should be possible to have a r.o. root
> > > overlaid by a unionfs writeable mount, so machine-specific changes
> > > don't modify the released partition.  this would make cloning quite a
> > > bit easier, i'd think.  i have no idea what the performance hit of
> > > a unionfs setup would be, nor how such a partitioning would fit
> > > into the rest of the update strategy (e.g.  olpc-update).
> > 
> > unionfs isn't upstream and was quite unreliable last time I use it.
> > And it adds the challenge of differentiating state that must be
> > discarded for the cloned image, and state that must not be.
> > 
> > For example, we would want to ssh keys generated during first boot to
> > *not* be included in the clonable image, that's obvious. But if the
> > user boots the OLPC image, goes into the control panel and sets a
> > language, then we *do* want that language change to be included in the
> > clonable image that is the output of the process.
> > 
> > How would the system differentiate between those two?
>
>i dunno.  i guess the lead engineer on the project would have to
>decide.  :-)

In my opinion, the simplest way to approach this is to add a
"hard-reset" script (perhaps named "olpc-hard-reset") which cleans up
the image and then prints out a diff from the starting image to the
result for manual review.

Michael