Deployment image customization

[Mitch Bradley]

Michael Stone wrote:
> 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
>
>
>   

See the following for a similar facility that Sun has used for longer 
than I can remember:

http://docs.sun.com/app/docs/doc/802-1930-1M/6i5u98eaf?a=view