bug#21843: Generated grub.cfg does not support encrypted roots

[Andreas Enge <andreas@enge.fr>]

On Thu, Mar 10, 2016 at 10:17:46AM +0100, Ludovic Courtès wrote:
> Furthermore, to allow users to specify a LUKS UUID as the ‘source’ of
> their ‘mapped-device’ form, as in:
>    (mapped-device
>      (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44")) ;LUKS UUID
>      (target "root")
>      (type luks-device-mapping))
> we’d have to extend <mapped-device-kind> with a method to resolve UUIDs
> (in this case, to map a UUID to a /dev node.)

I just read a bit of the cryptsetup manual; we do not need to do the
resolution, in the above example we would have the line
   cryptomount -u cb67fc72-0d54-4c88-9d4b-b225f30b0f44
(as discussed previously; it works at least without the dashes, we can also
try to keep the dashes).
And then it should be possible to open the device with
   cryptsetup luksOpen UUID=cb67fc72-0d54-4c88-9d4b-b225f30b0f44 root
This looks for the given uuid in /dev/disk/by-uuid.

I wanted to give it a try with the installation image, but unfortunately it
does not contain the directory /dev/disk.

Andreas