[pve-devel] [PATCH storage/qemu-server/pve-manager] implement ova/ovf import for directory type storages

[Fabian Grünbichler]

On April 18, 2024 12:35 pm, Fiona Ebner wrote:
> Am 18.04.24 um 11:27 schrieb Dominik Csapak:
>> ok after a bit of thinking and discussing off-list
>> the plan to go forward from my side is this:
>> 
>> (please tell if there is something obviously wrong with it or you'd
>> strongly prefer something differently)
>> 
>> extract on demand vs on upload:
>>  i'd go with extract on demand because managing the extraction of the
>> tarball + subdir etc is not really a win in my book, since we have to
>> have most safeguards anyway and we have the same
>> issue of where to store/map it etc. also it's not convenient for users
>> that have already
>> a bunch of ovas and want to store them in a central place, now they'd
>> have to extract
>> them just for us (and importing should be as small a hassle as it can be)
>> 
> 
> The upside is that it would avoid all the extra cleanup handling and be
> more efficient for users that want to import from a single OVA multiple
> times. But you are right, the downside is also very big.
> 
> I'm thinking now, is there no way to expose a file in an OVA/tar without
> actually extracting it? I.e. something like
> 
>> root at pve8a1 ~ # cat B         
>> secret
>> root at pve8a1 ~ # tar cf arch.tar A B dir
>> root at pve8a1 ~ # losetup --offset 1536 --sizelimit 512 --read-only --show -f arch.tar
>> /dev/loop0
>> root at pve8a1 ~ # cat /dev/loop0
>> secret
> 
> but that doesn't seem to work with sizelimit < 512. Not claiming losetup
> is a good mechanism for that, just to illustrate the idea.

there are a few projects that basically offer "tar browsing via FUSE" in
some fashion, not sure about their overhead and/or compat with various
tar variants and features though..