Open Stack

On 4/8/19 2:32 PM, Jeremy Stanley wrote:
> On 2019-04-08 03:39:51 +0000 (+0000), Mark Voelker wrote:
>> I don’t think I have a perfect answer here, but just to add fodder
>> to the discussion: it’s often been suggested in the past that one
>> way of dealing with this is to simply ensure that you can bring
>> your image to any cloud you work with.  Thus, rather than relying
>> on an image to be named the same across the clouds you deal with,
>> you can simply provide it yourself on those clouds so you know
>> it’s identical.  Many of the caveats to this approach should be
>> fairly obvious (footprint, duplication, quotas, format conversion,
>> etc), but for some workflows it provides the sorts of useful
>> guarantees an end user may want.
> [...]
> 
> The other problem this works around is that, even if providers offer
> similar images under the same names or via the same image property
> metadata, there's no guarantee that what's on the images is
> identical (same versions of the same set of packages preinstalled
> with the same initial configurations, same root filesystem
> formatting and parameters, et cetera). I too just upload identical
> images to different providers, even for my personal use, so that I
> have some increased assurance of parity for the instances I boot
> there.
> 

The nice thing, is that Glance provides checksums. Meaning that, if you do:

openstack image show -c checksum -f value \
	debian-9.8.2-20190303-openstack-amd64.qcow2

then you can make sure that's the same MD5 than at:

http://cdimage.debian.org/cdimage/openstack/archive/9.8.2-20190303/MD5SUMS

In such case, you know your cloud provider hasn't modified the official
Debian image.

It's just a shame that Glance doesn't show MD5 and not sha512 sums by
default...

Cheers,

Thomas Goirand (zigo)