[openstack-dev] [nova] Using image metadata to sanity check supplied authentication data at nova 'create' or 'recreate' time?

Gregory Haynes greg at greghaynes.net
Mon Jun 6 22:44:19 UTC 2016

On Mon, Jun 6, 2016, at 05:31 PM, Michael Still wrote:
> On Tue, Jun 7, 2016 at 7:41 AM, Clif Houck <me at clifhouck.com> wrote:
>> Hello all,
>>  At Rackspace we're running into an interesting problem: Consider
>>  a user
>>  who boots an instance in Nova with an image which only supports SSH
>>  public-key authentication, but the user doesn't provide a public
>>  key in
>>  the boot request. As far as I understand it, today Nova will happily
>>  boot that image and it may take the user some time to realize their
>>  mistake when they can't login to the instance.
> What about images where the authentication information is inside the
> image? For example, there's just a standard account baked in that
> everyone knows about? In that case Nova doesn't need to inject
> anything into the instance, and therefore the metadata doesn't need to
> supply anything.
We have an element in diskimage-builder[1] which allows a user to pass a
kernel boot param to inject an ssh key if needed due to a reason like
this. Obviously, this wouldn't 'just work' in any normal cloud deploy
since the kernel boot params are baked in to the image itself (this is
currently useful to ironic users who boot ramdisks) but maybe the
pattern is helpful: Check something once at boot time via init script
and that's it. The downside being that a user has to reboot the image to
inject the key, but IMO its a huge decrease in complexity (over
something like file injection) for something a user who just booted a
new image should be OK with.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20160606/41805af4/attachment.html>

More information about the OpenStack-dev mailing list