[Openstack-operators] [openstack-dev] [glance] [nova] Glance bug with Kilo upgrade & Nova

Bhandaru, Malini K malini.k.bhandaru at intel.com
Tue Jun 9 07:38:06 UTC 2015

A DB migrate script that puts some token default string only for glance properties that are NULL. Should not change anything else.
Hope it works Flavio.

-----Original Message-----
From: Flavio Percoco [mailto:flavio at redhat.com] 
Sent: Tuesday, June 09, 2015 12:33 AM
To: Bhandaru, Malini K
Cc: OpenStack Development Mailing List (not for usage questions); openstack-operators at lists.openstack.org
Subject: Re: [openstack-dev] [glance] [nova] Glance bug with Kilo upgrade & Nova

On 09/06/15 09:22 +0200, Flavio Percoco wrote:
>On 09/06/15 07:09 +0000, Bhandaru, Malini K wrote:
>>Flavio, would a DB script that writes an empty string or NOP or something instead of NULL In the column do the trick?
>>Then the problem degenerates to a new DB upgrade script.
>I now remembered about a change[0] - that I wrote myself - that 
>required a bump on the API version - which we did - that allows None 
>values to be returned in the API. This is probably what is causing this 
>A DB migration would certainly work, I'd love to avoid it but I guess 
>that's the best solution in this case.

Actually, we can't just migrate the database as there might be custom properties that were explicitly set to None.

I'll keep you posted

>[0] https://review.openstack.org/#/c/138184/
>>-----Original Message-----
>>From: Flavio Percoco [mailto:flavio at redhat.com]
>>Sent: Monday, June 08, 2015 11:47 PM
>>To: OpenStack Development Mailing List (not for usage questions)
>>Cc: openstack-operators at lists.openstack.org
>>Subject: Re: [openstack-dev] [glance] [nova] Glance bug with Kilo 
>>upgrade & Nova
>>On 08/06/15 11:46 -0400, Clayton O'Neill wrote:
>>>We tested testing Kilo upgrades in our hardware dev environments last 
>>>week and the second time through ran into this bug which right now is 
>>>probably a show-stopper for us.
>>>The issue here is that the v1 Glance API allows you to create images 
>>>with properties that are 'NULL' in the Glance database.  For example:
>>>    glance image-create --name cirros_test --disk-format qcow2 
>>>--container-format bare --file cirros-0.3.4-x86_64-disk.img 
>>>--is-public True --is-protected True --progress --property 
>>>It's apparently also fairly easy to end up with a NULL description 
>>>when editing images properties via Horizon.
>>>The issue is that the v2 Glance API returns these NULL properties to 
>>>the client, which then validates them against the schema returned by the v2 API.
>>>This schema returns specifies that the description property *must* be a string.
>>>In the Kilo release, Nova has been changed to use the v2 API, so 
>>>suddenly this matters.  The net effect is that end users can pretty 
>>>easily create properties with NULL values, and then won't be able to boot instances using those images.
>>>What makes this worse is that it's completely opaque to end users, 
>>>since this just reports that no node was available to schedule the instance.
>>>However, Nova *only* uses the v2 api to list images if the 
>>>glance.allowed_direct_url_schemes config key is set in the config file.
>>>However, this config item defaults to an empty array, meaning that by 
>>>default it's *always* set.  There doesn't appear to be a way to unset 
>>>a value with oslo-config that has a default value, blocking off that 
>>>route to work around the issue.  Disabling the v2 Glance API we don't 
>>>think will work, since Nova appears to assume the v2 API is available.
>>AFAIK, Nova supports V2 image-lists since before Juno when the allowed_direct_url_schemes config option is set. Are you referring to another change? Has the default been changed in Nova? I'm asking because I was working on this migration to V2 and we decided to postpone it to L.
>>>Another work around we've looked at is to change the DB schema for 
>>>image properties (yuck) to not allow NULL values.  This results in 
>>>Glance returning a
>>>500 error since glance-api is attempting to insert an invalid value. 
>>>This is better than instances failing in an opaque fashion, but still pretty horrible.
>>>Has anyone else run into this issue yet?  Are there other work 
>>>arounds that we've not thought of other than "Don't create images with NULL properties?"
>>>User education is definitely an option, but given the failure mode, 
>>>it's not a great solution for us.
>>I believe this needs to be fixed in the client rather than the API and/or the schemas. I'll take a look at this right away.
>>Another workaround could be updateting `schema-image.json` to add the schemas that are missing and let the client download the final schema from the V2 API.
>>Keep an eye on the bug, patches coming your way (assuming what I have in mind will work).
>>Flavio Percoco
>Flavio Percoco

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Flavio Percoco

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