Open Stack

-----邮件原件-----
发件人: Flavio Percoco [mailto:flavio at redhat.com] 
发送时间: 2017年1月10日 15:34
收件人: OpenStack Development Mailing List (not for usage questions)
主题: Re: [openstack-dev] [heat] glance v2 support?

On 10/01/17 12:35 +0530, Rabi Mishra wrote:
>On Mon, Jan 9, 2017 at 4:45 PM, Flavio Percoco <flavio at redhat.com> wrote:
>
>> On 06/01/17 09:34 +0530, Rabi Mishra wrote:
>>
>>> On Fri, Jan 6, 2017 at 4:38 AM, Emilien Macchi <emilien at redhat.com>
>>> wrote:
>>>
>>> Greetings Heat folks!
>>>>
>>>> My question is simple:
>>>> When do you plan to support Glance v2?
>>>> https://review.openstack.org/#/c/240450/
>>>>
>>>> The spec looks staled while Glance v1 was deprecated in Newton (and 
>>>> v2 was started in Kilo!).
>>>>
>>>>
>>>> Hi Emilien,
>>>
>>> I think we've not been able to move to v2 due to v1/v2 
>>> incompatibility[1] with respect to the location[2] property. Moving 
>>> to v2 would break all existing templates using that property.
>>>
>>> I've seen several discussions around that without any conclusion.  I 
>>> think we can support a separate v2 image resource and deprecate the 
>>> current one, unless there is a better path available.
>>>
>>
>> Hi Rabi,
>>
>> Could you elaborate on why Heat depends on the location attribute? 
>> I'm not familiar with Heat and knowing this might help me to propose 
>> something (or at least understand the difficulties).
>>
>> I don't think putting this on hold will be of any help. V1 ain't 
>> coming back and the improvements for v2 are still under heavy coding. 
>> I'd probably recommend moving to v2 with a proper deprecation path 
>> rather than sticking to v1.
>>
>>
>Hi Flavio,
>
>As much as we would like to move to v2, I think we still don't have a 
>acceptable solution for the question below. There is an earlier ML 
>thread[1], where it was discussed in detail.
>
>- What's the migration path for images created with v1 that use the 
>location attribute pointing to an external location?

Moving to Glance v2 shouldn't break this. As in, Glance will still be able to pull the images from external locations.

Also, to be precise more precise, you actually *can* use locations in V2.
Glance's node needs to have 2 settings enabled. The first is `show_multple_locations` and the second one is a policy config[0]. It's however not recommended to expose that to end users but that's why it was shielded behind policies.
---As you said, we can't use location in v2 by default. IMO, If glance v2 is compatible with v1, the option should be enabled by default.

I'd recommend Heat to not use locations as that will require deployers to either enable them for everyone or have a dedicate glance-api node for Heat.
----If not use location, do we have other options for user? What should user to do before create a glance image using v2? Download the image data? And then pass the image data to glance api? I really don't think it's good way.

All that being said, switching to v2 won't prevent Glance from reading images from external locations if the image records exist already.
----Yes, but how to create a new glance image?

[0] https://github.com/openstack/glance/blob/master/etc/policy.json#L16-L18

>While answering the above we've to keep in mind the following constraint.
>
>- Any change in the image id(new image) would potentially result in 
>nova servers using them in the template being rebuilt/replaced, and we 
>would like to avoid it.
>
>There was a suggestion to allow the 'copy-from'  with v2, which would 
>possibly make it easier for us. Is that still an option?

May be, in the long future. The improvements for v2 are still under heavy development.

>I assume we can probably use glance upload api to upload the image 
>data(after getting it from the external location) for an existing image?
>Last time i tried to do it, it seems to be not allowed for an 'active'
>image. It's  possible I'm missing something here.  We don't have a way 
>at present,  for a user to upload an image to heat engine( not sure if 
>we would like do to it either) or heat engine downloading the image 
>from an 'external location' and then uploading it to glance while 
>creating/updating an image resource.

Downloading the image locally and uploading it is a workaround, yes. Not ideal but it's simple. However, you won't need it for the migration to v2, I believe, since you can re-use existing images. Heat won't be able to create new images and have them point to external locations, though, unless the settings I mentioned above have been enabled.

>Also, glance location api could probably have been useful here. 
>However, we were advised in the earlier thread not to use it, as 
>exposing the location to the end user is perceived as a security risk.

++

Flavio

>
>[1]  
>http://lists.openstack.org/pipermail/openstack-dev/2016-May/094598.html
>
>
>Cheers,
>> Flavio
>>
>>
>>> [1] 
>>> https://wiki.openstack.org/wiki/Glance-v2-v1-client-compatability
>>> [2] https://github.com/openstack/heat/blob/master/heat/engine/
>>> resources/openstack/glance/image.py#L107-L112
>>>
>>>
>>> As an user, I need Glance v2 support so I can remove Glance Registry
>>>> from my deployment. and run pure v2 everywhere in my cloud.
>>>>
>>>> Thanks for your help,
>>>> --
>>>> Emilien Macchi
>>>>
>>>> ____________________________________________________________
>>>> ______________
>>>> OpenStack Development Mailing List (not for usage questions)
>>>> Unsubscribe: OpenStack-dev-request at lists.op 
>>>> enstack.org?subject:unsubscribe 
>>>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>>>>
>>>>
>>>
>>>
>>> --
>>> Regards,
>>> Rabi Misra
>>>
>>
>> _____________________________________________________________________
>> _____
>>> OpenStack Development Mailing List (not for usage questions)
>>> Unsubscribe: 
>>> OpenStack-dev-request at lists.openstack.org?subject:unsubscrib
>>> e
>>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>>>
>>
>>
>> --
>> @flaper87
>> Flavio Percoco
>>
>> _____________________________________________________________________
>> _____ OpenStack Development Mailing List (not for usage questions)
>> Unsubscribe: 
>> OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>>
>>
>
>
>--
>Regards,
>Rabi Misra

>_______________________________________________________________________
>___ OpenStack Development Mailing List (not for usage questions)
>Unsubscribe: 
>OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
>http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev


--
@flaper87
Flavio Percoco