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<p><font size="2" face="sans-serif">Hi stackers,</font><br>
<br>
<font size="2" face="sans-serif">Now I'm running into an issue about reusing image id in Glance. Based on current design, the image id can be specified during create image by end user. But now there is a problem, which is tracked by defect </font><a href="https://bugs.launchpad.net/glance/+bug/1176978"><font size="1" color="#0000FF" face="Arial"><u>https://bugs.launchpad.net/glance/+bug/1176978</u></font></a><font size="2" face="sans-serif">. In summary, if user want to port an image from VMware vCenter which has been used by many VMs. So when user port the image into Glance, it would be nice if the original image id with UUID format from vCenter can be used. But if the image is removed and recreated again, he will run into current issue. I have discussed it with flaper87 in Glance IRC channel, below is the chat log. FYI. And I also attached the patch, please help review it. Any comment/suggestion is welcome. Thanks.</font><br>
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<font size="2" face="sans-serif">Chat log between flaper87 and me.</font><br>
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<font size="2" color="#16569E" face="serif">(07:46:34 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> btw, may I get your thought about this defect? </font><a href="https://bugs.launchpad.net/glance/+bug/1176978"><font size="3" color="#0000FF" face="serif"><u>https://bugs.launchpad.net/glance/+bug/1176978</u></font></a><font size="2" color="#16569E" face="serif"><br>
(07:47:48 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> about if the image id should be reused after the image is deleted</font><font size="2" color="#A82F2F" face="serif"><br>
(07:49:18 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> flwang: it shouldn't, images are never *truly* deleted, see </font><a href="https://github.com/openstack/glance/blob/master/glance/db/sqlalchemy/models.py#L65"><font size="3" color="#0000FF" face="serif"><u>https://github.com/openstack/glance/blob/master/glance/db/sqlalchemy/models.py#L65</u></font></a><font size="2" color="#16569E" face="serif"><br>
(07:49:27 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> I see</font><font size="2" color="#A82F2F" face="serif"><br>
(07:49:39 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> that's the BaseModel</font><font size="2" color="#16569E" face="serif"><br>
(07:49:43 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> I know it's just marked 1 in the deleted column</font><font size="2" color="#A82F2F" face="serif"><br>
(07:49:45 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> and Image inherits from it</font><font size="2" color="#A82F2F" face="serif"><br>
(07:49:52 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> correct</font><font size="2" color="#A82F2F" face="serif"><br>
(07:50:21 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> there were some discussions about completely delelting those images (cleaning up the db)</font><font size="2" color="#16569E" face="serif"><br>
(07:50:23 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> now there is a scenario</font><font size="2" color="#A82F2F" face="serif"><br>
(07:50:34 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> but nothing has been decided yet</font><font size="2" color="#A82F2F" face="serif"><br>
(07:51:28 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> TBH, I don't like the idea of people passing the id on the create command, but that's another story for another time</font><font size="2" color="#16569E" face="serif"><br>
(07:51:30 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> user is porting some images from vmware vcenter, and then these images are deleted</font><font size="2" color="#A82F2F" face="serif"><br>
(07:51:49 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> flwang: not sure I understand</font><font size="2" color="#A82F2F" face="serif"><br>
(07:52:00 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> flwang: you mean, import image from vmware into glance</font><font size="2" color="#16569E" face="serif"><br>
(07:52:04 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> but next, user want to add these images again with the image id given by vcenter</font><font size="2" color="#A82F2F" face="serif"><br>
(07:52:05 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> then delete image in glance</font><font size="2" color="#16569E" face="serif"><br>
(07:52:09 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> yes</font><font size="2" color="#16569E" face="serif"><br>
(07:53:20 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> anyway, if user want to re-register an image with its given id from other place, he will run into problem based on current code</font><font size="2" color="#A82F2F" face="serif"><br>
(07:54:10 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> flwang: yep, I guess passing the ID makes sense when you've 3K services pointing to that specific ID and you want them to use glance</font><font size="2" color="#16569E" face="serif"><br>
(07:54:35 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> exactly</font><font size="2" color="#A82F2F" face="serif"><br>
(07:55:19 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> mmh, interesting. I'm trying to find the bp / discussion about "really deleting" images. I can't find it</font><font size="2" color="#16569E" face="serif"><br>
(07:58:04 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> for short term, I want to reuse the id</font><font size="2" color="#16569E" face="serif"><br>
(07:59:03 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> when create new image, glance will try to check if there is a dead image if there is a given image id</font><font size="2" color="#16569E" face="serif"><br>
(07:59:14 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> if yes, reuse id</font><font size="2" color="#16569E" face="serif"><br>
(07:59:55 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> any concern?</font><font size="2" color="#A82F2F" face="serif"><br>
(08:00:01 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> might make sense. It would be cool if you could write this to the mailing list so that other folks can comment. Make sure your point the use-cases and ideas there</font><font size="2" color="#062585" face="serif"><br>
(08:00:19 AM)</font><font size="3" color="#062585" face="serif"> </font><font size="3" color="#062585" face="serif"><b>***flaper87</b></font><font size="3" face="serif"> is still trying to find that stuff</font><font size="2" color="#A82F2F" face="serif"><br>
(08:00:22 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> arrgh</font><font size="2" color="#A82F2F" face="serif"><br>
(08:00:24 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> internet is sooo big</font><font size="2" color="#16569E" face="serif"><br>
(08:02:23 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> good suggestion, I will send it to mailing list. Actually, I have worked out the patch, and I think it works fine.</font><font size="2" color="#A82F2F" face="serif"><br>
(08:03:57 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> If you have some code to show, I'd suggest to either push it somewhere in GH or submitting the patch (thing is that this change, most likely, requires a blueprint so, I'd rather get some feedback before going down that road)</font><font size="2" color="#16569E" face="serif"><br>
(08:13:45 AM)</font><font size="3" color="#16569E" face="serif"> </font><font size="3" color="#16569E" face="serif"><b>flwang:</b></font><font size="3" face="serif"> I'm going to submit the patch as the fix of this bug, make sense?</font><font size="2" color="#A82F2F" face="serif"><br>
(08:14:30 AM)</font><font size="3" color="#A82F2F" face="serif"> </font><font size="3" color="#A82F2F" face="serif"><b>flaper87:</b></font><font size="3" face="serif"> mmh, yeah, that makes sense. Expect some discussions, though. </font><br>
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<font size="2" face="sans-serif">diff -rupN glance-unpatched/glance/db/sqlalchemy/api.py glance/glance/db/sqlalchemy/api.py</font><br>
<font size="2" face="sans-serif">--- glance-unpatched/glance/db/sqlalchemy/api.py 2013-04-17 19:45:48.175132054 -0500</font><br>
<font size="2" face="sans-serif">+++ glance/glance/db/sqlalchemy/api.py 2013-04-17 19:46:03.905136572 -0500</font><br>
<font size="2" face="sans-serif">@@ -235,7 +235,34 @@ def wrap_db_error(f):</font><br>
<font size="2" face="sans-serif"> </font><br>
<font size="2" face="sans-serif"> def image_create(context, values):</font><br>
<font size="2" face="sans-serif"> """Create an image from the values dictionary."""</font><br>
<font size="2" face="sans-serif">- return _image_update(context, values, None, False)</font><br>
<font size="2" face="sans-serif">+ image_id = values.get('id', None)</font><br>
<font size="2" face="sans-serif">+ if image_id:</font><br>
<font size="2" face="sans-serif">+ session = get_session()</font><br>
<font size="2" face="sans-serif">+ with session.begin():</font><br>
<font size="2" face="sans-serif">+ # The create image request comes with an ID, since these are</font><br>
<font size="2" face="sans-serif">+ # supposed to be universal IDs, this may mean that a user is</font><br>
<font size="2" face="sans-serif">+ # trying to re-add an image that he had previously deleted.</font><br>
<font size="2" face="sans-serif">+ # Let's let him do that, by "undeleting" the image.</font><br>
<font size="2" face="sans-serif">+ try:</font><br>
<font size="2" face="sans-serif">+ dead_image = _image_get(context,</font><br>
<font size="2" face="sans-serif">+ image_id,</font><br>
<font size="2" face="sans-serif">+ session=session,</font><br>
<font size="2" face="sans-serif">+ force_show_deleted=True)</font><br>
<font size="2" face="sans-serif">+ LOG.debug("Dead Image: %s" % dead_image.deleted)</font><br>
<font size="2" face="sans-serif">+ if dead_image.deleted:</font><br>
<font size="2" face="sans-serif">+ LOG.info("Image '%s' had been deleted before "</font><br>
<font size="2" face="sans-serif">+ "and will be reactivated." % image_id)</font><br>
<font size="2" face="sans-serif">+ dead_image.undelete(session=session)</font><br>
<font size="2" face="sans-serif">+ except exception.NotFound:</font><br>
<font size="2" face="sans-serif">+ LOG.debug("Adding new image with user provided "</font><br>
<font size="2" face="sans-serif">+ "UUID '%s'" % image_id)</font><br>
<font size="2" face="sans-serif">+ # Not really a failure, this just means the user provided a</font><br>
<font size="2" face="sans-serif">+ # UUID for the very first time, still let's null it out</font><br>
<font size="2" face="sans-serif">+ # for _image+_update() because even if the user provided</font><br>
<font size="2" face="sans-serif">+ # an ID, this method does not expect the ID here when creating</font><br>
<font size="2" face="sans-serif">+ # new images</font><br>
<font size="2" face="sans-serif">+ image_id = None</font><br>
<font size="2" face="sans-serif">+ return _image_update(context, values, image_id, False)</font><br>
<font size="2" face="sans-serif"> </font><br>
<font size="2" face="sans-serif"> </font><br>
<font size="2" face="sans-serif"> def image_update(context, image_id, values, purge_props=False):</font><br>
<font size="2" face="sans-serif">diff -rupN glance-unpatched/glance/db/sqlalchemy/models.py glance/glance/db/sqlalchemy/models.py</font><br>
<font size="2" face="sans-serif">--- glance-unpatched/glance/db/sqlalchemy/models.py 2013-04-27 19:45:48.175132054 -0500</font><br>
<font size="2" face="sans-serif">+++ glance/glance/db/sqlalchemy/models.py 2013-04-17 19:46:03.918174498 -0500</font><br>
<font size="2" face="sans-serif">@@ -66,6 +66,13 @@ class ModelBase(object):</font><br>
<font size="2" face="sans-serif"> self.deleted_at = timeutils.utcnow()</font><br>
<font size="2" face="sans-serif"> self.save(session=session)</font><br>
<font size="2" face="sans-serif"> </font><br>
<font size="2" face="sans-serif">+ def undelete(self, session=None):</font><br>
<font size="2" face="sans-serif">+ """Undelete this object"""</font><br>
<font size="2" face="sans-serif">+ self.deleted = False</font><br>
<font size="2" face="sans-serif">+ self.deleted_at = None</font><br>
<font size="2" face="sans-serif">+ self.status = 'active'</font><br>
<font size="2" face="sans-serif">+ self.save(session=session)</font><br>
<font size="2" face="sans-serif">+</font><br>
<font size="2" face="sans-serif"> def update(self, values):</font><br>
<font size="2" face="sans-serif"> """dict.update() behaviour."""</font><br>
<font size="2" face="sans-serif"> for k, v in values.iteritems():</font><br>
<br>
<br>
<br>
<font size="2" face="sans-serif">Thanks & Best regards,<br>
Fei Long Wang (Íõ·ÉÁú)<br>
--------------------------------------------------<br>
Scrum Master, Cloud Solutions and OpenStack Development<br>
Tel: 8610-82450513 | T/L: 905-0513 <br>
Email: flwang@cn.ibm.com<br>
China Systems & Technology Laboratory in Beijing<br>
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