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<p><font size="2" face="sans-serif">Current Nova uses the v1 APIs [1] of Glance when taking snapshots, which can cause issues when v2 of the API is used to place properties on the image longer than 255 characters [2].</font><br>
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<font size="2" face="sans-serif">Summarizing bug 1117923:</font><br>
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<font size="2" face="sans-serif">1) A new migration script is needed in nova to change the "varchar(255)" datatype on the "value" column in nova.instance_system_metadata to "text" to match the "text" datatype on the value column in glance.image_properties</font><br>
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<font size="2" face="sans-serif">2) Implement create/update in the v2 implementation used by glanceclient</font><br>
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<font size="2" face="sans-serif">3) Change nova/image/glance.py to use v2 of glanceclient. </font><br>
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<font size="2" face="sans-serif">My understanding is that the the v2 API will not be enabled by default in this release. Consequently, Nova cannot assume that the v2 API will be present. I proposed up a patch [3] that provided a configuration option for the administrator to change if the Glance endpoint supported v2. It is not the ideal solution, rather Rusell Bryant correctly identified it as using the service catalog to discover the API to use. </font><br>
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<font size="2" face="sans-serif">What is the right fix this late in the development cycle? At first pass, it seems that the negotiation between the client / server and / or Keystone on the API version would be a non-trival code effort and require substantial changes to nova/image/glance.py to exploit. The current patch is fairly trivial at the expense of introducing a config option that is likely to be deprecated in the next release or two. </font><br>
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<font size="2" face="sans-serif">[1] <a href="https://github.com/openstack/nova/blob/master/nova/image/glance.py#L286">https://github.com/openstack/nova/blob/master/nova/image/glance.py#L286</a></font><br>
<font size="2" face="sans-serif">[2] </font><font size="2" face="sans-serif"><a href="https://bugs.launchpad.net/nova/+bug/1117923">https://bugs.launchpad.net/nova/+bug/1117923</a></font><br>
<font size="2" face="sans-serif">[3] <a href="https://review.openstack.org/#/c/21850/">https://review.openstack.org/#/c/21850/</a></font><br>
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Michael</font><br>
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Michael Fork<br>
OpenStack Architect, Cloud Solutions and OpenStack Development<br>
IBM Systems & Technology Group</font></body></html>