Standardize Nova Image¶
https://blueprints.launchpad.net/nova/+spec/standardize-nova-image
Standardize Nova’s nova.image module to work like nova.network.api and nova.volume.cinder.
Problem description¶
For some reason, nova.image does things differently than nova.volume and nova.network. Instead of nova.compute.manager instantiating a self.image_api object, like it does for self.network_api and self.volume_api, the compute manager calls an obtuse collection of nova.image.glance module calls.
This blueprint is around the work to make a new nova.image.api module and have it called like other submodule “internal APIs” in Nova.
Proposed change¶
A new nova.image.api module shall be created, following in the style of nova.network.api and nova.volume.cinder. There will be an API class in the nova.image.api module that follows identical conventions as the nova.volume.cinder.API class, with methods for listing (get_all), showing (get), creating (create), updating (update), and removing (delete) images from the backend image store. There will be a nova.image.driver module with a base driver class.
The nova.image.glance module will be updated to subclass the base driver class.
Alternatives¶
There is a series of patches in review up for Nova that tries to add support for Glance’s V2 API operations:
Unfortunately, I believe this patch series further muddies the image service inside Nova instead of making it cleaner and standardized with the rest of Nova’s external API interfaces.
The idea of this blueprint is to lay a good foundation for future V2 Glance API work by first standardizing the image API inside of Nova.
Data model impact¶
None
REST API impact¶
None
Security impact¶
None
Notifications impact¶
None
Other end user impact¶
None
Performance Impact¶
None
Other deployer impact¶
None
Developer impact¶
See above link to Eddie Sheffield’s patch series that would be affected by the code in this blueprint. Hopefully, however, once the image API is brought in line with the other internal-to-external Nova APIs, the work on V2 Glance API should be quite a bit easier.
Implementation¶
Assignee(s)¶
- Primary assignee:
jaypipes
Work Items¶
Create the nova.image.api module that instantiates a driver
Create the base image driver class, modeling after the new nova.network.driver class created by the refactor-network-api blueprint code.
Move the existing glance code into a subclassed driver
Dependencies¶
None
Testing¶
None
Documentation Impact¶
None
References¶
None
