I agree with Jay. The extension layer is also expensive in CPU usage, and it also makes more difficult to troubleshoot issues.
----- Original Message ----- > From: "Jay Pipes" <jaypi...@gmail.com> > To: "OpenStack Development Mailing List" <openstack-dev@lists.openstack.org>, > "Sergey Nikitin" > <sniki...@mirantis.com> > Sent: Sunday, March 8, 2015 1:31:34 AM > Subject: [openstack-dev] [nova][api] Microversions. And why do we need API > extensions for new API functionality? > > Hi Stackers, > > Now that microversions have been introduced to the Nova API (meaning we > can now have novaclient request, say, version 2.3 of the Nova API using > the special X-OpenStack-Nova-API-Version HTTP header), is there any good > reason to require API extensions at all for *new* functionality. > > Sergey Nikitin is currently in the process of code review for the final > patch that adds server instance tagging to the Nova API: > > https://review.openstack.org/#/c/128940 > > Unfortunately, for some reason I really don't understand, Sergey is > being required to create an API extension called "os-server-tags" in > order to add the server tag functionality to the API. The patch > implements the 2.4 Nova API microversion, though, as you can see from > this part of the patch: > > https://review.openstack.org/#/c/128940/43/nova/api/openstack/compute/plugins/v3/server_tags.py > > What is the point of creating a new "plugin"/API extension for this new > functionality? Why can't we just modify the > nova/api/openstack/compute/server.py Controller.show() method and > decorate it with a 2.4 microversion that adds a "tags" attribute to the > returned server dictionary? > > https://github.com/openstack/nova/blob/master/nova/api/openstack/compute/servers.py#L369 > > Because we're using an API extension for this new server tags > functionality, we are instead having the extension "extend" the server > dictionary with an "os-server-tags:tags" key containing the list of > string tags. > > This is ugly and pointless. We don't need to use API extensions any more > for this stuff. > > A client knows that server tags are supported by the 2.4 API > microversion. If the client requests the 2.4+ API, then we should just > include the "tags" attribute in the server dictionary. > > Similarly, new microversion API functionality should live in a module, > as a top-level (or subcollection) Controller in > /nova/api/openstack/compute/, and should not be in the > /nova/api/openstack/compute/plugins/ directory. Why? Because it's not a > plugin. > > Why are we continuing to use these awkward, messy, and cumbersome API > extensions? > > Please, I am begging the Nova core team. Let us stop this madness. No > more API extensions. > > Best, > -jay > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
