Add instance IP to to /instances

[Mat Lowery]

We've noticed some slowness during Trove instance list in Horizon. From my research, it appears that Horizon performs the following calls when rendering the list with the number before the colon being the count of the number of calls.

1:/v1.0/<tenant_id>/instances?limit=20
1:/v1.0/<tenant_id>/flavors
N:/v1.0/<tenant_id>/instances/<uuid_for_instance_n>

That last "call per Trove instance" is the cause of the slowness. The only reason it needs to make that call per Trove instance is to get the instance IP. This call per row contrasts with Nova servers listing in Horizon which uses only "batch" calls (i.e. constant number of calls per page).

From SlickNik:
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Seeing as to how we're already talking to nova during a list command, perhaps the simplest and most convenient thing to do here is to add the IP addresses to the view, so that horizon is able to display that information without an additional click.

Hopefully the IP address information does come back as part of the nova list servers command (IIRC it does, but wouldn't hurt to verify). If that's the case, I'm totally fine with a adding this information to the trove list view response.
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Nova servers are already being fetched here:

http://git.io/WoOSlg

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/105632

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/105632
Committed: https://git.openstack.org/cgit/openstack/trove/commit/?id=af74e78f2de0f6f36e9319a14a58298c63996dc4
Submitter: Jenkins
Branch: master

commit af74e78f2de0f6f36e9319a14a58298c63996dc4
Author: svenkataramanaia <email address hidden>
Date: Tue Jul 8 16:53:27 2014 -0700

    Add instance IP to /instances

    This new response will be used by Horizon instead of the 1+N calls
    Horizon makes today in order to render IPs in the instances list

    Change-Id: Ice8f07cdaf873034dc7dc8840fcc403b4756ac12
    Closes-Bug: #1339400