bad default for my_ip if 8.8.8.8 is unreachable

[Mathew Odden]

The detection method for the configuration option my_ip seems to assume that 8.8.8.8 will always be routable from a compute host and chooses 127.0.0.1 as a fall back if there is no route to the google DNS (8.8.8.8)

See here:

https://github.com/openstack/nova/blob/master/nova/netconf.py#L38

Falling back to 127.0.0.1 doesn't seem useful, so I am wondering if there is a better option here.

Some pdb information while debugging:

> /usr/lib/python2.6/site-packages/nova/netconf2.py(40)_get_my_ip()
-> csock.connect(('8.8.8.8', 80))
(Pdb) n
error: (101, 'Network is unreachable')
> /usr/lib/python2.6/site-packages/nova/netconf2.py(40)_get_my_ip()
-> csock.connect(('8.8.8.8', 80))

[Russell Bryant (russellb)]

This is the kind of thing that's better to specify than let the app try to guess anyway, IMO.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/34389

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/34389
Committed: http://github.com/openstack/nova/commit/7b97d363524fbd471289070557d1b8ffe9c06758
Submitter: Jenkins
Branch: master

commit 7b97d363524fbd471289070557d1b8ffe9c06758
Author: Davanum Srinivas <email address hidden>
Date: Tue Jun 25 08:54:53 2013 -0400

    Better default for my_ip if 8.8.8.8 is unreachable

    Run if route/show, extract ipv4 addresses and pick the first one.
    Fall back to 127.0.0.1 as before if we don't find anything
    or if we have running the ip route/show commands

    Fixes LP# 1193013

    Change-Id: If73f0f6bf67f858f7506220debab0f74cc9e3cb4