Code review comment for lp://staging/~wallyworld/juju-core/simplestreams-multiple-indices

*** Submitted:

Use multiple base urls for simplestreams

The simplestreams image metadata lookup now takes multiple base urls,
and looks at each
in turn to try and find an index file containing the requested image.
The order of looking
is:
- public bucket (if openstack)
- product-streams keystone catalog entry (if openstack)
- default cloud-images.ubuntu.com url

The ec2 and openstack providers have been configured to generate the
above urls. The next
branch will use these urls and the simplestreams support to find the
image id for the
relevant image based on series, arch etc.

R=jameinel, fwereade, TheMue
CC=
https://codereview.appspot.com/9128047

https://codereview.appspot.com/9128047/