Initial openstack image constraints

Initial openstack image constraints

This branch adds skeletal support for openstack image contraints.
The retrieval of the image id to use is abstracted away, and the API
is similar to that used for ec2 - specify a series, arch, region and get an
image id to use.

There's no http://cloud-images.ubuntu.com yet for openstack, so as a fallback
the user can specify an image id to use in their config. Like the case for
pyjuju, this "default-image-id" config defaults to "" so must be correctly
set up by the user for things to work.

https://code.launchpad.net/~wallyworld/juju-core/openstack-image-constraint/+merge/145302

(do not edit description out of merge proposal)

[wallyworld, 2013-01-29 04:08:08]

Please take a look.

[jameinel, 2013-01-29 13:10:30]

Overall seems ok, but it feels like we are missing unit tests for the
findInstanceId code. Is it possible to put in some whitebox testing of it?

https://codereview.appspot.com/7237048/diff/1/environs/openstack/config.go
File environs/openstack/config.go (right):

https://codereview.appspot.com/7237048/diff/1/environs/openstack/config.go#ne...
environs/openstack/config.go:41: "default-image-id":  defaultImageId,
Should the config item be called "default"? It seems like you would use a const
of "defaultImageId" but the entry in the config would just be "image-id".

I realize this is stemming from "default-series", so we could do it either way.

[gz, 2013-01-29 16:10:55]

LGTM

https://codereview.appspot.com/7237048/diff/1/environs/openstack/config.go
File environs/openstack/config.go (right):

https://codereview.appspot.com/7237048/diff/1/environs/openstack/config.go#ne...
environs/openstack/config.go:16: )
I think we probably shouldn't provide a default default here, and simply make
the configuration key mandatory, that's what pyjuju does.

https://codereview.appspot.com/7237048/diff/1/environs/openstack/config.go#ne...
environs/openstack/config.go:41: "default-image-id":  defaultImageId,
On 2013/01/29 13:10:30, jameinel wrote:
> Should the config item be called "default"?

The plan is to keep existing pyjuju configurations working with gojuju, so we're
stuck with some suboptimal configuration names, this is one of them.

https://codereview.appspot.com/7237048/diff/1/environs/openstack/image.go
File environs/openstack/image.go (right):

https://codereview.appspot.com/7237048/diff/1/environs/openstack/image.go#new...
environs/openstack/image.go:9: // chosen by the ec2 provider.
Not 'ec2' provider?

[wallyworld, 2013-01-30 00:25:17]

I've added some tests for findInstanceSpec as requested.

https://codereview.appspot.com/7237048/diff/1/environs/openstack/config.go
File environs/openstack/config.go (right):

https://codereview.appspot.com/7237048/diff/1/environs/openstack/config.go#ne...
environs/openstack/config.go:16: )
On 2013/01/29 16:10:55, gz wrote:
> I think we probably shouldn't provide a default default here, and simply make
> the configuration key mandatory, that's what pyjuju does.

Ok, seems reasonable. I'll defer to your more extensive knowledge here. TBH I
thought about making it mandatory but wasn't sure.

https://codereview.appspot.com/7237048/diff/1/environs/openstack/image.go
File environs/openstack/image.go (right):

https://codereview.appspot.com/7237048/diff/1/environs/openstack/image.go#new...
environs/openstack/image.go:9: // chosen by the ec2 provider.
On 2013/01/29 16:10:55, gz wrote:
> Not 'ec2' provider?

Done.

[wallyworld, 2013-01-30 00:29:45]

*** Submitted:

Initial openstack image constraints

This branch adds skeletal support for openstack image contraints.
The retrieval of the image id to use is abstracted away, and the API
is similar to that used for ec2 - specify a series, arch, region and get an
image id to use.

There's no http://cloud-images.ubuntu.com yet for openstack, so as a fallback
the user can specify an image id to use in their config. Like the case for
pyjuju, this "default-image-id" config defaults to "" so must be correctly
set up by the user for things to work.

R=jameinel, gz
CC=
https://codereview.appspot.com/7237048