environs: Add EnvironCapability.SupportNetworks()

environs: Add EnvironCapability.SupportNetworks()

This provides a way to ask early if an environment
supports the networking operations we need for VLANs.
All providers, except MAAS and dummy return false for
that.

For MAAS used the newly created /version/ endpoint
(in r2188, see bug #1297814) to check if support is
there or not.

In a follow-up we can finish the CLI changes now,
with --networks / --no-networks arguments for deploy.

https://code.launchpad.net/~dimitern/juju-core/365-environs-supportnetworks/+merge/213262

(do not edit description out of merge proposal)

[dimitern, 2014-03-28 13:36:23]

Please take a look.

[fwereade, 2014-03-28 13:43:33]

LGTM

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ.go
File provider/maas/environ.go (right):

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ.go#newco...
provider/maas/environ.go:160: logger.Debugf(err.Error())
bit more context here please

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ_whitebox...
File provider/maas/environ_whitebox_test.go (right):

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ_whitebox...
provider/maas/environ_whitebox_test.go:531: // once gomaasapi testing server
supports networks.
That looks like a good next step :).

[vladislav.klyachin, 2014-03-28 14:14:04]

LGTM

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ.go
File provider/maas/environ.go (right):

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ.go#newco...
provider/maas/environ.go:156: // SupportedArchitectures is specified on the
EnvironCapability interface.
s/SupportedArchitectures/SupportNetworks/

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ.go#newco...
provider/maas/environ.go:175: func (env *maasEnviron) getCapabilities()
([]string, error) {
may be func (*maasEnviron) getCapabilities() (map[string]bool, error) is better

[dimitern, 2014-03-28 14:58:08]

Please take a look.

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ.go
File provider/maas/environ.go (right):

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ.go#newco...
provider/maas/environ.go:160: logger.Debugf(err.Error())
On 2014/03/28 13:43:34, fwereade wrote:
> bit more context here please

Done.

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ_whitebox...
File provider/maas/environ_whitebox_test.go (right):

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ_whitebox...
provider/maas/environ_whitebox_test.go:531: // once gomaasapi testing server
supports networks.
On 2014/03/28 13:43:34, fwereade wrote:
> That looks like a good next step :).

Yeah, it's tested live, but we'll need to unit-test it as well. For that we need
gomaasapi changes.

[dimitern, 2014-03-28 15:12:39]

Please take a look.

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ.go
File provider/maas/environ.go (right):

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ.go#newco...
provider/maas/environ.go:156: // SupportedArchitectures is specified on the
EnvironCapability interface.
On 2014/03/28 14:14:05, vladislav.klyachin wrote:
> s/SupportedArchitectures/SupportNetworks/

Done.

https://codereview.appspot.com/81550046/diff/1/provider/maas/environ.go#newco...
provider/maas/environ.go:175: func (env *maasEnviron) getCapabilities()
([]string, error) {
On 2014/03/28 14:14:05, vladislav.klyachin wrote:
> may be func (*maasEnviron) getCapabilities() (map[string]bool, error) is
better

I was thinking about that - in fact I'll use set.Strings, which uses
map[string]bool underneath.

[fwereade, 2014-03-28 16:24:36]

set.Strings looks eminently suitable, LGTM