Model config

[Ian Booth]

On 08/06/16 23:59, roger peppe wrote:
> On 8 June 2016 at 10:41, Andrew Wilkins <andrew.wilkins at canonical.com> wrote:
>> Hi folks,
>>
>> We're in the midst of making some changes to model configuration in Juju
>> 2.0, separating out things that are not model specific from those that are.
>> For many things this is very clear-cut, and for other things not so much.
>>
>> For example, api-port and state-port are controller-specific, so we'll be
>> moving them from model config to a new controller config collection. The end
>> goal is that you'll no longer see those when you type "juju
>> get-model-config" (there will be a separate command to get controller
>> attributes such as these), though we're not quite there yet.
> 
> Interesting - seems like a good change.
> 
> Will this change the internal and API representations too, so there
> are two groups
> of mutually-exclusive attributes? Does this also mean that the

Internally there will be three groups of mutually exclusive attributes:
- controller
- cloud
- model

Initially, we'll maintain internal API compatibility by combining all these to
produce the result of state.ModelConfig()

We'll then be able to consider things like config inheritance / overrides etc.
eg if cloud config (specified in the clouds.yaml file) defines an apt-mirror,
should we allow a model to also have that value, which will take precedence over
the cloud value.

> really-not-very-nice
> ConfigSkeleton API method will go too?
> 

I hope so. But we're rushing to get everything done for beta9 and are focusing
first on the data model since it will be harder to upgrade if that's not right
first up.