[feature request] map juju models to MaaS Resource pools

[Hybrid512]

Hi,

MaaS + Juju is a very nice combo, however, playing with dozens of physical/virtual machines makes it quite hard to filter machines per models deployments.

It is not possible, through the MaaS UI/API, to easily display only the machines devoted to on specific model.
You can of course find them by corelating with Juju status but this is not trivial at all.
In MaaS, there is a concept of "Resource Pools" which is a way to group machines together and filter them base on this criteria.
Typically, this is very usefull when you deploy 10 VMs for a project, you just create a resource pool with the name of your project then deploy your VMs, you can then easily find those VMs in the machines list by just filtering on this resource pool name.
I find it very similar to the "model" concept we find in Juju and thus, it would be very to map a juju model to a maas resource pool.

A simple use case would be this :
* have plenty of machines in ready state in MaaS
* in Juju, creating a new model on a MaaS cloud would create a resource pool in MaaS with the same name and trigger an alert if there is already a resource pool by that name
* deploy your application in your model on some machines, those machines would then be mapped to this MaaS resource pool so that they can be easily found in the MaaS UI
* when deleting the model, delete the resource pool in MaaS

This is for MaaS provider only but I suppose similar things exists with other Cloud providers.

Best regards.