Comment 1 for bug 1450729

> Unless there is something I'm not foreseeing, I think that if a node is just allocated in MAAS, it should be seen as available by juju
> if juju has the same API credentials as the user who allocated the node.

Technically there is nothing preventing Juju from using a previously allocated node. Now, it gets a bit complicated if you consider that the constraints are used during the acquisition phase: once a node is acquired, there is no record of the set of constraints that got it acquired in the first place.