support ~/.juju/environments.d

[Sidnei da Silva]

It's nice that ~/.juju/environments.yaml is structured and all that, but would be much nicer if one could add/remove environment configs by adding/deleting a file under ~/.juju/environments.d/<name>.yaml instead.

[Dave Cheney (dave-cheney)]

Hello,

For the 1.9.12 release the juju cli tool now supports a JUJU_HOME environment variable. This defaults to $HOME/.juju but can be used to switch between juju configurations.

Please let me know if you find this sufficient.

[William Reade (fwereade)]

I think this is a distinct and valid use case.

[Cheryl Jennings (cherylj)]

With Juju 2.0, there is no longer a need for environments.yaml. Public clouds are "built in" and private clouds can be defined using `juju add-cloud`.

Bootstrapping additional controllers doesn't require additional configuration, just specify a different name at bootstrap time.