support libvirt provider

[varac]

hi,

i'm using sahara for quite some time, it's great !
i would liek to migrate from virtualbox to libvirt, using vagrant-libvirt (https://github.com/pradels/vagrant-libvirt).
i noticed that sahara is bound to virtualbox, and i's like to know if there are plans to support libvirt.

right now, it just exits with:

vagrant sandbox on couch1
sh: 1: VBoxManage: not found
sh: 1: VBoxManage: not found

[varac]

cool, looks like sciurus is working on support for vagrant-libvirt to sahara, see https://github.com/sciurus/sahara/commits/abstract_provider (and vagrant-libvirt/vagrant-libvirt#73 (comment)).

[sciurus]

I have a version of sahara at sciurus/sahara/tree/abstract_provider where I've reworked sahara's "session" implementation. I moved the generic logic into the commands themselves, keeping (mostly) just the virtualbox-specific code in the session. Instead of always loading support for virtualbox, I check the provider in use for each machine and try to load a session class that supports it.

@jedi4ever Comments on my approach and any changes you'd like to see would be highly appreciated.

I'm just getting started on writing a class that adds support for libvirt. I'll push another branch with it when it's working.

[ryuzee]

libvirt provider was already merged so that we can close this issue.