String and Symbol types are different when used as a Hash key. By
default the Vagrant machine names are set in Symbol format, but users
may write their `host_vars` entries with String keys. This is a very
simple way to ensure smooth experience, without having to coerce the
data types during the config validation (e.g. with a library like
Hashie, which is currently not in the Vagrant dependencies)
See also:
- https://bugs.ruby-lang.org/issues/5964#note-17
- https://github.com/intridea/hashie#keyconversion
With this change, the existing host-based Ansible provisioner is
refactored to share a maximum of code with this new guest-based Ansible
provisioner.
At this stage of development, the existing unit tests are intentionally
modified as little as possible, to keep safe the existing funtionalities.
Other issues resolved by this changeset:
- Display a warning when running from a Windows host [GH-5292]
- Do not run `ansible-playbook` in verbose mode when the `verbose` option
is set to an empty string.