Add option vagrant_prefer_nfs

[tangrufus]

On Macs that using APFS, vagrant up gives:

==> default: Mounting NFS shared folders...
The following SSH command responded with a non-zero exit status.
Vagrant assumes that this means the command failed!
mount -o vers=3,udp 192.168.50.1:/Users/XXX/Code/site /vagrant-nfs-example.com
Stdout from the command:
Stderr from the command:
mount.nfs: access denied by server while mounting 192.168.50.1:/Users/XXX/Code/site

See:

• NFS folders not properly synced on macOS High Sierra hashicorp/vagrant#8788
• Failing to install Drupal on macOS High Sierra - NFS filesystem issues geerlingguy/drupal-vm#1547

This pull request adds vagrant_prefer_nfs option so that non-windows users could have a choice to use default synced_folder type.

Only tested with vagrant 1.9.8 + macOS 10.13 + APFS.

For APFS user:

1. Set vagrant_prefer_nfs: false
2. FORCE_ANSIBLE_LOCAL=true vagrant up

Note: This won't work on vagrant 2.0, see: https://discourse.roots.io/t/the-requested-ansible-version-2-4-0-was-not-found-on-the-guest/10513

Discuss:

• Should we implicitly set ansible_local when vagrant_prefer_nfs: false(like what we are doing for windows users)?
• Bring back Use ansible_local provisioner on all platforms #439?

[swalkinshaw]

re: #439, we did enable ansible-local by default 😄

I'm fine with adding this option regardless. Is there no better solution for APFS yet?

[tangrufus]

we did enable ansible-local by default

Is that true for non-wondows users?
https://github.com/roots/trellis/blob/master/lib/trellis/vagrant.rb#L40-L42

Is there no better solution for APFS yet?

I don't find one.

Please test this pull request on non-APFS Macs and other platforms.

[swalkinshaw]

Is that true for non-windows users?

Yep 👍

[tangrufus]

# https://github.com/roots/trellis/blob/master/lib/trellis/vagrant.rb#L40-L42

def local_provisioning?
  @local_provisioning ||= Vagrant::Util::Platform.windows? || !which('ansible-playbook') || ENV['FORCE_ANSIBLE_LOCAL']
end

To use Trellis for remote servers, we recommend installing Ansible locally on your host machine
https://roots.io/trellis/docs/remote-server-setup/

If Ansible is installed as the doc suggests, ansiable_local is not used.

[swalkinshaw]

Yeah, sorry I just meant it's the default for everyone. If someone follows our docs as of now, they'd get ansible local.

[swalkinshaw]

Is this PR useful as is?

Or does it depend on:

Should we implicitly set ansible_local when vagrant_prefer_nfs: false(like what we are doing for windows users)?

[tangrufus]

After moving to a SSD harddisk, trellis works out of the box. I think this pull request should not be merged and APFS on traditional harddisk users should manually disable NFS and use ansible_local.