Run Ansible on the Vagrant guest if you're on Windows.

Vagrantfile

Vagrant.configure(2) do |config|
  config.vm.box = "centos/7"

  # These lines are for testing gatling-rsync-auto on Windows; you can probably comment
  # them out and just have ansible-playbook look for /vagrant/playbook.yml.
  config.vm.synced_folder "files", "/opt/vagrant/rsynced_folder", type: "rsync"
  config.gatling.rsync_on_startup = true

  # On Windows, run ansible in the VM.
  if RUBY_PLATFORM =~ /mswin|mingw|cygwin/ then
    config.vm.provision "shell", inline: <<EOF
yum -y install epel-release
yum -y update
yum -y install ansible
ansible-playbook -i "localhost," -c local /home/vagrant/sync/playbook.yml
EOF
  else
    config.vm.provision "ansible"
  end
end