vagrant/plugins/guests/alpine/cap/rsync.rb

module VagrantPlugins
  module GuestAlpine
    module Cap
      class RSync
        def self.rsync_installed(machine)
          machine.communicate.test('test -f /usr/bin/rsync')
        end

        def self.rsync_install(machine)
          machine.communicate.tap do |comm|
            comm.sudo('apk add --update-cache rsync')
          end
        end
      end
    end
  end
end