Scrub Guest Paths for Windows Rsync leaving Dirty Paths for Winrm Mkdir

Windows offers no out-of-the-box rsync utility. By far, the most
commonly used external utilities for Windows rsync are built with the
GNU Cygwin libraries. The cost for this convenience is that rsync on
Windows has to be provided paths that begin “/cygdrive/c” rather than
“c:/“ like other Windows-API utilities. Compounding the situation,
rsync doesn’t create paths/to/sub/targets and so the vagrant plugin
code, when performing an rsync, is responsible for creating
intermediate directories in guest paths if there are any. Furthermore,
the mkdir utility in Windows is not another Cygwin utility like rsync
but the routine mkdir of Windows command.com. Therefore, while rsync
needs the /cygwin paths, mkdir uses the Windows paths. Later, the
chef_solo.rp provisioner running within the guest will expect to find
Windows-style paths in its solo.rb configuration file. Due to all this,
vagrant has to keep track of both the original, possibly dirty Windows
guest path and the cygwin-scrubbed guest path.

plugins/guests/windows/cap/rsync.rb

@@ -2,8 +2,17 @@ module VagrantPlugins
   module GuestWindows
     module Cap
       class RSync
+        def self.rsync_scrub_guestpath( machine, opts )
+          # Windows guests most often use cygwin-dependent rsync utilities
+          # that expect "/cygdrive/c" instead of "c:" as the path prefix
+          # some vagrant code may pass guest paths with drive-lettered paths here
+          opts[:guestpath].gsub( /^([a-zA-Z]):/, '/cygdrive/\1' )
+        end
+
         def self.rsync_pre(machine, opts)
           machine.communicate.tap do |comm|
+            # rsync does not construct any gaps in the path to the target directory
+            # make sure that all subdirectories are created
             comm.execute("mkdir '#{opts[:guestpath]}'")
           end
         end

plugins/guests/windows/plugin.rb

@@ -64,6 +64,11 @@ module VagrantPlugins
         Cap::MountSharedFolder
       end
 
+      guest_capability(:windows, :rsync_scrub_guestpath) do
+        require_relative "cap/rsync"
+        Cap::RSync
+      end
+
       guest_capability(:windows, :rsync_pre) do
         require_relative "cap/rsync"
         Cap::RSync

plugins/synced_folders/rsync/helper.rb

@@ -38,6 +38,11 @@ module VagrantPlugins
         hostpath  = File.expand_path(hostpath, machine.env.root_path)
         hostpath  = Vagrant::Util::Platform.fs_real_path(hostpath).to_s
 
+        # if the guest has a guest path scrubber capability, use it
+        if machine.guest.capability?(:rsync_scrub_guestpath)
+          guestpath = machine.guest.capability(:rsync_scrub_guestpath, opts)
+        end
+
         if Vagrant::Util::Platform.windows?
           # rsync for Windows expects cygwin style paths, always.
           hostpath = Vagrant::Util::Platform.cygwin_path(hostpath)