synced_folders/smb: verify PowerShell v3 is running or later [GH-3257]

CHANGELOG.md

@@ -7,6 +7,7 @@ IMPROVEMENTS:
     to convey actual meaning.
   - commands/plugin: Listing plugins now has machine-readable output. [GH-3293]
   - guests/omnios: Mount NFS capability [GH-3282]
+  - synced\_folders/smb: Verify PowerShell v3 or later is running. [GH-3257]
 
 BUG FIXES:
 

lib/vagrant/util/powershell.rb

@@ -31,6 +31,22 @@ module Vagrant
 
         Subprocess.execute(*command, &block)
       end
+
+      # Returns the version of PowerShell that is installed.
+      #
+      # @return [String]
+      def self.version
+        command = [
+          "powershell",
+          "-NoProfile",
+          "-ExecutionPolicy", "Bypass",
+          "$PSVersionTable.PSVersion.Major"
+        ].flatten
+
+        r = Subprocess.execute(*command)
+        return nil if r.exit_code != 0
+        return r.stdout.chomp
+      end
     end
   end
 end

plugins/synced_folders/smb/errors.rb

@@ -18,6 +18,10 @@ module VagrantPlugins
         error_key(:powershell_error)
       end
 
+      class PowershellVersion < SMBError
+        error_Key(:powershell_version)
+      end
+
       class WindowsHostRequired < SMBError
         error_key(:windows_host_required)
       end

plugins/synced_folders/smb/scripts/ps_version.ps1

@@ -0,0 +1 @@
+Write-Output $PSVersionTable.PSVersion.Major

plugins/synced_folders/smb/synced_folder.rb

@@ -27,6 +27,15 @@ module VagrantPlugins
           return false
         end
 
+        psv = Vagrant::Util::PowerShell.version.to_i
+        if psv < 3
+          if raise_error
+            raise Errors::PowershellVersion,
+              version: psv.to_s
+          end
+          return false
+        end
+
         true
       end
 

templates/locales/synced_folder_smb.yml

@@ -39,6 +39,10 @@ en:
         Error:
 
         %{stderr}
+      powershell_version: |-
+        PowerShell version 3 or later is required for SMB synced folders
+        to work on Windows. You have version: '%{version}'. Please update
+        your PowerShell installation.
       windows_admin_required: |-
         SMB shared folders require running Vagrant with administrative
         privileges. This is a limitation of Windows, since creating new