Plug machine#uid methods into remote go backend

internal/core/machine.go

@@ -2,6 +2,7 @@ package core
 
 import (
 	"fmt"
+	"os/user"
 	"reflect"
 	"sort"
 
@@ -38,6 +39,15 @@ func (m *Machine) ID() (id string, err error) {
 // SetID implements core.Machine
 func (m *Machine) SetID(value string) (err error) {
 	m.machine.Id = value
+
+	// Also set uid
+	user, err := user.Current()
+	if err != nil {
+		return err
+	}
+	m.machine.Uid = user.Uid
+
+	// Persist changes
 	if value == "" {
 		m.target.Record = nil
 		err = m.Destroy()

lib/vagrant/machine/remote.rb

@@ -237,10 +237,7 @@ module Vagrant
       end
 
       def uid
-        path = uid_file
-        return nil if !path
-        return nil if !path.file?
-        return uid_file.read.chomp
+        client.uid
       end
 
       def with_ui(ui)
@@ -255,11 +252,6 @@ module Vagrant
         end
       end
 
-      def uid_file
-        return nil if !@data_dir
-        @data_dir.join("creator_uid")
-      end
-
       def check_cwd
         desired_encoding = @env.root_path.to_s.encoding
         vagrant_cwd_filepath = @data_dir.join('vagrant_cwd')

plugins/commands/serve/client/target/machine.rb

@@ -118,7 +118,9 @@ module VagrantPlugins
 
           # @return [Integer] user ID that owns machine
           def uid
-            client.uid(Empty.new).user_id
+            user_id = client.uid(Empty.new).user_id
+            return nil if user_id == ""
+            return user_id
           end
 
           def _cleaned_folder_hash(folder)