hosts/linux: sudo to copy back to exports [hashicorpGH-5957]

CHANGELOG.md

@@ -7,6 +7,7 @@ BUG FIXES:
   - guests/redhat: systemd detection should happen on guest [GH-5948]
   - guests/ubuntu: setting hostname fixed in 12.04 [GH-5937]
   - hosts/linux: NFS can be configured without `$TMP` set on the host [GH-5954]
+  - hosts/linux: NFS will sudo copying back to `/etc/exports` [GH-5957]
   - providers/virtulabox: remove UNC path conversion on Windows since it
       caused mounting regressions [GH-5933]
   - provisioners/puppet: Windows Puppet 4 paths work correctly [GH-5967]

plugins/hosts/linux/cap/nfs.rb

@@ -103,7 +103,7 @@ def self.nfs_cleanup(id)
           # Use sed to just strip out the block of code which was inserted
           # by Vagrant
           tmp = ENV["TMPDIR"] || ENV["TMP"] || "/tmp"
-          system("cp /etc/exports '#{tmp}' && #{sudo_command}sed -r -e '\\\x01^# VAGRANT-BEGIN:( #{user})? #{id}\x01,\\\x01^# VAGRANT-END:( #{user})? #{id}\x01 d' -ibak '#{tmp}/exports' ; cp '#{tmp}/exports' /etc/exports")
+          system("cp /etc/exports '#{tmp}' && #{sudo_command}sed -r -e '\\\x01^# VAGRANT-BEGIN:( #{user})? #{id}\x01,\\\x01^# VAGRANT-END:( #{user})? #{id}\x01 d' -ibak '#{tmp}/exports' ; #{sudo_command}cp '#{tmp}/exports' /etc/exports")
         end
 
         def self.nfs_opts_setup(folders)