Error and exit if SSH command returns non-zero exit status [closes GH-80]

lib/vagrant/ssh.rb

@@ -150,6 +150,10 @@ module Vagrant
       # implementation also reports `:exit_status` to the block if given.
       def exec!(command, &block)
         block ||= Proc.new do |ch, type, data|
+          if type == :exit_status && data != 0
+            raise ActionException.new(:ssh_bad_exit_status, :command => command)
+          end
+
           ch[:result] ||= ""
           ch[:result] << data if [:stdout, :stderr].include?(type)
         end

templates/strings.yml

@@ -134,6 +134,11 @@
   permissions on the following file to 0600 and then try running this command again:
 
   <%= key_path %>
+:ssh_bad_exit_status: |-
+  The following SSH command responded with a non-zero exit status.
+  Vagrant assumes that this means the command failed!
+
+  <%= command %>
 :ssh_unavailable_windows: |-
   `vagrant ssh` isn't available on the Windows platform. The
   vagrant.ppk file is available at