Private networking: Create bridge if it is missing

lib/vagrant-lxc/driver.rb

@@ -134,6 +134,20 @@ module Vagrant
           ip += '/24'
         end
 
+        if ! bridge_exists?(bridge_name)
+          if not bridge_ip
+            raise "Bridge is missing and no IP was specified!"
+          end
+
+          @logger.info "Creating the bridge #{bridge_name}"
+          cmd = [
+            'brctl',
+            'addbr',
+            bridge_name
+          ]
+          @sudo_wrapper.run(*cmd)
+        end
+
         if ! bridge_has_an_ip?(bridge_name)
           if not bridge_ip
             raise "Bridge has no IP and none was specified!"
@@ -148,6 +162,7 @@ module Vagrant
             bridge_name
           ]
           @sudo_wrapper.run(*cmd)
+          @sudo_wrapper.run('ifconfig', bridge_name, 'up')
         end
 
         cmd = [

templates/sudoers.rb.erb

@@ -106,8 +106,8 @@ Whitelist.add '<%= cmd_paths['tar'] %>', '--numeric-owner', '-cvzf', %r{/tmp/.*/
 Whitelist.add '<%= cmd_paths['chown'] %>', /\A\d+:\d+\z/, %r{\A/tmp/.*/rootfs\.tar\.gz\z}
 # - Private network script and commands
 Whitelist.add '<%= cmd_paths['ip'] %>', 'addr', 'add', /(\d+|\.)+\/24/, 'dev', /.+/
-Whitelist.add '<%= cmd_paths['ifconfig'] %>', /.+/, 'down'
+Whitelist.add '<%= cmd_paths['ifconfig'] %>', /.+/, /(up|down)/
-Whitelist.add '<%= cmd_paths['brctl'] %>', 'delbr', /.+/
+Whitelist.add '<%= cmd_paths['brctl'] %>', /(addbr|delbr)/, /.+/
 Whitelist.add_regex %r{<%= pipework_regex %>}, '**'
 
 ##