set hostname on archlinux [closes GH-439]

Signed-off-by: Dave Simons <dave@inuits.be>

lib/vagrant/systems.rb

@@ -10,3 +10,4 @@ require 'vagrant/systems/gentoo'
 require 'vagrant/systems/redhat'
 require 'vagrant/systems/suse'
 require 'vagrant/systems/ubuntu'
+require 'vagrant/systems/arch'

lib/vagrant/systems/arch.rb

@@ -0,0 +1,16 @@
+module Vagrant
+  module Systems
+    class Arch < Linux
+      def change_host_name(name)
+        vm.ssh.execute do |ssh|
+          # Only do this if the hostname is not already set
+          if !ssh.test?("sudo hostname | grep '#{name}'")
+            ssh.exec!("sudo sed -i 's/\\(HOSTNAME=\\).*/\\1#{name}/' /etc/rc.conf")
+            ssh.exec!("sudo hostname #{name}")
+            ssh.exec!("sudo sed -i 's@^\\(127[.]0[.]0[.]1[[:space:]]\\+\\)@\\1#{name} @' /etc/hosts")
+          end
+        end
+      end
+    end
+  end
+end

lib/vagrant/systems/linux.rb

@@ -14,6 +14,7 @@ module Vagrant
           return :gentoo if ssh.test?("cat /etc/gentoo-release")
           return :redhat if ssh.test?("cat /etc/redhat-release")
           return :suse if ssh.test?("cat /etc/SuSE-release")
+          return :arch if ssh.test?("cat /etc/arch-release")
         end
 
         # Can't detect the distro, assume vanilla linux

lib/vagrant/vm.rb

@@ -66,7 +66,8 @@ module Vagrant
           :redhat  => Systems::Redhat,
           :suse    => Systems::Suse,
           :linux   => Systems::Linux,
-          :solaris => Systems::Solaris
+          :solaris => Systems::Solaris,
+          :arch    => Systems::Arch
         }
 
         raise Errors::VMSystemError, :_key => :unknown_type, :system => system.to_s if !mapping.has_key?(system)