Begin working on the #guest method for Machine instances

lib/vagrant/errors.rb

@@ -226,6 +226,10 @@ module Vagrant
       error_key(:port_collision_resume)
     end
 
+    class MachineGuestNotReady < VagrantError
+      error_key(:machine_guest_not_ready)
+    end
+
     class MultiVMEnvironmentRequired < VagrantError
       status_code(5)
       error_key(:multi_vm_required)

lib/vagrant/machine.rb

@@ -123,6 +123,16 @@ module Vagrant
       @communicator
     end
 
+    # Returns a guest implementation for this machine. The guest implementation
+    # knows how to do guest-OS specific tasks, such as configuring networks,
+    # mounting folders, etc.
+    #
+    # @return [Object]
+    def guest
+      raise Errors::MachineGuestNotReady if !communicator.ready?
+      # XXX: Todo
+    end
+
     # This sets the unique ID associated with this machine. This will
     # persist this ID so that in the future Vagrant will be able to find
     # this machine again. The unique ID must be absolutely unique to the

templates/locales/en.yml

@@ -85,6 +85,10 @@ en:
         You specified: %{home_path}
       interrupted: |-
         Vagrant exited after cleanup due to external interrupt.
+      machine_guest_not_ready: |-
+        Guest-specific operations were attempted on a machine that is not
+        ready for guest communication. This should not happen and a bug
+        should be reported.
       multi_vm_required: |-
         A multi-vm environment is required for name specification to this command.
       multi_vm_target_required: |-

test/unit/vagrant/machine_test.rb

@@ -191,6 +191,25 @@ describe Vagrant::Machine do
     end
   end
 
+  describe "guest implementation" do
+    let(:communicator) do
+      result = double("communicator")
+      result.stub(:ready?).and_return(true)
+      result
+    end
+
+    before(:each) do
+      instance.stub(:communicator).and_return(communicator)
+    end
+
+    it "should raise an exception if communication is not ready" do
+      communicator.should_receive(:ready?).and_return(false)
+
+      expect { instance.guest }.
+        to raise_error(Vagrant::Errors::MachineGuestNotReady)
+    end
+  end
+
   describe "setting the ID" do
     it "should not have an ID by default" do
       instance.id.should be_nil