[libvirt|compute] Allow volumes to be cloned at the disk level

lib/fog/libvirt/compute.rb

@@ -38,6 +38,7 @@ module Fog
       request :list_volumes
       request :volume_action
       request :create_volume
+      request :clone_volume
       request :list_networks
       request :destroy_network
       request :list_interfaces

lib/fog/libvirt/models/compute/volume.rb

@@ -62,6 +62,17 @@ module Fog
           new_volume.reload
         end
 
+        def clone_volume(new_name)
+          requires :pool_name
+
+          new_volume      = self.dup
+          new_volume.key  = nil
+          new_volume.name = new_name
+          new_volume.path = service.clone_volume(pool_name, new_volume.to_xml, self.name).path
+
+          new_volume.reload
+        end
+
         private
 
         def image_suffix

lib/fog/libvirt/requests/compute/clone_volume.rb

@@ -0,0 +1,18 @@
+module Fog
+  module Compute
+    class Libvirt
+      class Real
+        def clone_volume (pool_name, xml, name)
+          vol = client.lookup_storage_pool_by_name(pool_name).lookup_volume_by_name(name)
+          client.lookup_storage_pool_by_name(pool_name).create_vol_xml_from(xml, vol)
+        end
+      end
+
+      class Mock
+        def clone_volume(pool_name, xml, name)
+          Fog::Compute::Libvirt::Volume.new({:pool_name => pool_name, :xml => xml})
+        end
+      end
+    end
+  end
+end

tests/libvirt/models/compute/volume_tests.rb

@@ -27,4 +27,12 @@ Shindo.tests('Fog::Compute[:libvirt] | volume model', ['libvirt']) do
     test('be a kind of Fog::Compute::Libvirt::Volume') { volume.kind_of? Fog::Compute::Libvirt::Volume }
   end
 
+  tests('Cloning volumes should') do
+    test('respond to clone_volume') { volume.respond_to? :clone_volume }
+    new_vol = volume.clone_volume('new_vol')
+    # We'd like to test that the :name attr has changed, but it seems that's
+    # not possible, so we can at least check the new_vol xml exists properly
+    test('succeed') { volume.xml == new_vol.xml }
+  end
+
 end