Use explicit removal of disk volumes if CDROM attached

Use the more conservative path if either disks or cdroms present for
the domain configuration.

Domain destroy including volumes will attempt to delete any attached
CDROM images as they are registered as volumes. Resulting in the
following error message:

    fog-libvirt-0.0.3/lib/fog/libvirt/requests/compute/volume_action.rb:6:in
    `delete': Call to virStorageVol Delete failed: cannot unlink file
    '<path-to-iso>': Success (Libvirt::Error)

Co-Authored-By: Darragh Bailey <dbailey@hpe.com>
Change-Id: Ia497aef0e871de88e65c46afe071b2618fda5588

lib/vagrant-libvirt/action/destroy_domain.rb

@@ -35,8 +35,10 @@ module VagrantPlugins
 
           domain = env[:machine].provider.driver.connection.servers.get(env[:machine].id.to_s)
 
-          if env[:machine].provider_config.disks.empty?
-            # if using default configuration of disks
+          if env[:machine].provider_config.disks.empty? and
+              env[:machine].provider_config.cdroms.empty?
+            # if using default configuration of disks and cdroms
+            # cdroms are consider volumes, but cannot be destroyed
             domain.destroy(destroy_volumes: true)
           else
             domain.destroy(destroy_volumes: false)

spec/unit/action/destroy_domain_spec.rb

@@ -70,6 +70,27 @@ describe VagrantPlugins::ProviderLibvirt::Action::DestroyDomain do
           expect(subject.call(env)).to be_nil
         end
       end
+
+      context "when has CDROMs attached" do
+        let(:vagrantfile) { <<-EOF
+          Vagrant.configure('2') do |config|
+            config.vm.define :test
+            config.vm.provider :libvirt do |libvirt|
+              libvirt.storage :file, :device => :cdrom
+            end
+          end
+          EOF
+        }
+
+        it "uses explicit removal of disks" do
+          allow(libvirt_domain).to receive(:name).and_return("test")
+          allow(domain).to receive(:volumes).and_return([root_disk])
+
+          expect(domain).to_not receive(:destroy).with(:destroy_volumes => true)
+          expect(root_disk).to receive(:destroy)  # root disk remove
+          expect(subject.call(env)).to be_nil
+        end
+      end
     end
   end
 end