libvirt: Fix unsupported 'parallels' virt type

Nova supports the parallels virt type but the type is not accepted by
ceilometer. This fixes it and allows users to use metric gathering via
libvirt API when parallels virt type is used.

Change-Id: I683df5d4e301cec6eabb0fd17d3b5240ebd09149

ceilometer/compute/virt/libvirt/utils.py

@@ -30,7 +30,7 @@ LOG = logging.getLogger(__name__)
 OPTS = [
     cfg.StrOpt('libvirt_type',
                default='kvm',
-               choices=['kvm', 'lxc', 'qemu', 'uml'],
+               choices=['kvm', 'lxc', 'qemu', 'parallels', 'uml'],
                help='Libvirt domain type.'),
     cfg.StrOpt('libvirt_uri',
                default='',
@@ -38,7 +38,10 @@ OPTS = [
                     '(which is dependent on libvirt_type).'),
 ]
 
-LIBVIRT_PER_TYPE_URIS = dict(uml='uml:///system', lxc='lxc:///')
+LIBVIRT_PER_TYPE_URIS = dict(
+    uml='uml:///system',
+    parallels='parallels:///system',
+    lxc='lxc:///')
 
 
 # We don't use the libvirt constants in case of libvirt is not available

releasenotes/notes/parallels-virt_type-ee29c4802fdf5c8e.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    The ``[DEFAULT] virt_type`` option now supports ``parallels``.