Document how to use libvirt driver

Change-Id: I5cba6ee970b64f4a63317169c3ab90613fbe0bb6
Closes-Bug: #1836736

README.rst

@@ -29,10 +29,10 @@ Regular installation::
 
     pip install os-faults
 
-The library contains optional libvirt driver, if you plan to use it,
+The library contains optional libvirt driver [https://pypi.org/project/libvirt-python/], if you plan to use it,
 please use the following command to install os-faults with extra dependencies::
 
-    pip install os-faults[libvirt]
+    pip install os-faults libvirt-python
 
 
 Configuration

os_faults/api/power_management.py

@@ -24,7 +24,7 @@ from os_faults import utils
 class PowerDriver(base_driver.BaseDriver):
 
     @abc.abstractmethod
-    def supports(host):
+    def supports(self, host):
         """Returns True if host is supported by the power driver"""
 
     @abc.abstractmethod

os_faults/drivers/nodes/node_list.py

@@ -77,6 +77,7 @@ class NodeListDiscover(node_discover.NodeDiscover):
       MAC address is used for libvirt driver.
     - **fqdn** - FQDN of the node (optional).
       FQDN is used for filtering only.
+    - **libvirt_name** - Libvirt domain name (optional).
     - **auth** - SSH related parameters (optional):
         - **username** - SSH username (optional)
         - **password** - SSH password (optional)

os_faults/drivers/power/libvirt.py

@@ -37,6 +37,9 @@ class LibvirtDriver(power_management.PowerDriver):
 
     - **connection_uri** - libvirt uri
 
+    Note that Libvirt domain name should be specified as node attribute.
+    Refer to node discover (node_list driver) for details.
+
     """
 
     NAME = 'libvirt'
@@ -88,9 +91,9 @@ class LibvirtDriver(power_management.PowerDriver):
 
     def poweroff(self, host):
         domain = self._find_domain_by_host(host)
-        LOG.debug('Power off domain with name: %s', host.mac)
+        LOG.debug('Power off domain with name: %s', domain.name())
         domain.destroy()
-        LOG.info('Domain powered off: %s', host.mac)
+        LOG.info('Domain powered off: %s', domain.name())
 
     def poweron(self, host):
         domain = self._find_domain_by_host(host)