Adding threds to libvirt driver

This patch adds threds to poweroff/poweron/reset methods
to increase the velocity of VMs management.

Change-Id: I03c821d44810cfa76468f1a371b8e46f0ba03311

examples/power_off_on_vm_node.py

@@ -48,6 +48,7 @@ def main():
     logging.info('Pick and power off one of cluster nodes')
     one = nodes.pick()
     one.poweroff()
+    one.poweron()
 
 if __name__ == '__main__':
     logging.basicConfig(format='%(asctime)s %(levelname)s %(message)s',

os_failures/api/error.py

@@ -21,4 +21,4 @@ class OSFError(OSFException):
 
 
 class PowerManagmentError(OSFError):
-    """Base Error for Power Managment API"""
+    """Base Error class for Power Management API"""

os_failures/drivers/libvirt_driver.py

@@ -12,7 +12,8 @@
 # limitations under the License.
 
 import logging
-from xml.dom import minidom
+import threading
+import traceback
 
 import libvirt
 
@@ -20,6 +21,29 @@ from os_failures.api import error
 from os_failures.api import power_management
 
 
+class ThreadsWrapper(object):
+    def __init__(self, target):
+        self.target = target
+        self.threads = []
+        self.errors = []
+
+    def _target(self, **kwargs):
+        try:
+            self.target(**kwargs)
+        except Exception as exc:
+            logging.error(traceback.format_exc())
+            self.errors.append(exc)
+
+    def start_thread(self, **kwargs):
+        thread = threading.Thread(target=self._target, kwargs=kwargs)
+        thread.start()
+        self.threads.append(thread)
+
+    def join_threads(self):
+        for thread in self.threads:
+            thread.join()
+
+
 class LibvirtDriver(power_management.PowerManagement):
     def __init__(self, params):
         self.connection_uri = params['connection_uri']
@@ -37,32 +61,47 @@ class LibvirtDriver(power_management.PowerManagement):
 
     def _find_domain_by_mac_address(self, mac_address):
         for domain in self.conn.listAllDomains():
-            xml = minidom.parseString(domain.XMLDesc())
-            mac_list = xml.getElementsByTagName('mac')
-            for mac in mac_list:
-                if mac_address == mac.getAttribute('address'):
-                    return domain
+            if mac_address in domain.XMLDesc():
+                return domain
 
         raise error.PowerManagmentError(
             'Node with MAC address %s not found!' % mac_address)
 
-    def poweroff(self, mac_addresses_list):
+    def _poweroff(self, mac_address):
+        logging.info('Power off domain with MAC address: %s', mac_address)
+        domain = self._find_domain_by_mac_address(mac_address)
+        domain.destroy()
+        logging.info('Domain (%s) was powered off' % mac_address)
+
+    def _poweron(self, mac_address):
+        logging.info('Power on domain with MAC address: %s', mac_address)
+        domain = self._find_domain_by_mac_address(mac_address)
+        domain.create()
+        logging.info('Domain (%s) was powered on' % mac_address)
+
+    def _reset(self, mac_address):
+        logging.info('Reset domain with MAC address: %s', mac_address)
+        domain = self._find_domain_by_mac_address(mac_address)
+        domain.reset()
+        logging.info('Domain (%s) was reset' % mac_address)
+
+    @staticmethod
+    def _run(target, mac_addresses_list):
+        tw = ThreadsWrapper(target)
         for mac_address in mac_addresses_list:
-            logging.info('Power off domain with MAC address: %s', mac_address)
-            domain = self._find_domain_by_mac_address(mac_address)
-            domain.destroy()
-            logging.info('Domain (%s) was powered off' % mac_address)
+            tw.start_thread(mac_address=mac_address)
+        tw.join_threads()
+
+        if tw.errors:
+            raise error.PowerManagmentError(
+                'There are some errors when working the libvirt driver. '
+                'Please, check logs for more details.')
+
+    def poweroff(self, mac_addresses_list):
+        self._run(self._poweroff, mac_addresses_list)
 
     def poweron(self, mac_addresses_list):
-        for mac_address in mac_addresses_list:
-            logging.info('Power on domain with MAC address: %s', mac_address)
-            domain = self._find_domain_by_mac_address(mac_address)
-            domain.create()
-            logging.info('Domain (%s) was powered on' % mac_address)
+        self._run(self._poweron, mac_addresses_list)
 
     def reset(self, mac_addresses_list):
-        for mac_address in mac_addresses_list:
-            logging.info('Reset domain with MAC address: %s', mac_address)
-            domain = self._find_domain_by_mac_address(mac_address)
-            domain.reset()
-            logging.info('Domain (%s) was reset' % mac_address)
+        self._run(self._reset, mac_addresses_list)