Implement get_host_uptime for powervm driver

This patch implements the get_host_uptime method for the powervm driver
by calling the sysstat command on the backing hypervisor and returning
the parsed results.

Fixes bug 1191785

Change-Id: I67aaf6a5f5eb6b3a411ca9a0284d9a3016dd2947

nova/tests/virt/powervm/test_powervm.py

@@ -173,7 +173,8 @@ class FakeBlockAdapter(powervm_blockdev.PowerVMLocalVolumeAdapter):
 
 
 def fake_get_powervm_operator():
-    return FakeIVMOperator(None)
+    return FakeIVMOperator(common.Connection('fake_host', 'fake_user',
+                                             'fake_password'))
 
 
 def create_instance(testcase):
@@ -618,6 +619,25 @@ class PowerVMDriverTestCase(test.TestCase):
         self.assertEquals(host_stats['supported_instances'][0][1], "powervm")
         self.assertEquals(host_stats['supported_instances'][0][2], "hvm")
 
+    def test_get_host_uptime(self):
+        """
+        Tests that the get_host_uptime method issues the proper sysstat command
+        and parses the output correctly.
+        """
+        exp_cmd = "ioscli sysstat -short fake_user"
+        output = [("02:54PM  up 24 days,  5:41, 1 user, "
+                   "load average: 0.06, 0.03, 0.02")]
+
+        fake_op = self.powervm_connection._powervm
+        self.mox.StubOutWithMock(fake_op._operator, 'run_vios_command')
+        fake_op._operator.run_vios_command(exp_cmd).AndReturn(output)
+
+        self.mox.ReplayAll()
+
+        # the host parameter isn't used so we just pass None
+        uptime = self.powervm_connection.get_host_uptime(None)
+        self.assertEquals("02:54PM  up 24 days  5:41", uptime)
+
 
 class PowerVMDriverLparTestCase(test.TestCase):
     """Unit tests for PowerVM connection calls."""

nova/virt/powervm/command.py

@@ -1,6 +1,6 @@
 # vim: tabstop=4 shiftwidth=4 softtabstop=4
 
-# Copyright 2012 IBM Corp.
+# Copyright 2013 IBM Corp.
 #
 #    Licensed under the Apache License, Version 2.0 (the "License"); you may
 #    not use this file except in compliance with the License. You may obtain
@@ -68,6 +68,15 @@ class BaseCommand(object):
     def chsyscfg(self, args=''):
         return 'chsyscfg %s' % args
 
+    def sysstat(self, args=''):
+        """
+        Returns a string of the formatted sysstat command to run.
+        Typically this command should be run with the -short option
+        and a User operand should be provided to narrow the results.
+        :returns: string - formatted sysstat command
+        """
+        return 'sysstat %s' % args
+
 
 class IVMCommand(BaseCommand):
 
@@ -97,3 +106,6 @@ class IVMCommand(BaseCommand):
 
     def hostname(self, args=''):
         return 'ioscli ' + BaseCommand.hostname(self, args=args)
+
+    def sysstat(self, args=''):
+        return 'ioscli ' + BaseCommand.sysstat(self, args=args)

nova/virt/powervm/driver.py

@@ -90,6 +90,10 @@ class PowerVMDriver(driver.ComputeDriver):
         """Return currently known host stats."""
         return self._powervm.get_host_stats(refresh=refresh)
 
+    def get_host_uptime(self, host):
+        """Returns the result of calling "uptime" on the target host."""
+        return self._powervm.get_host_uptime(host)
+
     def plug_vifs(self, instance, network_info):
         pass
 

nova/virt/powervm/operator.py

@@ -169,6 +169,10 @@ class PowerVMOperator(object):
 
         self._host_stats = data
 
+    def get_host_uptime(self, host):
+        """Returns the result of calling "uptime" on the target host."""
+        return self._operator.get_host_uptime(host)
+
     def spawn(self, context, instance, image_id, network_info):
         def _create_image(context, instance, image_id):
             """Fetch image from glance and copy it to the remote system."""
@@ -626,6 +630,19 @@ class BaseOperator(object):
         return {'total_mem': int(total_mem),
                 'avail_mem': int(avail_mem)}
 
+    def get_host_uptime(self, host):
+        """
+        Get host uptime.
+        :returns: string - amount of time since last system startup
+        """
+        # The output of the command is like this:
+        # "02:54PM  up 24 days,  5:41, 1 user, load average: 0.06, 0.03, 0.02"
+        cmd = self.command.sysstat('-short %s' % self.connection_data.username)
+        output = self.run_vios_command(cmd)
+        # parse the sysstat output so we just return the uptime
+        system_time, uptime = output[0].split(',')[0:2]
+        return system_time + uptime
+
     def get_cpu_info(self):
         """Get CPU info.