Merge ~newell-jensen/maas:lp1777742 into maas:master

[Newell Jensen]

LP: #1777742 -- Add nvram flag to virsh undefine command so that when the virsh domain is undefined it will remove the nvram file, if it is inactive.

[Andres Rodriguez (andreserl)]

lgtm!

review: Approve

diff --git a/src/provisioningserver/drivers/pod/tests/test_virsh.py b/src/provisioningserver/drivers/pod/tests/test_virsh.py
index 60bf860..a46f0a0 100644
--- a/src/provisioningserver/drivers/pod/tests/test_virsh.py
+++ b/src/provisioningserver/drivers/pod/tests/test_virsh.py
@@ -1581,9 +1581,8 @@ class TestVirshSSH(MAASTestCase):
         self.assertThat(mock_run, MockCallsMatch(
             call(['destroy', domain]),
             call([
-                'undefine', domain,
-                '--remove-all-storage',
-                '--managed-save'])))
+                'undefine', domain, '--remove-all-storage',
+                '--managed-save', '--nvram'])))
 
 
 class TestVirsh(MAASTestCase):
diff --git a/src/provisioningserver/drivers/pod/virsh.py b/src/provisioningserver/drivers/pod/virsh.py
index aa88121..a19e0aa 100644
--- a/src/provisioningserver/drivers/pod/virsh.py
+++ b/src/provisioningserver/drivers/pod/virsh.py
@@ -986,7 +986,8 @@ class VirshSSH(pexpect.spawn):
         # Removed the --delete-snapshots flag to workaround the volumes not
         # being deleted.  See the bug for more details.
         self.run([
-            'undefine', domain, '--remove-all-storage', '--managed-save'])
+            'undefine', domain, '--remove-all-storage',
+            '--managed-save', '--nvram'])
 
 
 class VirshPodDriver(PodDriver):