qa/ceph-volume: allow executing python pyloads using python3

Signed-off-by: Rishabh Dave <ridave@redhat.com>

qa/tasks/cephfs/mount.py

@@ -144,13 +144,14 @@ def create_destroy(self):
             'sudo', 'rm', '-f', os.path.join(self.mountpoint, filename)
         ])
 
-    def _run_python(self, pyscript):
-        return self.client_remote.run(args=[
-            'sudo', 'adjust-ulimits', 'daemon-helper', 'kill', 'python', '-c', pyscript
-        ], wait=False, stdin=run.PIPE, stdout=StringIO())
-
-    def run_python(self, pyscript):
-        p = self._run_python(pyscript)
+    def _run_python(self, pyscript, py_version='python'):
+        return self.client_remote.run(
+               args=['sudo', 'adjust-ulimits', 'daemon-helper', 'kill',
+                     py_version, '-c', pyscript], wait=False, stdin=run.PIPE,
+               stdout=StringIO())
+
+    def run_python(self, pyscript, py_version='python'):
+        p = self._run_python(pyscript, py_version)
         p.wait()
         return p.stdout.getvalue().strip()
 

qa/tasks/cephfs/test_volume_client.py

@@ -14,6 +14,7 @@ class TestVolumeClient(CephFSTestCase):
     # One for looking at the global filesystem, one for being
     # the VolumeClient, two for mounting the created shares
     CLIENTS_REQUIRED = 4
+    py_version = 'python'
 
     def _volume_client_python(self, client, script, vol_prefix=None, ns_prefix=None):
         # Can't dedent this *and* the script we pass in, because they might have different
@@ -32,7 +33,9 @@ def _volume_client_python(self, client, script, vol_prefix=None, ns_prefix=None)
 vc.connect()
 {payload}
 vc.disconnect()
-        """.format(payload=script, conf_path=client.config_path, vol_prefix=vol_prefix, ns_prefix=ns_prefix))
+        """.format(payload=script, conf_path=client.config_path,
+                   vol_prefix=vol_prefix, ns_prefix=ns_prefix),
+        self.py_version)
 
     def _sudo_write_file(self, remote, path, data):
         """

qa/tasks/vstart_runner.py

@@ -540,15 +540,13 @@ def list_connections():
 
         self.gather_mount_info()
 
-    def _run_python(self, pyscript):
+    def _run_python(self, pyscript, py_version='python'):
         """
         Override this to remove the daemon-helper prefix that is used otherwise
         to make the process killable.
         """
-        return self.client_remote.run(args=[
-            'python', '-c', pyscript
-        ], wait=False)
-
+        return self.client_remote.run(args=[py_version, '-c', pyscript],
+                                      wait=False)
 
 class LocalCephManager(CephManager):
     def __init__(self):