Add kill method to PsProcess

Change-Id: Id9a10672086dac8bc23b54ed496161aa6989e4d2

tobiko/shell/sh/_ps.py

@@ -67,6 +67,15 @@ class PsProcessBase:
             LOG.error(str(ex))
             return None
 
+    def kill(self, signal: int = None, **execute_params):
+        command_line = _command.shell_command("kill")
+        if signal is not None:
+            command_line += f"-s {signal}"
+        command_line += str(self.pid)
+        _execute.execute(command_line,
+                         ssh_client=self.ssh_client,
+                         **execute_params)
+
 
 class PsProcessTuple(typing.NamedTuple):
     """Process listed by ps command

tobiko/tests/functional/openstack/test_topology.py

@@ -117,8 +117,7 @@ class OpenStackTopologyTest(testtools.TestCase):
         self.assertIs(node.ssh_client, processes.unique.ssh_client)
 
         # Process isn't listed after kill
-        sh.execute(f"kill -9 {processes.unique.pid}",
-                   ssh_client=node.ssh_client)
+        processes.unique.kill()
         for attempt in tobiko.retry(timeout=30., interval=5.):
             processes = topology.list_nodes_processes(
                 command_line=command_line,