Fix node.py: try_shutdown and cleanup (#144)

Author: demonolock

Diff for: testgres/node.py

@@ -334,37 +334,38 @@ def _try_shutdown(self, max_attempts, with_force=False):
         attempts = 0
         node_pid = self.pid
 
-        # try stopping server N times
-        while attempts < max_attempts:
-            try:
-                self.stop()
-                break    # OK
-            except ExecUtilException:
-                pass    # one more time
-            except Exception:
-                eprint('cannot stop node {}'.format(self.name))
-                break
-
-            attempts += 1
-
-        # If force stopping is enabled and PID is valid
-        if with_force and node_pid != 0:
-            # If we couldn't stop the node
-            p_status_output = self.os_ops.exec_command(cmd=f'ps -p {node_pid}', shell=True).decode('utf-8')
-            if self.status() != NodeStatus.Stopped and p_status_output and str(node_pid) in p_status_output:
+        if node_pid > 0:
+            # try stopping server N times
+            while attempts < max_attempts:
                 try:
-                    eprint(f'Force stopping node {self.name} with PID {node_pid}')
-                    self.os_ops.kill(node_pid, signal.SIGKILL, expect_error=False)
+                    self.stop()
+                    break    # OK
+                except ExecUtilException:
+                    pass    # one more time
                 except Exception:
-                    # The node has already stopped
-                    pass
-
-            # Check that node stopped - print only column pid without headers
-            p_status_output = self.os_ops.exec_command(f'ps -o pid= -p {node_pid}', shell=True, ignore_errors=True).decode('utf-8')
-            if p_status_output and str(node_pid) in p_status_output:
-                eprint(f'Failed to stop node {self.name}.')
-            else:
-                eprint(f'Node {self.name} has been stopped successfully.')
+                    eprint('cannot stop node {}'.format(self.name))
+                    break
+
+                attempts += 1
+
+            # If force stopping is enabled and PID is valid
+            if with_force and node_pid != 0:
+                # If we couldn't stop the node
+                p_status_output = self.os_ops.exec_command(cmd=f'ps -p {node_pid}', shell=True).decode('utf-8')
+                if self.status() != NodeStatus.Stopped and p_status_output and str(node_pid) in p_status_output:
+                    try:
+                        eprint(f'Force stopping node {self.name} with PID {node_pid}')
+                        self.os_ops.kill(node_pid, signal.SIGKILL, expect_error=False)
+                    except Exception:
+                        # The node has already stopped
+                        pass
+
+                # Check that node stopped - print only column pid without headers
+                p_status_output = self.os_ops.exec_command(f'ps -o pid= -p {node_pid}', shell=True, ignore_errors=True).decode('utf-8')
+                if p_status_output and str(node_pid) in p_status_output:
+                    eprint(f'Failed to stop node {self.name}.')
+                else:
+                    eprint(f'Node {self.name} has been stopped successfully.')
 
     def _assign_master(self, master):
         """NOTE: this is a private method!"""