Added test for getting non zero exit code with no stdout. Fixed issue where lack of stdout would cause pssh client to hang

Author: Dan

pssh.py

@@ -246,7 +246,8 @@ def exec_command(self, command, sudo=False, user=None, **kwargs):
         logger.debug("Running command %s on %s", command, self.host)
         channel.exec_command(command, **kwargs)
         logger.debug("Command started")
-        while not (channel.recv_ready() or channel.closed):
+        while not (channel.recv_ready() or channel.closed or
+                   channel.exit_status_ready()):
             gevent.sleep(.2)
         return channel, self.host, stdout, stderr
 

tests/test_pssh_client.py

@@ -71,10 +71,22 @@ def test_pssh_client_exec_command(self):
         client.pool.join()
         output = client.get_stdout(cmd)
         expected = {'127.0.0.1' : {'exit_code' : 0}}
-        self.assertEqual(output, expected,
+        self.assertEqual(expected, output,
                          msg="Got unexpected command output - %s" % (output,))
         self.assertTrue(output['127.0.0.1']['exit_code'] == 0)
 
+    def test_pssh_client_no_stdout_non_zero_exit_code(self):
+        client = ParallelSSHClient(['127.0.0.1'], port=self.listen_port,
+                                   pkey=self.user_key)
+        output = client.run_command('exit 1')
+        expected_exit_code = 1
+        exit_code = output['127.0.0.1']['exit_code']
+        client.pool.join()
+        self.assertEqual(expected_exit_code, exit_code,
+                         msg="Got unexpected exit code - %s, expected %s" %
+                         (exit_code,
+                          expected_exit_code,))
+
     def test_pssh_client_exec_command_get_buffers(self):
         client = ParallelSSHClient(['127.0.0.1'], port=self.listen_port,
                                    pkey=self.user_key)