Add implement of restarting processes

This patch adds implementation of restarting processes

Change-Id: I1d88127ec9316c2721f2a1cafc9c7a55b3534875
Implements: bp pythonize-host-and-process-monitor

masakarimonitors/conf/process.py

@@ -18,6 +18,13 @@ monitor_process_opts = [
     cfg.IntOpt('check_interval',
                default=5,
                help='Interval in seconds for checking a process.'),
+    cfg.IntOpt('restart_retries',
+               default=3,
+               help='Number of retries when the failure of restarting a'
+                    ' process.'),
+    cfg.IntOpt('restart_interval',
+               default=5,
+               help='Interval in seconds for restarting a process.'),
     cfg.StrOpt('process_list_path',
                default='/etc/masakarimonitors/process_list.yaml',
                help='The file path of process list.'),

masakarimonitors/processmonitor/process.py

@@ -73,7 +73,7 @@ class ProcessmonitorManager(manager.Manager):
 
                 if len(down_process_list) != 0:
                     # Restart down processes.
-                    pass
+                    self.process_handler.restart_processes(down_process_list)
 
                 # Reload process list and set to the process handler.
                 process_list = self._load_process_list()

masakarimonitors/processmonitor/process_handler/handle_process.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import eventlet
 from oslo_log import log as oslo_logging
 
 import masakarimonitors.conf
@@ -104,3 +105,34 @@ class HandleProcess(object):
                 LOG.error(_LW("Monitoring command raised exception: %s"), e)
 
         return down_process_list
+
+    def restart_processes(self, down_process_list):
+        """Restart processes.
+
+        This method restarts the processes using restart command written in
+        the process list.
+
+        :param down_process_list: down process list object
+        """
+        for down_process in down_process_list:
+            cmd_str = down_process['restart_command']
+
+            LOG.info(
+                _LI("Retart of process with executing command: %s"), cmd_str)
+
+            for retries in range(0, CONF.process.restart_retries + 1):
+
+                # Execute start command.
+                ret = self._execute_cmd(cmd_str, down_process['run_as_root'])
+
+                if ret == 0:
+                    # Succeeded in restarting process.
+                    break
+                else:
+                    # Failed to restart process.
+                    eventlet.greenthread.sleep(CONF.process.restart_interval)
+                    continue
+
+            if retries == CONF.process.restart_retries:
+                # Send a notification.
+                pass

masakarimonitors/tests/unit/processmonitor/process_handler/test_handle_process.py

@@ -36,6 +36,20 @@ MOCK_PROCESS_LIST = [
     },
 ]
 
+MOCK_DOWN_PROCESS_LIST = [
+    {
+        'id': 1,
+        'process_name': 'mock_process_name_A',
+        'start_command': 'mock_start_command',
+        'pre_start_command': 'mock_pre_start_command',
+        'post_start_command': 'mock_post_start_command',
+        'restart_command': 'mock_restart_command',
+        'pre_restart_command': 'mock_pre_restart_command',
+        'post_restart_command': 'mock_post_restart_command',
+        'run_as_root': True
+    },
+]
+
 PS_RESULT = "\n" \
             "UID  PID   PPID C STIME TTY TIME     CMD\n" \
             "root 11187 1    0 18:52 ?   00:00:00 mock_process_name_A\n"
@@ -77,3 +91,19 @@ class TestHandleProcess(testtools.TestCase):
 
         down_process_list = obj.monitor_processes()
         self.assertEqual([], down_process_list)
+
+    @mock.patch.object(utils, 'execute')
+    def test_restart_processes(self,
+                               mock_execute):
+        process_list = MOCK_PROCESS_LIST
+        obj = handle_process.HandleProcess()
+        obj.set_process_list(process_list)
+        down_process_list = MOCK_DOWN_PROCESS_LIST
+
+        mock_execute.return_value = ('test_stdout', '')
+
+        obj.restart_processes(down_process_list)
+
+        mock_execute.assert_called_once_with(
+            MOCK_PROCESS_LIST[0].get('restart_command'),
+            run_as_root=MOCK_DOWN_PROCESS_LIST[0].get('run_as_root'))