Finish changes to stop an engine

Added a call to stop all react scripts, by passing all known routing
keys to the react_killer function. Then stop the threadpool executor.
Finally, Raise a known exception to stop the watchdog thread. This
will throw an ugly traceback, but will shutdown the engine
gracefully.

Also made minor changes to the example react.json, to change the log
format. Knowing the time a log was printed is useful.

Change-Id: Ibed06f79547312d188feb499f937eb5390d60c3e

entropy/__main__.py

@@ -18,9 +18,7 @@
 import argparse
 import logging
 import os
-import psutil
 import tempfile
-import time
 
 from engine import Engine
 from entropy import utils
@@ -152,13 +150,7 @@ def start_engine(args):
 def stop_engine(args):
     LOG.info("Stopping engine %s", args.name)
     # Grab engine config file, set our engine to disabled
-    pid = utils.disable_engine(args.name, engine_cfg)
-    try:
-        p = psutil.Process(pid)
-        time.sleep(5)
-        p.terminate()
-    except psutil.NoSuchProcess:
-        LOG.exception("No running engine %s", args.name)
+    utils.disable_engine(args.name, engine_cfg)
 
 
 def parse():

entropy/engine.py

@@ -73,8 +73,11 @@ class Engine(object):
         self.futures = []
         self.run_queue = collections.deque()
         # Private variables
-        self._watchdog_event_fn = {self.repair_cfg: self.repair_modified,
-                                   self.engine_cfg: self.engine_disabled}
+        self._watchdog_event_fn = {
+            self.repair_cfg: self.repair_modified,
+            self.engine_cfg: self.engine_disabled,
+            self.audit_cfg: self.audit_modified,
+        }
         # Private variables to keep track of repair scripts.
         self._repairs = []
         self._known_routing_keys = collections.defaultdict(list)
@@ -126,6 +129,7 @@ class Engine(object):
         self.start_scheduler()
 
     def start_scheduler(self):
+        # Start serializer
         if not self._serializer:
             self._serializer = self.executor.submit(self.start_serializer)
             self.futures.append(self._serializer)
@@ -137,6 +141,7 @@ class Engine(object):
         self.futures.extend(self.start_react_scripts(
             self._get_react_scripts()))
 
+        # Start scheduler
         self._scheduler = self.executor.submit(self.schedule)
         self.futures.append(self._scheduler)
         self._scheduler.add_done_callback(
@@ -257,15 +262,32 @@ class Engine(object):
 
     def stop_engine(self):
         LOG.info("Stopping engine %s", self.name)
-        # Set state to stop, which will stop serializers
+        # Set state to stop, which will stop serializer, and scheduler
         self._state = states.DISABLED
         # Clear run queue
         LOG.info("Clearing audit run queue for %s", self.name)
         self.run_queue.clear()
-        # Stop all repairs - not yet implemented
+
+        # Stop all repairs
+        LOG.info("Stopping all repairs for %s", self.name)
+        repairs_to_stop = self._known_routing_keys.keys()
+        self.stop_react_scripts(repairs_to_stop)
+
+        # Stop the executor - this is a blocking call.
+        LOG.info("Shutting down executor for %s", self.name)
+        self.executor.shutdown()
+
         # Stop watchdog monitoring
         LOG.info("Stopping watchdog for %s", self.name)
-        self._watchdog_thread.stop()
+        # NOTE(praneshp): Till the watchdog authors respond with the right way
+        # to stop watchdog, we'll raise something from here. That will stop
+        # the watchdog thread, go back to the join() in start_scheduler(), and
+        # quit the program
+        raise exceptions.EngineStoppedException(
+            'Fake exception to kill watchdog thread')
+
+    def audit_modified(self):
+        return NotImplemented
 
     def repair_modified(self):
         LOG.info('Repair configuration changed')
@@ -289,7 +311,7 @@ class Engine(object):
     def start_watchdog(self):
         LOG.debug('Watchdog mapping is: ', self._watchdog_event_fn)
         dirs_to_watch = [utils.get_filename_and_path(x)[0] for x in
-                         self.engine_cfg, self.repair_cfg]
+                         self.engine_cfg, self.repair_cfg, self.audit_cfg]
         return utils.watch_dir_for_change(dirs_to_watch,
                                           self._watchdog_event_fn)
 
@@ -323,11 +345,9 @@ class Engine(object):
 
     def stop_react_scripts(self, repairs_to_stop):
         # current react scripts
-        LOG.info("Currently running react scripts: %s", self._repairs)
         for repair in repairs_to_stop:
             self.stop_react(repair)
         # react scripts at the end
-        LOG.info("Currently running react scripts: %s", self._repairs)
 
     def stop_react(self, repair):
         LOG.info("Stopping react script %s", repair)

entropy/examples/repair/react.json

@@ -9,5 +9,5 @@
     "mq_password": "guest",
     "routing_key": "demo",
     "log_file": "/home/praneshp/code/entropy/entropy/examples/logs/demo.log",
-    "log_format": "%(filename)s %(lineno)s %(message)s"
+    "log_format": "%(asctime)s %(lineno)s %(message)s"
 }

entropy/utils.py

@@ -110,6 +110,7 @@ def watch_dir_for_change(dirs_to_watch, event_fn):
     observer = Observer()
     for directory in dirs_to_watch:
         observer.schedule(event_handler, path=directory)
+    observer.setDaemon(True)
     observer.start()
     return observer