SIGHUP, use mpd connection without subcommand

beside being ugly, using "mpc idle" subprocess was making the whole
thing unable to terminate & release HTTP port when closing.

mpc.py

@@ -6,12 +6,12 @@ import logging
 logging.basicConfig(level=logging.INFO,
                     format='%(asctime)s %(message)s',
                     datefmt='%H:%M:%S')
-from subprocess import check_output
+import signal
 
 import gevent
 from gevent.queue import Queue
 from gevent.wsgi import WSGIServer
-
+from mpd import MPDClient
 
 from eventutils import ParentedLet, CeleryTask, Timer
 from task import create as create_continous
@@ -19,12 +19,20 @@ import rpc
 
 
 class MpcWatcher(ParentedLet):
-    def __init__(self, queue):
+    def __init__(self, queue, client=None):
         ParentedLet.__init__(self, queue)
+        if client is None:
+            self.client = MPDClient()
+            # TODO: use config values
+            self.client.connect("localhost", 6600)
+        else:
+            self.client = client  # assume it is already connected
 
     def do_business(self):
         while True:
-            status = check_output(['mpc', 'idle']).decode('utf-8').strip()
+            # status = check_output(['mpc', 'idle']).decode('utf-8').strip()
+            status = self.client.idle()[0]
+            logging.info(status)
             yield ('mpc', status)
 
 
@@ -35,17 +43,18 @@ class Player(gevent.Greenlet):
         self.q = Queue()
 
     def check_playlist(self):
-        out = check_output(['mpc', 'playlist']).decode('utf-8').strip()
-        songs = out.split('\n')
+        mpd_client = MPDClient()
+        # TODO: use config values
+        mpd_client.connect("localhost", 6600)
+        songs = mpd_client.playlist()
         if(len(songs) >= self.min_playlist_length):
-
             return
         logging.info('need to add new songs')
         CeleryTask(create_continous, self.q).start()
         CeleryTask(create_continous, self.q).start()
 
     def _run(self):
-        MpcWatcher(self.q).start()
+        MpcWatcher(self.q, client=None).start()
         Timer(6000, self.q).start()
         http_server = WSGIServer(('', 5000), rpc.create_app(self.q))
         http_server.start()
@@ -65,7 +74,19 @@ class Player(gevent.Greenlet):
             logging.info(str(value))
 
 
+def on_player_crash(*args, **kwargs):
+    print('A crash occurred in "main" greenlet. Aborting...')
+    import sys
+    sys.exit(1)
+
+
 if __name__ == '__main__':
     p = Player()
     p.start()
+    p.link_exception(on_player_crash)
+
+    def sig(*args):
+        print('invoked sig', args)
+        p.q.put('signal', *args)
+    gevent.signal(signal.SIGHUP, sig, signal.SIGHUP)
     gevent.wait()

requirements.txt

@@ -1,3 +1,7 @@
+Flask==0.10.1
+Jinja2==2.7.3
+MarkupSafe==0.23
+Werkzeug==0.9.6
 amqp==1.4.6
 anyjson==0.3.3
 billiard==3.3.0.18
@@ -5,10 +9,12 @@ celery==3.1.16
 eventlet==0.15.2
 gevent==1.0.1
 greenlet==0.4.5
+itsdangerous==0.24
 kombu==3.0.23
 py==1.4.26
 pyinotify==0.9.4
 pytest==2.6.4
+python-mpd2==0.5.3
 pytz==2014.7
 redis==2.10.3
 wsgiref==0.1.2

rpc.py

@@ -5,6 +5,7 @@ rpc = Blueprint('rpc', __name__, url_prefix='/api')
 
 
 def send_to_parent(kind, *args):
+    '''similar to the behaviour of a ParentedLet'''
     if not hasattr(current_app, 'queue'):
         logging.debug('no parent queue; aborting send')
         return