proper logging, add signal handler for graceful termination

streams.py

@@ -1,6 +1,7 @@
 import socket
 import time
 import re
+import logging
 from select import select
 
 
@@ -27,10 +28,10 @@ class Base:
     select_write = {}
 
     def close(self):
-        print('CLOSE BASE')
+        logging.info('CLOSE BASE')
 
     def finish_events(self, *args):
-        print('FINISH BASE')
+        logging.info('FINISH BASE')
 
 
 def short_hostname(host):
@@ -74,7 +75,7 @@ class Stream(Base):
             self.connect()
             self.init(**kwds)
         except Exception as e:
-            print('FAIL', self.uri, repr(e))
+            logging.info('failled connecting %s %r', self.uri, e)
             raise
 
     def connect(self):
@@ -84,7 +85,7 @@ class Stream(Base):
         host, _, port = self.uri.partition(':')
         # try to convert uri to host name
         self.uri = self.tags['stream'] = f'{short_hostname(host)}:{port}'
-        print(f'{host}:{port}', '=', self.uri, 'connected')
+        logging.info('connected %s:%s = %s', host, port, self.uri)
         self._buffer = []
         self._deadline = INF
         self._next_connect = 0
@@ -104,7 +105,7 @@ class Stream(Base):
         if self.socket is None:
             return
         self.select_read.pop(self.socket.fileno(), None)
-        print(self.uri, 'close socket')
+        logging.info('close socket %s', self.uri)
         try:
             self.socket.shutdown(socket.SHUT_RDWR)
         except socket.error:
@@ -130,10 +131,9 @@ class Stream(Base):
                     self.dead = min(now, self._last_live + 1)
                     return True
                 if self._deadline == INF:
-                    print(f'error "{e}" connecting to {self.uri} retrying for {self.max_offline} sec')
+                    logging.info(f'error %r connecting to %s retrying for %s sec',
+                                 e, self.uri, self.max_offline)
                     self._deadline = now + self.max_offline
-                else:
-                    print('.', end='', flush=True)
                 self._next_connect = now + 0.5
                 return True
         return False
@@ -163,7 +163,7 @@ class Stream(Base):
         now = time.time()
         if now > self._next_ping:
             if self._next_ping == self._ping_deadline:
-                print(self.uri, 'no pong')
+                self.log.info('no pong from %s', self.uri)
                 self.close()
                 return
             self.ping()
@@ -280,13 +280,13 @@ class EventStream:
                         stream = self.streams.get(uri)
                         if stream:
                             stream.tags.update(kwargs)
-                            print('update stream', uri, kwargs)
+                            logging.info('update stream %s %r', uri, kwargs)
                         else:
                             try:
                                 self.streams[uri] = stream = streamcls(uri, **kwargs)
-                                print('added stream', uri, kwargs)
+                                logging.info('added stream %s %r', uri, kwargs)
                             except Exception as e:
-                                print('can not connect to', uri, repr(e), streamcls)
+                                logging.warning('can not connect to %s %r %r', uri, e, streamcls)
                                 continue
                         device = stream.tags.get('device')
                         events.append(('stream', kwargs.get('instrument', ''),