[fix] create monitor socket before connect

Change the `wait_connected` method to a `connect` method with an
optional wait. Ensure that the actual connect call on the socket is done
after the monitor is created, otherwise the monitor might miss the
connection event.

bin/argo-perf-wrapper

@@ -53,7 +53,7 @@ class PerfWrapper(object):
     def setup(self):
         downstream_url = "ipc:///tmp/nrm-downstream-event"
         self.downstream_event = messaging.DownstreamEventClient(downstream_url)
-        self.downstream_event.wait_connected()
+        self.downstream_event.connect()
         logger.info("downstream pub socket connected to: %s", downstream_url)
 
         # retrieve our container uuid

bin/cmd

@@ -59,14 +59,14 @@ class CommandLineInterface(object):
             self.do_signal(None, signum, frame)
         signal.signal(signal.SIGINT, handler)
 
-        self.client.wait_connected()
+        self.client.connect()
 
     def do_listen(self, argv):
         """ Connect to the NRM and listen for pub/sub messages."""
         upstream_pub_port = 2345
         upstream_pub_param = "tcp://localhost:%d" % (upstream_pub_port)
         self.pub_client = nrm.messaging.UpstreamPubClient(upstream_pub_param)
-        self.pub_client.wait_connected()
+        self.pub_client.connect()
 
         while(True):
             msg = self.pub_client.recvmsg()

nrm/messaging.py

@@ -175,12 +175,12 @@ class UpstreamRPCClient(object):
         self.zmq_context = zmq.Context.instance()
         self.socket = self.zmq_context.socket(zmq.DEALER)
         self.socket.setsockopt(zmq.IDENTITY, self.uuid)
-        self.socket.connect(address)
 
-    def wait_connected(self):
-        """Creates a monitor socket and wait for the connect event."""
+    def connect(self, wait=True):
+        """Connect, and wait for the socket to be connected."""
         monitor = self.socket.get_monitor_socket()
-        while True:
+        self.socket.connect(self.address)
+        while wait:
             msg = zmq.utils.monitor.recv_monitor_message(monitor)
             logger.debug("monitor message: %r", msg)
             if int(msg['event']) == zmq.EVENT_CONNECTED:
@@ -264,12 +264,12 @@ class UpstreamPubClient(object):
         self.zmq_context = zmq.Context.instance()
         self.socket = self.zmq_context.socket(zmq.SUB)
         self.socket.setsockopt(zmq.SUBSCRIBE, '')
-        self.socket.connect(address)
 
-    def wait_connected(self):
+    def connect(self, wait=True):
         """Creates a monitor socket and wait for the connect event."""
         monitor = self.socket.get_monitor_socket()
-        while True:
+        self.socket.connect(self.address)
+        while wait:
             msg = zmq.utils.monitor.recv_monitor_message(monitor)
             logger.debug("monitor message: %r", msg)
             if int(msg['event']) == zmq.EVENT_CONNECTED:

test/test_messaging.py

@@ -76,7 +76,7 @@ def test_msg_convertion(dummy_msg):
 
 
 def test_rpc_connection(upstream_rpc_client, upstream_rpc_server):
-    upstream_rpc_client.wait_connected()
+    upstream_rpc_client.connect()
 
 
 def test_rpc_send_recv(upstream_rpc_client, upstream_rpc_server, dummy_msg):
@@ -104,7 +104,7 @@ def test_pub_server_send(upstream_pub_server, dummy_msg):
 
 
 def test_pub_connection(upstream_pub_client, upstream_pub_server):
-    upstream_pub_client.wait_connected()
+    upstream_pub_client.connect()
 
 
 def test_pub_client_recv(upstream_pub_server, upstream_pub_client, dummy_msg):
@@ -114,7 +114,7 @@ def test_pub_client_recv(upstream_pub_server, upstream_pub_client, dummy_msg):
 
 
 def test_down_connection(downstream_event_client, downstream_event_server):
-    downstream_event_client.wait_connected()
+    downstream_event_client.connect()
 
 
 def test_down_event_send_recv(downstream_event_client, downstream_event_server,