ZeroMQ publisher plugin

zmq/example-subscriber.py

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+#!/usr/bin/env python3
+# Copyright (c) 2019 lightningd
+# Distributed under the BSD 3-Clause License, see the accompanying file LICENSE
+
+###############################################################################
+# An example ZeroMQ subscriber client for the plugin.
+#
+# This module connects and subscribes to ZeroMQ endpoints, decodes the messages
+# and simply logs the JSON payload to stdout.
+#
+# It also uses Twisted and txZMQ frameworks, but on the subscriber side.
+#
+# To use, the plugin must be loaded for lightningd and the parameters must be
+# given as launch arguments to publish notifications at given endpoints.
+# Eg. for publishing 'connect' and 'disconnect' notifications:.
+# $ lightningd --zmq-pub-connect=ipc:///tmp/cl-zmq  \
+#              --zmq-pub-disconnect=tcp://127.0.0.1:5555
+#
+# The client must then be started with arguments for the same endpoints.
+# Eg. to subscribe to those 'connect' and 'disconnect' notifications:
+#
+# $ python3 example-subscriber.py --zmq-sub-connect=ipc:///tmp/cl-zmq \
+#                                 --zmq-sub-disconnect=tcp://127.0.0.1:5555
+#
+# You can test receiving the subscription by connecting and disconnecting from
+# nodes on the network:
+# Eg.
+# $ lightning-cli connect <node-id>
+# $ lightning-cli disconnect <node-id>
+#
+###############################################################################
+
+import time
+import json
+import argparse
+
+from twisted.internet import reactor
+from twisted.internet.task import LoopingCall
+
+from txzmq import ZmqEndpoint, ZmqEndpointType
+from txzmq import ZmqFactory
+from txzmq import ZmqSubConnection
+
+###############################################################################
+
+NOTIFICATION_TYPE_NAMES = ['channel_opened',
+                           'connect',
+                           'disconnect',
+                           'invoice_payment',
+                           'warning',
+                           'forward_event',
+                           'sendpay_success',
+                           'sendpay_failure']
+
+class NotificationType():
+    def __init__(self, notification_type_name):
+        self.notification_type_name = notification_type_name
+
+    def __str__(self):
+        return self.notification_type_name
+
+    def endpoint_option(self):
+        return "zmq-sub-{}".format(str(self).replace("_", "-"))
+
+    def argparse_namespace_attribute(self):
+        return "zmq_sub_{}".format((self))
+
+NOTIFICATION_TYPES = [NotificationType(n) for n in NOTIFICATION_TYPE_NAMES]
+
+###############################################################################
+
+class Subscriber():
+    def __init__(self):
+        self.factory = ZmqFactory()
+
+    def _log_message(self, message, tag):
+        tag = tag.decode("utf8")
+        message = json.dumps(json.loads(message.decode("utf8")), indent=1,
+                              sort_keys=True)
+        current_time = time.strftime('%X %x %Z')
+        print("{} - {}\n{}".format(current_time, tag, message))
+
+    def _load_setup(self, setup):
+        for e, notification_type_names in setup.items():
+            endpoint = ZmqEndpoint(ZmqEndpointType.connect, e)
+            connection = ZmqSubConnection(self.factory, endpoint)
+            for n in notification_type_names:
+                tag = n.encode("utf8")
+                connection.gotMessage = self._log_message
+                connection.subscribe(tag)
+
+    def parse_and_load_settings(self, settings):
+        setup = {}
+        for nt in NOTIFICATION_TYPES:
+            attr = nt.argparse_namespace_attribute()
+            endpoint = getattr(settings, attr)
+            if endpoint is None:
+                continue
+            if endpoint not in setup:
+                setup[endpoint] = []
+            setup[endpoint].append(str(nt))
+        self._load_setup(setup)
+
+
+###############################################################################
+
+parser = argparse.ArgumentParser(prog="example-subscriber.py")
+for nt in NOTIFICATION_TYPES:
+    h = "subscribe to {} events published from this endpoint".format(nt)
+    parser.add_argument('--' + nt.endpoint_option(), type=str, help=h)
+settings = parser.parse_args()
+
+subscriber = Subscriber()
+subscriber.parse_and_load_settings(settings)
+reactor.run()