def main():
# Declare the protocol stack used for serialization.
# Protocol stacks must match between clients and servers.
prot_factory = FProtocolFactory(TBinaryProtocol.TBinaryProtocolFactory())
# Open a NATS connection to send requests
nats_client = NATS()
options = {"verbose": True, "servers": ["nats://127.0.0.1:4222"]}
yield nats_client.connect(**options)
# Create a nats transport using the connected client
# The transport sends data on the music-service NATS topic
nats_transport = FNatsTransport(nats_client, "music-service")
try:
yield nats_transport.open()
except TTransportException as ex:
root.error(ex)
raise gen.Return()
# Using the configured transport and protocol, create a client
# to talk to the music store service.
store_client = FStoreClient(FServiceProvider(nats_transport, prot_factory),
middleware=logging_middleware)
album = yield store_client.buyAlbum(FContext(), str(uuid.uuid4()),
"ACT-12345")
root.info("Bought an album %s\n", album)
yield store_client.enterAlbumGiveaway(FContext(), "*****@*****.**",
"Kevin")
yield nats_transport.close()
yield nats_client.close()
def main():
parser = argparse.ArgumentParser(description="Run a python tornado client")
parser.add_argument('--port', dest='port', default='9090')
parser.add_argument('--protocol',
dest='protocol_type',
default="binary",
choices="binary, compact, json")
parser.add_argument('--transport',
dest='transport_type',
default=NATS_NAME,
choices="nats, http")
args = parser.parse_args()
protocol_factory = get_protocol_factory(args.protocol_type)
nats_client = NATS()
logging.debug("Connecting to NATS")
yield nats_client.connect(**get_nats_options())
transport = None
if args.transport_type == NATS_NAME:
transport = FNatsTransport(nats_client,
"frugal.foo.bar.rpc.{}".format(args.port))
elif args.transport_type == HTTP_NAME:
# Set request and response capacity to 1mb
max_size = 1048576
transport = FHttpTransport("http://localhost:" + str(args.port),
request_capacity=max_size,
response_capacity=max_size)
else:
print("Unknown transport type: {}".format(args.transport_type))
sys.exit(1)
try:
yield transport.open()
except TTransportException as ex:
logging.error(ex)
raise gen.Return()
client = FrugalTestClient(FServiceProvider(transport, protocol_factory),
client_middleware)
ctx = FContext("test")
yield test_rpc(client, ctx, args.transport_type)
if transport == NATS_NAME:
yield test_pub_sub(nats_client, protocol_factory, args.port)
global middleware_called
if not middleware_called:
print("Client middleware never invoked")
exit(1)
# Cleanup after tests
yield nats_client.close()
def test_close_connection(self):
nc = Client()
options = {
"dont_randomize": True,
"servers": [
"nats://*****:*****@127.0.0.1:4223",
"nats://*****:*****@127.0.0.1:4224"
],
"io_loop": self.io_loop
}
yield nc.connect(**options)
self.assertEqual(True, nc._server_info["auth_required"])
log = Log()
sid_1 = yield nc.subscribe("foo", "", log.persist)
self.assertEqual(sid_1, 1)
sid_2 = yield nc.subscribe("bar", "", log.persist)
self.assertEqual(sid_2, 2)
sid_3 = yield nc.subscribe("quux", "", log.persist)
self.assertEqual(sid_3, 3)
yield nc.publish("foo", "hello")
yield tornado.gen.sleep(1.0)
# Done
yield nc.close()
orig_gnatsd = self.server_pool.pop(0)
orig_gnatsd.finish()
try:
a = nc._current_server
# Wait and assert that we don't reconnect.
yield tornado.gen.sleep(3)
finally:
b = nc._current_server
self.assertEqual(a.uri, b.uri)
self.assertFalse(nc.is_connected())
self.assertFalse(nc.is_reconnecting())
self.assertTrue(nc.is_closed())
with(self.assertRaises(ErrConnectionClosed)):
yield nc.publish("hello", "world")
with(self.assertRaises(ErrConnectionClosed)):
yield nc.flush()
with(self.assertRaises(ErrConnectionClosed)):
yield nc.subscribe("hello", "worker")
with(self.assertRaises(ErrConnectionClosed)):
yield nc.publish_request("hello", "inbox", "world")
with(self.assertRaises(ErrConnectionClosed)):
yield nc.request("hello", "world")
with(self.assertRaises(ErrConnectionClosed)):
yield nc.timed_request("hello", "world")
def main():
nc = NATS()
# Set pool servers in the cluster and give a name to the client
# each with its own auth credentials.
options = {
"servers": [
"nats://*****:*****@127.0.0.1:4222",
"nats://*****:*****@127.0.0.1:4223",
"nats://*****:*****@127.0.0.1:4224"
]
}
# Error callback takes the error type as param.
def error_cb(e):
print("Error! ", e)
def close_cb():
print("Connection was closed!")
def disconnected_cb():
print("Disconnected!")
def reconnected_cb():
print("Reconnected!")
# Set callback to be dispatched whenever we get
# protocol error message from the server.
options["error_cb"] = error_cb
# Called when we are not connected anymore to the NATS cluster.
options["closed_cb"] = close_cb
# Called whenever we become disconnected from a NATS server.
options["disconnected_cb"] = disconnected_cb
# Called when we connect to a node in the NATS cluster again.
options["reconnected_cb"] = reconnected_cb
yield nc.connect(**options)
@tornado.gen.coroutine
def subscriber(msg):
yield nc.publish("pong", "pong:{0}".format(msg.data))
yield nc.subscribe("ping", "", subscriber)
for i in range(0, 100):
yield nc.publish("ping", "ping:{0}".format(i))
yield tornado.gen.sleep(0.1)
yield nc.close()
try:
yield nc.publish("ping", "ping")
except ErrConnectionClosed:
print("No longer connected to NATS cluster.")
def go(loop):
nc = NATS()
try:
yield from nc.connect(io_loop=loop)
except:
pass
def message_handler(msg):
print("[Received on '{}']: {}".format(msg.subject, msg.data.decode()))
try:
# Interested in receiving 2 messages from the 'discover' subject.
sid = yield from nc.subscribe("discover", "", message_handler)
yield from nc.auto_unsubscribe(sid, 2)
yield from nc.publish("discover", b'hello')
yield from nc.publish("discover", b'world')
# Following 2 messages won't be received.
yield from nc.publish("discover", b'again')
yield from nc.publish("discover", b'!!!!!')
except ErrConnectionClosed:
print("Connection closed prematurely")
def request_handler(msg):
print("[Request on '{} {}']: {}".format(msg.subject, msg.reply, msg.data.decode()))
if nc.is_connected:
# Subscription using a 'workers' queue so that only a single subscriber
# gets a request at a time.
yield from nc.subscribe("help", "workers", request_handler)
try:
# Make a request expecting a single response within 500 ms,
# otherwise raising a timeout error.
response = yield from nc.timed_request("help", b'help please', 0.500)
print("[Response]: {}".format(msg.data))
# Make a roundtrip to the server to ensure messages
# that sent messages have been processed already.
yield from nc.flush(0.500)
except ErrTimeout:
print("[Error] Timeout!")
# Wait a bit for message to be dispatched...
yield from asyncio.sleep(1, loop=loop)
# Detach from the server.
yield from nc.close()
if nc.last_error is not None:
print("Last Error: {}".format(nc.last_error))
if nc.is_closed:
print("Disconnected.")
def main():
nc = NATS()
# Set pool servers in the cluster and give a name to the client
# each with its own auth credentials.
options = {
"servers": [
"nats://*****:*****@127.0.0.1:4222",
"nats://*****:*****@127.0.0.1:4223",
"nats://*****:*****@127.0.0.1:4224"
]
}
# Error callback takes the error type as param.
def error_cb(e):
print("Error! ", e)
def close_cb():
print("Connection was closed!")
def disconnected_cb():
print("Disconnected!")
def reconnected_cb():
print("Reconnected!")
# Set callback to be dispatched whenever we get
# protocol error message from the server.
options["error_cb"] = error_cb
# Called when we are not connected anymore to the NATS cluster.
options["close_cb"] = close_cb
# Called whenever we become disconnected from a NATS server.
options["disconnected_cb"] = disconnected_cb
# Called when we connect to a node in the NATS cluster again.
options["reconnected_cb"] = reconnected_cb
yield nc.connect(**options)
@tornado.gen.coroutine
def subscriber(msg):
yield nc.publish("pong", "pong:{0}".format(msg.data))
yield nc.subscribe("ping", "", subscriber)
for i in range(0, 100):
yield nc.publish("ping", "ping:{0}".format(i))
yield tornado.gen.sleep(0.1)
yield nc.close()
try:
yield nc.publish("ping", "ping")
except ErrConnectionClosed:
print("No longer connected to NATS cluster.")
def main():
nc = NATS()
# Establish connection to the server.
yield nc.connect("nats://demo.nats.io:4222")
@tornado.gen.coroutine
def message_handler(msg):
subject = msg.subject
data = msg.data
print("[Received on '{}'] : {}".format(subject, data.decode()))
# Simple async subscriber
sid = yield nc.subscribe("foo", cb=message_handler)
# Stop receiving after 2 messages.
yield nc.auto_unsubscribe(sid, 2)
yield nc.publish("foo", b'Hello')
yield nc.publish("foo", b'World')
yield nc.publish("foo", b'!!!!!')
# Request/Response
@tornado.gen.coroutine
def help_request_handler(msg):
print("[Received on '{}']: {}".format(msg.subject, msg.data))
yield nc.publish(msg.reply, "OK, I can help!")
# Susbcription using distributed queue named 'workers'
sid = yield nc.subscribe("help", "workers", help_request_handler)
try:
# Send a request and expect a single response
# and trigger timeout if not faster than 200 ms.
msg = yield nc.request("help", b"Hi, need help!", timeout=0.2)
print("[Response]: %s" % msg.data)
except tornado.gen.TimeoutError:
print("Response Timeout!")
# Remove interest in subscription.
yield nc.unsubscribe(sid)
# Terminate connection to NATS.
yield nc.close()
def main():
# Declare the protocol stack used for serialization.
# Protocol stacks must match between publishers and subscribers.
prot_factory = FProtocolFactory(TBinaryProtocol.TBinaryProtocolFactory())
# Open a NATS connection to receive requests
nats_client = NATS()
options = {"verbose": True, "servers": ["nats://127.0.0.1:4222"]}
yield nats_client.connect(**options)
# Create a pub sub scope using the configured transport and protocol
transport_factory = FNatsPublisherTransportFactory(nats_client)
provider = FScopeProvider(transport_factory, None, prot_factory)
# Create a publisher
publisher = AlbumWinnersPublisher(provider)
yield publisher.open()
# Publish an album win event
album = Album()
album.ASIN = str(uuid.uuid4())
album.duration = 12000
album.tracks = [
Track(title="Comme des enfants",
artist="Coeur de pirate",
publisher="Grosse Boîte",
composer="Béatrice Martin",
duration=169,
pro=PerfRightsOrg.ASCAP)
]
yield publisher.publish_Winner(FContext(), album)
yield publisher.publish_ContestStart(FContext(), [album, album])
yield publisher.close()
yield nats_client.close()
def nats(server, subject, msg):
"""
NATS client implemented via tornado (NATS py2 approach), see
https://github.com/nats-io/nats.py2
"""
nc = NATS()
try:
yield nc.connect(server, max_reconnect_attempts=3)
except Exception as exp:
print("failed to connect to server: error {}".format(str(exp)))
traceback.print_exc()
return
if isinstance(msg, list):
for item in msg:
yield nc.publish(subject, item)
else:
yield nc.publish(subject, msg)
# Drain gracefully closes the connection, allowing all subscribers to
# handle any pending messages inflight that the server may have sent.
yield nc.drain()
# Drain works async in the background
#yield tornado.gen.sleep(1)
yield nc.close()
