###############################################################################
#
# The MIT License (MIT)
#
# Copyright (c) Crossbar.io Technologies GmbH
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# of this software and associated documentation files (the "Software"), to deal
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
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from __future__ import absolute_import, print_function
import six
import ssl # XXX what Python version is this always available at?
import signal
from functools import partial
try:
import asyncio
except ImportError:
# Trollius >= 0.3 was renamed to asyncio
# noinspection PyUnresolvedReferences
import trollius as asyncio
import txaio
txaio.use_asyncio() # noqa
from autobahn.asyncio.websocket import WampWebSocketClientFactory
from autobahn.asyncio.rawsocket import WampRawSocketClientFactory
from autobahn.wamp import component
from autobahn.asyncio.wamp import Session
__all__ = ('Component',)
def _unique_list(seq):
"""
Return a list with unique elements from sequence, preserving order.
"""
seen = set()
return [x for x in seq if x not in seen and not seen.add(x)]
def _create_transport_serializer(serializer_id):
if serializer_id in [u'msgpack', u'mgspack.batched']:
# try MsgPack WAMP serializer
try:
from autobahn.wamp.serializer import MsgPackSerializer
except ImportError:
pass
else:
if serializer_id == u'mgspack.batched':
return MsgPackSerializer(batched=True)
else:
return MsgPackSerializer()
if serializer_id in [u'json', u'json.batched']:
# try JSON WAMP serializer
try:
from autobahn.wamp.serializer import JsonSerializer
except ImportError:
pass
else:
if serializer_id == u'json.batched':
return JsonSerializer(batched=True)
else:
return JsonSerializer()
raise RuntimeError('could not create serializer for "{}"'.format(serializer_id))
def _create_transport_serializers(transport):
"""
Create a list of serializers to use with a WAMP protocol factory.
"""
serializers = []
for serializer_id in transport.serializers:
if serializer_id == u'msgpack':
# try MsgPack WAMP serializer
try:
from autobahn.wamp.serializer import MsgPackSerializer
except ImportError:
pass
else:
serializers.append(MsgPackSerializer(batched=True))
serializers.append(MsgPackSerializer())
elif serializer_id == u'json':
# try JSON WAMP serializer
try:
from autobahn.wamp.serializer import JsonSerializer
except ImportError:
pass
else:
serializers.append(JsonSerializer(batched=True))
serializers.append(JsonSerializer())
else:
raise RuntimeError(
"Unknown serializer '{}'".format(serializer_id)
)
return serializers
def _camel_case_from_snake_case(snake):
parts = snake.split('_')
return parts[0] + ''.join([s.capitalize() for s in parts[1:]])
def _create_transport_factory(loop, transport, session_factory):
"""
Create a WAMP-over-XXX transport factory.
"""
if transport.type == u'websocket':
serializers = _create_transport_serializers(transport)
factory = WampWebSocketClientFactory(session_factory, url=transport.url, serializers=serializers)
elif transport.type == u'rawsocket':
serializer = _create_transport_serializer(transport.serializers[0])
factory = WampRawSocketClientFactory(session_factory, serializer=serializer)
else:
assert(False), 'should not arrive here'
# set the options one at a time so we can give user better feedback
for k, v in transport.options.items():
try:
factory.setProtocolOptions(**{k: v})
except (TypeError, KeyError):
# this allows us to document options as snake_case
# until everything internally is upgraded from
# camelCase
try:
factory.setProtocolOptions(
**{_camel_case_from_snake_case(k): v}
)
except (TypeError, KeyError):
raise ValueError(
"Unknown {} transport option: {}={}".format(transport.type, k, v)
)
return factory
[docs]class Component(component.Component):
"""
A component establishes a transport and attached a session
to a realm using the transport for communication.
The transports a component tries to use can be configured,
as well as the auto-reconnect strategy.
"""
log = txaio.make_logger()
session_factory = Session
"""
The factory of the session we will instantiate.
"""
def _is_ssl_error(self, e):
"""
Internal helper.
"""
return isinstance(e, ssl.SSLError)
def _check_native_endpoint(self, endpoint):
if isinstance(endpoint, dict):
if u'tls' in endpoint:
tls = endpoint[u'tls']
if isinstance(tls, (dict, bool)):
pass
elif isinstance(tls, ssl.SSLContext):
pass
else:
raise ValueError(
"'tls' configuration must be a dict, bool or "
"SSLContext instance"
)
else:
raise ValueError(
"'endpoint' configuration must be a dict or IStreamClientEndpoint"
" provider"
)
# async function
def _connect_transport(self, loop, transport, session_factory):
"""
Create and connect a WAMP-over-XXX transport.
"""
factory = _create_transport_factory(loop, transport, session_factory)
if transport.endpoint[u'type'] == u'tcp':
version = transport.endpoint.get(u'version', 4)
if version not in [4, 6]:
raise ValueError('invalid IP version {} in client endpoint configuration'.format(version))
host = transport.endpoint[u'host']
if type(host) != six.text_type:
raise ValueError('invalid type {} for host in client endpoint configuration'.format(type(host)))
port = transport.endpoint[u'port']
if type(port) not in six.integer_types:
raise ValueError('invalid type {} for port in client endpoint configuration'.format(type(port)))
timeout = transport.endpoint.get(u'timeout', 10) # in seconds
if type(timeout) not in six.integer_types:
raise ValueError('invalid type {} for timeout in client endpoint configuration'.format(type(timeout)))
tls = transport.endpoint.get(u'tls', None)
tls_hostname = None
# create a TLS enabled connecting TCP socket
if tls:
if isinstance(tls, dict):
for k in tls.keys():
if k not in [u"hostname", u"trust_root"]:
raise ValueError("Invalid key '{}' in 'tls' config".format(k))
hostname = tls.get(u'hostname', host)
if type(hostname) != six.text_type:
raise ValueError('invalid type {} for hostname in TLS client endpoint configuration'.format(hostname))
cert_fname = tls.get(u'trust_root', None)
tls_hostname = hostname
tls = True
if cert_fname is not None:
tls = ssl.create_default_context(
purpose=ssl.Purpose.SERVER_AUTH,
cafile=cert_fname,
)
elif isinstance(tls, ssl.SSLContext):
# tls=<an SSLContext> is valid
tls_hostname = host
elif tls in [False, True]:
if tls:
tls_hostname = host
else:
raise RuntimeError('unknown type {} for "tls" configuration in transport'.format(type(tls)))
f = loop.create_connection(
protocol_factory=factory,
host=host,
port=port,
ssl=tls,
server_hostname=tls_hostname,
)
time_f = asyncio.ensure_future(asyncio.wait_for(f, timeout=timeout))
return time_f
elif transport.endpoint[u'type'] == u'unix':
path = transport.endpoint[u'path']
timeout = int(transport.endpoint.get(u'timeout', 10)) # in seconds
f = loop.create_unix_connection(
protocol_factory=factory,
path=path,
)
time_f = asyncio.ensure_future(asyncio.wait_for(f, timeout=timeout))
return time_f
else:
assert(False), 'should not arrive here'
# async function
def start(self, loop=None):
"""
This starts the Component, which means it will start connecting
(and re-connecting) to its configured transports. A Component
runs until it is "done", which means one of:
- There was a "main" function defined, and it completed successfully;
- Something called ``.leave()`` on our session, and we left successfully;
- ``.stop()`` was called, and completed successfully;
- none of our transports were able to connect successfully (failure);
:returns: a Future which will resolve (to ``None``) when we are
"done" or with an error if something went wrong.
"""
if loop is None:
self.log.warn("Using default loop")
loop = asyncio.get_event_loop()
return self._start(loop=loop)
[docs]def run(components, log_level='info'):
"""
High-level API to run a series of components.
This will only return once all the components have stopped
(including, possibly, after all re-connections have failed if you
have re-connections enabled). Under the hood, this calls
XXX fixme for asyncio
-- if you wish to manage the loop loop yourself, use the
:meth:`autobahn.asyncio.component.Component.start` method to start
each component yourself.
:param components: the Component(s) you wish to run
:type components: Component or list of Components
:param log_level: a valid log-level (or None to avoid calling start_logging)
:type log_level: string
"""
# actually, should we even let people "not start" the logging? I'm
# not sure that's wise... (double-check: if they already called
# txaio.start_logging() what happens if we call it again?)
if log_level is not None:
txaio.start_logging(level=log_level)
loop = asyncio.get_event_loop()
if loop.is_closed():
asyncio.set_event_loop(asyncio.new_event_loop())
loop = asyncio.get_event_loop()
txaio.config.loop = loop
log = txaio.make_logger()
# see https://github.com/python/asyncio/issues/341 asyncio has
# "odd" handling of KeyboardInterrupt when using Tasks (as
# run_until_complete does). Another option is to just resture
# default SIGINT handling, which is to exit:
# import signal
# signal.signal(signal.SIGINT, signal.SIG_DFL)
@asyncio.coroutine
def exit():
return loop.stop()
def nicely_exit(signal):
log.info("Shutting down due to {signal}", signal=signal)
for task in asyncio.Task.all_tasks():
task.cancel()
asyncio.ensure_future(exit())
try:
loop.add_signal_handler(signal.SIGINT, partial(nicely_exit, 'SIGINT'))
loop.add_signal_handler(signal.SIGTERM, partial(nicely_exit, 'SIGTERM'))
except NotImplementedError:
# signals are not available on Windows
pass
def done_callback(loop, arg):
loop.stop()
# returns a future; could run_until_complete() but see below
component._run(loop, components, done_callback)
try:
loop.run_forever()
# this is probably more-correct, but then you always get
# "Event loop stopped before Future completed":
# loop.run_until_complete(f)
except asyncio.CancelledError:
pass
# finally:
# signal.signal(signal.SIGINT, signal.SIG_DFL)
# signal.signal(signal.SIGTERM, signal.SIG_DFL)
# Close the event loop at the end, otherwise an exception is
# thrown. https://bugs.python.org/issue23548
loop.close()