def call_method(self, name, method, params):
"""Call a previously registered subsystem method by name. Only
methods tagged with the @api_call decorator can be called.
:param name: Assigned name of the registered subsystem.
:type name: string
:param method: Subsystem method to be called.
:type method: string
:param params: Additional parameters for the called method.
:type params: dict
:returns: call_reply or error message dict to be sent to caller.
"""
self.logger.debug("API call: {}.{}({})".format(name, method, params))
if name in self.systems:
obj = self.systems[name]
if is_api_method(obj, method):
try:
# Calls given obj.method, unpacking and passing params dict
call_return = getattr(obj, method)(**params)
msg = "Called {}.{}".format(name, method)
self.logger.debug(msg + ",returned:{}".format(call_return))
return msgs.call_reply(msg, call_return)
except TypeError:
# Raised when we have a mismatch of the method's kwargs
# TODO: Return argspec here?
err_msg = "Invalid params for {}.{}".format(name, method)
self.logger.warning(err_msg)
return msgs.error(err_msg)
except Exception as e:
# Catch exception raised by called method, notify client
err_msg = "Exception: '{}'".format(str(e))
self.logger.warning(err_msg)
return msgs.error(err_msg)
else:
err_msg = "Invalid method: '{}.{}'".format(name, method)
self.logger.warning(err_msg)
return msgs.error(err_msg)
else:
err_msg = "Invalid object: '{}'".format(name)
self.logger.warning(err_msg)
return msgs.error(err_msg)
def call_method(self, name, method, params):
"""Call a previously registered subsystem method by name. Only
methods tagged with the @api_call decorator can be called.
:param name: Assigned name of the registered subsystem.
:type name: string
:param method: Subsystem method to be called.
:type method: string
:param params: Additional parameters for the called method.
:type params: dict
:returns: call_reply or error message dict to be sent to caller.
"""
self.logger.debug("API call: {}.{}({})".format(name, method, params))
if name in self.systems:
obj = self.systems[name]
if is_api_method(obj, method):
try:
# Calls given obj.method, unpacking and passing params dict
call_return = getattr(obj, method)(**params)
msg = "Called {}.{}".format(name, method)
self.logger.debug(msg + ",returned:{}".format(call_return))
return msgs.call_reply(msg, call_return)
except TypeError:
# Raised when we have a mismatch of the method's kwargs
# TODO: Return argspec here?
err_msg = "Invalid params for {}.{}".format(name, method)
self.logger.warning(err_msg)
return msgs.error(err_msg)
except Exception as e:
# Catch exception raised by called method, notify client
err_msg = "Exception: '{}'".format(str(e))
self.logger.warning(err_msg)
return msgs.error(err_msg)
else:
err_msg = "Invalid method: '{}.{}'".format(name, method)
self.logger.warning(err_msg)
return msgs.error(err_msg)
else:
err_msg = "Invalid object: '{}'".format(name)
self.logger.warning(err_msg)
return msgs.error(err_msg)
def handle_msg(self, msg):
"""Generic message handler. Hands-off based on type of message.
:param msg: Message, received via ZMQ from client, to handle.
:type msg: dict
:returns: An appropriate message reply dict, from lib.messages.
"""
self.logger.debug("Received: {}".format(msg))
try:
msg_type = msg["type"]
except KeyError as e:
return msgs.error(e)
if msg_type == "ping_req":
reply = msgs.ping_reply()
elif msg_type == "list_req":
reply = self.list_callables()
elif msg_type == "call_req":
try:
obj_name = msg["obj_name"]
method = msg["method"]
params = msg["params"]
reply = self.call_method(obj_name, method, params)
except KeyError as e:
return msgs.error(e)
elif msg_type == "exit_req":
self.logger.info("Received message to die. Bye!")
reply = msgs.exit_reply()
# Need to actually send reply here as we're about to exit
self.logger.debug("Sending: {}".format(reply))
self.ctrl_sock.send_json(reply)
self.clean_up()
sys.exit(0)
else:
err_msg = "Unrecognized message: {}".format(msg)
self.logger.warning(err_msg)
reply = msgs.error(err_msg)
return reply
def handle_msg(self, msg):
"""Generic message handler. Hands-off based on type of message.
:param msg: Message, received via ZMQ from client, to handle.
:type msg: dict
:returns: An appropriate message reply dict, from lib.messages.
"""
self.logger.debug("Received: {}".format(msg))
try:
msg_type = msg["type"]
except KeyError as e:
return msgs.error(e)
if msg_type == "ping_req":
reply = msgs.ping_reply()
elif msg_type == "list_req":
reply = self.list_callables()
elif msg_type == "call_req":
try:
obj_name = msg["obj_name"]
method = msg["method"]
params = msg["params"]
reply = self.call_method(obj_name, method, params)
except KeyError as e:
return msgs.error(e)
elif msg_type == "exit_req":
self.logger.info("Received message to die. Bye!")
reply = msgs.exit_reply()
# Need to actually send reply here as we're about to exit
self.logger.debug("Sending: {}".format(reply))
self.ctrl_sock.send_json(reply)
self.clean_up()
sys.exit(0)
else:
err_msg = "Unrecognized message: {}".format(msg)
self.logger.warning(err_msg)
reply = msgs.error(err_msg)
return reply
def listen(self):
"""Perpetually listen for messages, pass them to generic handler."""
self.logger.info("Control server: {}".format(self.server_bind_addr))
while True:
try:
msg = self.ctrl_sock.recv_json()
reply = self.handle_msg(msg)
self.logger.debug("Sending: {}".format(reply))
self.ctrl_sock.send_json(reply)
except JSONDecodeError:
err_msg = "Not a JSON message!"
self.logger.warning(err_msg)
self.ctrl_sock.send_json(msgs.error(err_msg))
except KeyboardInterrupt:
self.logger.info("Exiting control server. Bye!")
self.clean_up()
sys.exit(0)
def listen(self):
"""Perpetually listen for messages, pass them to generic handler."""
self.logger.info("Control server: {}".format(self.server_bind_addr))
while True:
try:
msg = self.ctrl_sock.recv_json()
reply = self.handle_msg(msg)
self.logger.debug("Sending: {}".format(reply))
self.ctrl_sock.send_json(reply)
except JSONDecodeError:
err_msg = "Not a JSON message!"
self.logger.warning(err_msg)
self.ctrl_sock.send_json(msgs.error(err_msg))
except KeyboardInterrupt:
self.logger.info("Exiting control server. Bye!")
self.clean_up()
sys.exit(0)
