157 lines
5.1 KiB
Python
157 lines
5.1 KiB
Python
import argparse
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import logging
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import sys
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import traceback
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from threading import Thread
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from getopt import getopt
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from .bus import Bus
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from .config import Config
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from .utils import get_or_load_plugin, init_backends, get_module_and_name_from_action
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from .message.event import Event, StopEvent
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from .message.request import Request
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from .message.response import Response
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__author__ = 'Fabio Manganiello <info@fabiomanganiello.com>'
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__version__ = '0.4'
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#-----------#
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class Daemon(object):
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""" Main class for the Platypush daemon """
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""" Configuration file (default: either ~/.config/platypush/config.yaml or
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/etc/platypush/config.yaml) """
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config_file = None
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""" Application bus. It's an internal queue where:
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- backends will post the messages they receive
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- plugins will post the responses they process """
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bus = None
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""" backend_name => backend_obj map """
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backends = None
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""" number of executions retries before a request fails """
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n_tries = 2
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def __init__(self, config_file=None):
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""" Constructor
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Params:
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config_file -- Configuration file override (default: None)
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"""
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self.config_file = config_file
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Config.init(self.config_file)
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logging.basicConfig(level=Config.get('logging'), stream=sys.stdout)
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@classmethod
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def build_from_cmdline(cls, args):
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""" Build the app from command line arguments.
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Params:
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args -- Your sys.argv[1:] [List of strings]
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"""
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parser = argparse.ArgumentParser()
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parser.add_argument('--config', '-c', dest='config', required=False,
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default=None, help=cls.config_file.__doc__)
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opts, args = parser.parse_known_args(args)
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return cls(config_file=opts.config)
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def on_message(self):
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""" Default message handler """
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def _f(msg):
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""" on_message closure
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Params:
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msg -- platypush.message.Message instance """
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if isinstance(msg, Request):
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logging.info('Processing request: {}'.format(msg))
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Thread(target=self.run_request(), args=(msg,)).start()
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elif isinstance(msg, Response):
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logging.info('Received response: {}'.format(msg))
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return _f
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def send_response(self, request, response):
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""" Sends a response back.
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Params:
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request -- The platypush.message.request.Request object
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response -- The platypush.message.response.Response object """
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if request.backend and request.origin:
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if request.id: response.id = request.id
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response.target = request.origin
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logging.info('Processing response: {}'.format(response))
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request.backend.send_response(response)
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else:
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logging.info('Ignoring response as the request has no backend: '
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.format(request))
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def run_request(self):
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""" Runs a request and returns the response """
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def _thread_func(request, n_tries=self.n_tries):
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""" Thread closure method
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Params:
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request - platypush.message.request.Request object """
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(module_name, method_name) = get_module_and_name_from_action(request.action)
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try:
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plugin = get_or_load_plugin(module_name)
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except RuntimeError as e: # Module/class not found
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logging.exception(e)
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return
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try:
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# Run the action
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response = plugin.run(method=method_name, **request.args)
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if response and response.is_error():
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logging.warning('Response processed with errors: {}'.format(response))
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except Exception as e: # Retry mechanism
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response = Response(output=None, errors=[str(e), traceback.format_exc()])
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logging.exception(e)
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if n_tries:
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logging.info('Reloading plugin {} and retrying'.format(module_name))
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get_or_load_plugin(module_name, reload=True)
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_thread_func(request, n_tries=n_tries-1)
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finally:
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# Send the response on the backend that received the request
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self.send_response(request, response)
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return _thread_func
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def start(self):
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""" Start the daemon """
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self.bus = Bus(on_message=self.on_message())
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# Initialize the backends and link them to the bus
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self.backends = init_backends(self.bus)
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# Start the backend threads
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for backend in self.backends.values():
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backend.start()
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# Poll for messages on the bus
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try:
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self.bus.poll()
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except KeyboardInterrupt as e:
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logging.info('SIGINT received, terminating application')
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for backend in self.backends.values():
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backend.stop()
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def main(args=sys.argv[1:]):
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print('Starting platypush v.{}'.format(__version__))
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app = Daemon.build_from_cmdline(args)
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app.start()
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if __name__ == '__main__':
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main()
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# vim:sw=4:ts=4:et:
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