import signal
import socket
+import formencode
+import logging ; log = logging.getLogger('pymin.pymindaemon')
+from pymin.dispatcher import handler
+from pymin import dispatcher
from pymin import eventloop
from pymin import serializer
+from pymin import procman
class PyminDaemon(eventloop.EventLoop):
- r"""PyminDaemon(bind_addr, routes) -> PyminDaemon instance
+ r"""PyminDaemon(root, bind_addr) -> PyminDaemon instance
This class is well suited to run as a single process. It handles
signals for controlled termination (SIGINT and SIGTERM), as well as
a user signal to reload the configuration files (SIGUSR1).
- bind_addr - is a tuple of (ip, port) where to bind the UDP socket to.
+ root - the root handler. This is passed directly to the Dispatcher.
- routes - is a dictionary where the key is a command string and the value
- is the command handler. This is passed directly to the Dispatcher.
+ bind_addr - is a tuple of (ip, port) where to bind the UDP socket to.
Here is a simple usage example:
- >>> def test_handler(*args): print 'test:', args
- >>> PyminDaemon(('', 9999), dict(test=test_handler)).run()
+ >>> from pymin import dispatcher
+ >>> class Root(dispatcher.Handler):
+ @handler('Test command.')
+ def test(self, *args):
+ print 'test:', args
+ >>> PyminDaemon(Root(), ('', 9999)).run()
+
+ The daemon then will be listening to messages to UDP port 9999. Messages
+ will be dispatcher throgh the pymin.dispatcher mechanism. If all goes ok,
+ an OK response is sent. If there was a problem, an ERROR response is sent.
+
+ The general syntax of responses is::
+
+ (OK|ERROR) LENGTH
+ CSV MESSAGE
+
+ So, first is a response code (OK or ERROR), then it comes the length of
+ the CSV MESSAGE (the bufer needed to receive the rest of the message).
+
+ CSV MESSAGE is the body of the response, which it could be void (if lenght
+ is 0), a simple string (a CVS with only one column and row), a single row
+ or a full "table" (a CSV with multiple rows and columns).
+
+ There are 2 kind of errors considered "normal": dispatcher.Error and
+ formencode.Invalid. In general, response bodies of errors are simple
+ strings, except, for example, for formencode.Invalid errors where an
+ error_dict is provided. In that case the error is a "table", where the
+ first colunm is the name of an invalid argument, and the second is the
+ description of the error for that argument. Any other kind of exception
+ raised by the handlers will return an ERROR response with the description
+ "Internal server error".
+
+ All messages (requests and responses) should be UTF-8 encoded and the CVS
+ responses are formated in "Excel" format, as known by the csv module.
"""
- def __init__(self, routes=dict(), bind_addr=('', 9999)):
+ def __init__(self, root, bind_addr=('', 9999), timer=1):
r"""Initialize the PyminDaemon object.
See PyminDaemon class documentation for more info.
"""
+ log.debug(u'PyminDaemon(%r, %r, %r)', root, bind_addr, timer)
+ # Timer timeout time
+ self.timer = timer
# Create and bind socket
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(bind_addr)
- # Create EventLoop
- eventloop.EventLoop.__init__(self, sock)
- # Create Dispatcher
- self.dispatcher = Dispatcher(routes)
# Signal handling
- def quit(signum, frame):
- print "Shuting down ..."
- self.stop() # tell main event loop to stop
- def reload_config(signum, frame):
- print "Reloading configuration..."
+ def quit(loop, signum):
+ log.debug(u'PyminDaemon quit() handler: signal %r', signum)
+ log.info(u'Shutting down...')
+ loop.stop() # tell main event loop to stop
+ def reload_config(loop, signum):
+ log.debug(u'PyminDaemon reload_config() handler: signal %r', signum)
+ log.info(u'Reloading configuration...')
# TODO iterate handlers list propagating reload action
- signal.signal(signal.SIGINT, quit)
- signal.signal(signal.SIGTERM, quit)
- signal.signal(signal.SIGUSR1, reload_config)
+ def timer(loop, signum):
+ loop.handle_timer()
+ signal.alarm(loop.timer)
+ def child(loop, signum):
+ procman.sigchild_handler(signum)
+ # Create EventLoop
+ eventloop.EventLoop.__init__(self, sock, signals={
+ signal.SIGINT: quit,
+ signal.SIGTERM: quit,
+ signal.SIGUSR1: reload_config,
+ signal.SIGALRM: timer,
+ signal.SIGCHLD: child,
+ })
+ # Create Dispatcher
+ #TODO root.pymin = PyminHandler()
+ self.dispatcher = dispatcher.Dispatcher(root)
def handle(self):
r"handle() -> None :: Handle incoming events using the dispatcher."
(msg, addr) = self.file.recvfrom(65535)
+ log.debug(u'PyminDaemon.handle: message %r from %r', msg, addr)
+ response = u'ERROR'
try:
- result = self.dispatcher.dispatch(msg)
+ result = self.dispatcher.dispatch(unicode(msg, 'utf-8'))
if result is not None:
- result = serializer.serialize(result)
- response = u'OK '
+ result = unicode(serializer.serialize(result), 'utf-8')
+ response = u'OK'
except dispatcher.Error, e:
result = unicode(e) + u'\n'
- response = u'ERROR '
+ except formencode.Invalid, e:
+ if e.error_dict:
+ result = unicode(serializer.serialize(e.error_dict), 'utf-8')
+ else:
+ result = unicode(e) + u'\n'
except Exception, e:
import traceback
result = u'Internal server error\n'
- traceback.print_exc() # TODO logging!
- response = u'ERROR '
+ log.exception(u'PyminDaemon.handle: unhandled exception')
if result is None:
- response += u'0\n'
+ response += u' 0\n'
else:
- response += u'%d\n%s' % (len(result), result)
- self.file.sendto(response, addr)
+ response += u' %d\n%s' % (len(result), result)
+ log.debug(u'PyminDaemon.handle: response %r to %r', response, addr)
+ self.file.sendto(response.encode('utf-8'), addr)
+
+ def handle_timer(self):
+ r"handle_timer() -> None :: Call handle_timer() on handlers."
+ self.dispatcher.root.handle_timer()
def run(self):
r"run() -> None :: Run the event loop (shortcut to loop())"
+ log.debug(u'PyminDaemon.loop()')
+ # Start the timer
+ self.handle_timer()
+ signal.alarm(self.timer)
+ # Loop
try:
return self.loop()
except eventloop.LoopInterruptedError, e:
+ log.debug(u'PyminDaemon.loop: interrupted')
pass
if __name__ == '__main__':
- @handler(u"Print all the arguments, return nothing.")
- def test_handler(*args):
- print 'test:', args
-
- @handler(u"Echo the message passed as argument.")
- def echo_handler(message):
- print 'echo:', message
- return message
-
- PyminDaemon(dict(test=test_handler, echo=echo_handler)).run()
+ logging.basicConfig(
+ level = logging.DEBUG,
+ format = '%(asctime)s %(levelname)-8s %(message)s',
+ datefmt = '%H:%M:%S',
+ )
+
+ class Scheme(formencode.Schema):
+ mod = formencode.validators.OneOf(['upper', 'lower'], if_empty='lower')
+ ip = formencode.validators.CIDR
+
+ class Root(dispatcher.Handler):
+ @handler(u"Print all the arguments, return nothing.")
+ def test(self, *args):
+ print 'test:', args
+ @handler(u"Echo the message passed as argument.")
+ def echo(self, message, mod=None, ip=None):
+ vals = Scheme.to_python(dict(mod=mod, ip=ip))
+ mod = vals['mod']
+ ip = vals['ip']
+ message = getattr(message, mod)()
+ print 'echo:', message
+ return message
+
+ PyminDaemon(Root()).run()
projects / software / pymin.git / blobdiff