Catch exception when trying to write /proc/.../ip_forward in the config file.

[software/pymin.git] / pymin / pymindaemon.py

diff --git a/pymin/pymindaemon.py b/pymin/pymindaemon.py
index be2c9750d29339d7b79d696bdf6218898ed267c8..6f4fa736534147539873a93d2be8b5f3dcf3a635 100644 (file)
--- a/pymin/pymindaemon.py
+++ b/pymin/pymindaemon.py
@@ -10,91 +10,171 @@ command-line.
 
 import signal
 import socket
 
 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 eventloop
 from pymin import serializer

+from pymin import procman

 
 class PyminDaemon(eventloop.EventLoop):
 
 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).
 
 
     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:
 
 
     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.
         """
         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 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
         # 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
             # 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)
 
     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:
         try:

-            result = self.dispatcher.dispatch(msg)
+            result = self.dispatcher.dispatch(unicode(msg, 'utf-8'))

             if result is not None:
                 result = serializer.serialize(result)
             if result is not None:
                 result = serializer.serialize(result)

-            response = u'OK '
+            response = u'OK'

         except dispatcher.Error, e:
             result = unicode(e) + u'\n'
         except dispatcher.Error, e:
             result = unicode(e) + u'\n'

-            response = u'ERROR '
+        except formencode.Invalid, e:
+            if e.error_dict:
+                result = serializer.serialize(e.error_dict)
+            else:
+                result = unicode(e) + u'\n'

         except Exception, e:
             import traceback
             result = u'Internal server error\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:
         if result is None:

-            response += u'0\n'
+            response += u' 0\n'

         else:
         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())"
 
     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:
         try:
             return self.loop()
         except eventloop.LoopInterruptedError, e:

+            log.debug(u'PyminDaemon.loop: interrupted')

             pass
 
 if __name__ == '__main__':
 
             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()