import asyncore
+import asynchat
+import collections
+import grp
import os
+import pwd
import signal
import logging
import sched
from ganeti import utils
from ganeti import constants
from ganeti import errors
+from ganeti import netutils
+
+
+_DEFAULT_RUN_USER = "root"
+_DEFAULT_RUN_GROUP = "root"
class SchedulerBreakout(Exception):
return False
+def FormatAddress(family, address):
+ """Format a client's address
+
+ @type family: integer
+ @param family: socket family (one of socket.AF_*)
+ @type address: family specific (usually tuple)
+ @param address: address, as reported by this class
+
+ """
+ if family == socket.AF_INET and len(address) == 2:
+ return "%s:%d" % address
+ elif family == socket.AF_UNIX and len(address) == 3:
+ return "pid=%s, uid=%s, gid=%s" % address
+ else:
+ return str(address)
+
+
+class AsyncStreamServer(GanetiBaseAsyncoreDispatcher):
+ """A stream server to use with asyncore.
+
+ Each request is accepted, and then dispatched to a separate asyncore
+ dispatcher to handle.
+
+ """
+
+ _REQUEST_QUEUE_SIZE = 5
+
+ def __init__(self, family, address):
+ """Constructor for AsyncUnixStreamSocket
+
+ @type family: integer
+ @param family: socket family (one of socket.AF_*)
+ @type address: address family dependent
+ @param address: address to bind the socket to
+
+ """
+ GanetiBaseAsyncoreDispatcher.__init__(self)
+ self.family = family
+ self.create_socket(self.family, socket.SOCK_STREAM)
+ self.set_reuse_addr()
+ self.bind(address)
+ self.listen(self._REQUEST_QUEUE_SIZE)
+
+ # this method is overriding an asyncore.dispatcher method
+ def handle_accept(self):
+ """Accept a new client connection.
+
+ Creates a new instance of the handler class, which will use asyncore to
+ serve the client.
+
+ """
+ accept_result = utils.IgnoreSignals(self.accept)
+ if accept_result is not None:
+ connected_socket, client_address = accept_result
+ if self.family == socket.AF_UNIX:
+ # override the client address, as for unix sockets nothing meaningful
+ # is passed in from accept anyway
+ client_address = netutils.GetSocketCredentials(connected_socket)
+ logging.info("Accepted connection from %s",
+ FormatAddress(self.family, client_address))
+ self.handle_connection(connected_socket, client_address)
+
+ def handle_connection(self, connected_socket, client_address):
+ """Handle an already accepted connection.
+
+ """
+ raise NotImplementedError
+
+
+class AsyncTerminatedMessageStream(asynchat.async_chat):
+ """A terminator separated message stream asyncore module.
+
+ Handles a stream connection receiving messages terminated by a defined
+ separator. For each complete message handle_message is called.
+
+ """
+ def __init__(self, connected_socket, peer_address, terminator, family,
+ unhandled_limit):
+ """AsyncTerminatedMessageStream constructor.
+
+ @type connected_socket: socket.socket
+ @param connected_socket: connected stream socket to receive messages from
+ @param peer_address: family-specific peer address
+ @type terminator: string
+ @param terminator: terminator separating messages in the stream
+ @type family: integer
+ @param family: socket family
+ @type unhandled_limit: integer or None
+ @param unhandled_limit: maximum unanswered messages
+
+ """
+ # python 2.4/2.5 uses conn=... while 2.6 has sock=... we have to cheat by
+ # using a positional argument rather than a keyword one.
+ asynchat.async_chat.__init__(self, connected_socket)
+ self.connected_socket = connected_socket
+ # on python 2.4 there is no "family" attribute for the socket class
+ # FIXME: when we move to python 2.5 or above remove the family parameter
+ #self.family = self.connected_socket.family
+ self.family = family
+ self.peer_address = peer_address
+ self.terminator = terminator
+ self.unhandled_limit = unhandled_limit
+ self.set_terminator(terminator)
+ self.ibuffer = []
+ self.receive_count = 0
+ self.send_count = 0
+ self.oqueue = collections.deque()
+ self.iqueue = collections.deque()
+
+ # this method is overriding an asynchat.async_chat method
+ def collect_incoming_data(self, data):
+ self.ibuffer.append(data)
+
+ def _can_handle_message(self):
+ return (self.unhandled_limit is None or
+ (self.receive_count < self.send_count + self.unhandled_limit) and
+ not self.iqueue)
+
+ # this method is overriding an asynchat.async_chat method
+ def found_terminator(self):
+ message = "".join(self.ibuffer)
+ self.ibuffer = []
+ message_id = self.receive_count
+ # We need to increase the receive_count after checking if the message can
+ # be handled, but before calling handle_message
+ can_handle = self._can_handle_message()
+ self.receive_count += 1
+ if can_handle:
+ self.handle_message(message, message_id)
+ else:
+ self.iqueue.append((message, message_id))
+
+ def handle_message(self, message, message_id):
+ """Handle a terminated message.
+
+ @type message: string
+ @param message: message to handle
+ @type message_id: integer
+ @param message_id: stream's message sequence number
+
+ """
+ pass
+ # TODO: move this method to raise NotImplementedError
+ # raise NotImplementedError
+
+ def send_message(self, message):
+ """Send a message to the remote peer. This function is thread-safe.
+
+ @type message: string
+ @param message: message to send, without the terminator
+
+ @warning: If calling this function from a thread different than the one
+ performing the main asyncore loop, remember that you have to wake that one
+ up.
+
+ """
+ # If we just append the message we received to the output queue, this
+ # function can be safely called by multiple threads at the same time, and
+ # we don't need locking, since deques are thread safe. handle_write in the
+ # asyncore thread will handle the next input message if there are any
+ # enqueued.
+ self.oqueue.append(message)
+
+ # this method is overriding an asyncore.dispatcher method
+ def readable(self):
+ # read from the socket if we can handle the next requests
+ return self._can_handle_message() and asynchat.async_chat.readable(self)
+
+ # this method is overriding an asyncore.dispatcher method
+ def writable(self):
+ # the output queue may become full just after we called writable. This only
+ # works if we know we'll have something else waking us up from the select,
+ # in such case, anyway.
+ return asynchat.async_chat.writable(self) or self.oqueue
+
+ # this method is overriding an asyncore.dispatcher method
+ def handle_write(self):
+ if self.oqueue:
+ # if we have data in the output queue, then send_message was called.
+ # this means we can process one more message from the input queue, if
+ # there are any.
+ data = self.oqueue.popleft()
+ self.push(data + self.terminator)
+ self.send_count += 1
+ if self.iqueue:
+ self.handle_message(*self.iqueue.popleft())
+ self.initiate_send()
+
+ def close_log(self):
+ logging.info("Closing connection from %s",
+ FormatAddress(self.family, self.peer_address))
+ self.close()
+
+ # this method is overriding an asyncore.dispatcher method
+ def handle_expt(self):
+ self.close_log()
+
+ # this method is overriding an asyncore.dispatcher method
+ def handle_error(self):
+ """Log an error in handling any request, and proceed.
+
+ """
+ logging.exception("Error while handling asyncore request")
+ self.close_log()
+
+
class AsyncUDPSocket(GanetiBaseAsyncoreDispatcher):
"""An improved asyncore udp socket.
"""
- def __init__(self):
+ def __init__(self, family):
"""Constructor for AsyncUDPSocket
"""
GanetiBaseAsyncoreDispatcher.__init__(self)
self._out_queue = []
- self.create_socket(socket.AF_INET, socket.SOCK_DGRAM)
+ self._family = family
+ self.create_socket(family, socket.SOCK_DGRAM)
# this method is overriding an asyncore.dispatcher method
def handle_connect(self):
# this method is overriding an asyncore.dispatcher method
def handle_read(self):
- payload, address = utils.IgnoreSignals(self.recvfrom,
- constants.MAX_UDP_DATA_SIZE)
- ip, port = address
- self.handle_datagram(payload, ip, port)
+ recv_result = utils.IgnoreSignals(self.recvfrom,
+ constants.MAX_UDP_DATA_SIZE)
+ if recv_result is not None:
+ payload, address = recv_result
+ if self._family == socket.AF_INET6:
+ # we ignore 'flow info' and 'scope id' as we don't need them
+ ip, port, _, _ = address
+ else:
+ ip, port = address
+
+ self.handle_datagram(payload, ip, port)
def handle_datagram(self, payload, ip, port):
"""Handle an already read udp datagram
return False
+class AsyncAwaker(GanetiBaseAsyncoreDispatcher):
+ """A way to notify the asyncore loop that something is going on.
+
+ If an asyncore daemon is multithreaded when a thread tries to push some data
+ to a socket, the main loop handling asynchronous requests might be sleeping
+ waiting on a select(). To avoid this it can create an instance of the
+ AsyncAwaker, which other threads can use to wake it up.
+
+ """
+ def __init__(self, signal_fn=None):
+ """Constructor for AsyncAwaker
+
+ @type signal_fn: function
+ @param signal_fn: function to call when awaken
+
+ """
+ GanetiBaseAsyncoreDispatcher.__init__(self)
+ assert signal_fn == None or callable(signal_fn)
+ (self.in_socket, self.out_socket) = socket.socketpair(socket.AF_UNIX,
+ socket.SOCK_STREAM)
+ self.in_socket.setblocking(0)
+ self.in_socket.shutdown(socket.SHUT_WR)
+ self.out_socket.shutdown(socket.SHUT_RD)
+ self.set_socket(self.in_socket)
+ self.need_signal = True
+ self.signal_fn = signal_fn
+ self.connected = True
+
+ # this method is overriding an asyncore.dispatcher method
+ def handle_read(self):
+ utils.IgnoreSignals(self.recv, 4096)
+ if self.signal_fn:
+ self.signal_fn()
+ self.need_signal = True
+
+ # this method is overriding an asyncore.dispatcher method
+ def close(self):
+ asyncore.dispatcher.close(self)
+ self.out_socket.close()
+
+ def signal(self):
+ """Signal the asyncore main loop.
+
+ Any data we send here will be ignored, but it will cause the select() call
+ to return.
+
+ """
+ # Yes, there is a race condition here. No, we don't care, at worst we're
+ # sending more than one wakeup token, which doesn't harm at all.
+ if self.need_signal:
+ self.need_signal = False
+ self.out_socket.send("\0")
+
+
class Mainloop(object):
"""Generic mainloop for daemons
def GenericMain(daemon_name, optionparser, dirs, check_fn, exec_fn,
- console_logging=False):
+ multithreaded=False, console_logging=False,
+ default_ssl_cert=None, default_ssl_key=None,
+ user=_DEFAULT_RUN_USER, group=_DEFAULT_RUN_GROUP):
"""Shared main function for daemons.
@type daemon_name: string
@type exec_fn: function which accepts (options, args)
@param exec_fn: function that's executed with the daemon's pid file held, and
runs the daemon itself.
+ @type multithreaded: bool
+ @param multithreaded: Whether the daemon uses threads
@type console_logging: boolean
@param console_logging: if True, the daemon will fall back to the system
console if logging fails
+ @type default_ssl_cert: string
+ @param default_ssl_cert: Default SSL certificate path
+ @type default_ssl_key: string
+ @param default_ssl_key: Default SSL key path
+ @param user: Default user to run as
+ @type user: string
+ @param group: Default group to run as
+ @type group: string
"""
optionparser.add_option("-f", "--foreground", dest="fork",
constants.SYSLOG_USAGE,
default=constants.SYSLOG_USAGE,
choices=["no", "yes", "only"])
+
if daemon_name in constants.DAEMONS_PORTS:
- # for networked daemons we also allow choosing the bind port and address.
- # by default we use the port provided by utils.GetDaemonPort, and bind to
- # 0.0.0.0 (which is represented by and empty bind address.
- port = utils.GetDaemonPort(daemon_name)
+ default_bind_address = constants.IP4_ADDRESS_ANY
+ default_port = netutils.GetDaemonPort(daemon_name)
+
+ # For networked daemons we allow choosing the port and bind address
optionparser.add_option("-p", "--port", dest="port",
- help="Network port (%s default)." % port,
- default=port, type="int")
+ help="Network port (default: %s)" % default_port,
+ default=default_port, type="int")
optionparser.add_option("-b", "--bind", dest="bind_address",
- help="Bind address",
- default="", metavar="ADDRESS")
+ help=("Bind address (default: %s)" %
+ default_bind_address),
+ default=default_bind_address, metavar="ADDRESS")
- if daemon_name in constants.DAEMONS_SSL:
- default_cert, default_key = constants.DAEMONS_SSL[daemon_name]
+ if default_ssl_key is not None and default_ssl_cert is not None:
optionparser.add_option("--no-ssl", dest="ssl",
help="Do not secure HTTP protocol with SSL",
default=True, action="store_false")
optionparser.add_option("-K", "--ssl-key", dest="ssl_key",
- help="SSL key",
- default=default_key, type="string")
+ help=("SSL key path (default: %s)" %
+ default_ssl_key),
+ default=default_ssl_key, type="string",
+ metavar="SSL_KEY_PATH")
optionparser.add_option("-C", "--ssl-cert", dest="ssl_cert",
- help="SSL certificate",
- default=default_cert, type="string")
+ help=("SSL certificate path (default: %s)" %
+ default_ssl_cert),
+ default=default_ssl_cert, type="string",
+ metavar="SSL_CERT_PATH")
- multithread = utils.no_fork = daemon_name in constants.MULTITHREADED_DAEMONS
+ # Disable the use of fork(2) if the daemon uses threads
+ utils.no_fork = multithreaded
options, args = optionparser.parse_args()
- if hasattr(options, 'ssl') and options.ssl:
- if not (options.ssl_cert and options.ssl_key):
- print >> sys.stderr, "Need key and certificate to use ssl"
- sys.exit(constants.EXIT_FAILURE)
- for fname in (options.ssl_cert, options.ssl_key):
- if not os.path.isfile(fname):
- print >> sys.stderr, "Need ssl file %s to run" % fname
+ if getattr(options, "ssl", False):
+ ssl_paths = {
+ "certificate": options.ssl_cert,
+ "key": options.ssl_key,
+ }
+
+ for name, path in ssl_paths.iteritems():
+ if not os.path.isfile(path):
+ print >> sys.stderr, "SSL %s file '%s' was not found" % (name, path)
sys.exit(constants.EXIT_FAILURE)
+ # TODO: By initiating http.HttpSslParams here we would only read the files
+ # once and have a proper validation (isfile returns False on directories)
+ # at the same time.
+
if check_fn is not None:
check_fn(options, args)
utils.EnsureDirs(dirs)
if options.fork:
+ try:
+ uid = pwd.getpwnam(user).pw_uid
+ gid = grp.getgrnam(group).gr_gid
+ except KeyError:
+ raise errors.ConfigurationError("User or group not existing on system:"
+ " %s:%s" % (user, group))
utils.CloseFDs()
- utils.Daemonize(logfile=constants.DAEMONS_LOGFILES[daemon_name])
+ utils.Daemonize(constants.DAEMONS_LOGFILES[daemon_name], uid, gid)
utils.WritePidFile(daemon_name)
try:
utils.SetupLogging(logfile=constants.DAEMONS_LOGFILES[daemon_name],
debug=options.debug,
stderr_logging=not options.fork,
- multithreaded=multithread,
+ multithreaded=multithreaded,
program=daemon_name,
syslog=options.syslog,
console_logging=console_logging)