Backport PR #5486: disambiguate to location when no IPs can be determined

previously, fallback was to localhost, which could often be wrong.

closes  #5477

IPython/parallel/util.py

@@ -1,380 +1,390
-"""Some generic utilities for dealing with classes, urls, and serialization.
+"""Some generic utilities for dealing with classes, urls, and serialization."""
 
-Authors:
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
 
-* Min RK
-"""
-#-----------------------------------------------------------------------------
-#  Copyright (C) 2010-2011  The IPython Development Team
-#
-#  Distributed under the terms of the BSD License.  The full license is in
-#  the file COPYING, distributed as part of this software.
-#-----------------------------------------------------------------------------
-
-#-----------------------------------------------------------------------------
-# Imports
-#-----------------------------------------------------------------------------
-
-# Standard library imports.
 import logging
 import os
 import re
 import stat
 import socket
 import sys
+import warnings
 from signal import signal, SIGINT, SIGABRT, SIGTERM
 try:
     from signal import SIGKILL
 except ImportError:
     SIGKILL=None
 from types import FunctionType
 
 try:
     import cPickle
     pickle = cPickle
 except:
     cPickle = None
     import pickle
 
-# System library imports
 import zmq
 from zmq.log import handlers
 
 from IPython.external.decorator import decorator
 
-# IPython imports
 from IPython.config.application import Application
 from IPython.utils.localinterfaces import localhost, is_public_ip, public_ips
 from IPython.utils.py3compat import string_types, iteritems, itervalues
 from IPython.kernel.zmq.log import EnginePUBHandler
 from IPython.kernel.zmq.serialize import (
     unserialize_object, serialize_object, pack_apply_message, unpack_apply_message
 )
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 
 class Namespace(dict):
     """Subclass of dict for attribute access to keys."""
     
     def __getattr__(self, key):
         """getattr aliased to getitem"""
         if key in self:
             return self[key]
         else:
             raise NameError(key)
 
     def __setattr__(self, key, value):
         """setattr aliased to setitem, with strict"""
         if hasattr(dict, key):
             raise KeyError("Cannot override dict keys %r"%key)
         self[key] = value
     
 
 class ReverseDict(dict):
     """simple double-keyed subset of dict methods."""
     
     def __init__(self, *args, **kwargs):
         dict.__init__(self, *args, **kwargs)
         self._reverse = dict()
         for key, value in iteritems(self):
             self._reverse[value] = key
     
     def __getitem__(self, key):
         try:
             return dict.__getitem__(self, key)
         except KeyError:
             return self._reverse[key]
     
     def __setitem__(self, key, value):
         if key in self._reverse:
             raise KeyError("Can't have key %r on both sides!"%key)
         dict.__setitem__(self, key, value)
         self._reverse[value] = key
     
     def pop(self, key):
         value = dict.pop(self, key)
         self._reverse.pop(value)
         return value
     
     def get(self, key, default=None):
         try:
             return self[key]
         except KeyError:
             return default
 
 #-----------------------------------------------------------------------------
 # Functions
 #-----------------------------------------------------------------------------
 
 @decorator
 def log_errors(f, self, *args, **kwargs):
     """decorator to log unhandled exceptions raised in a method.
     
     For use wrapping on_recv callbacks, so that exceptions
     do not cause the stream to be closed.
     """
     try:
         return f(self, *args, **kwargs)
     except Exception:
         self.log.error("Uncaught exception in %r" % f, exc_info=True)
     
 
 def is_url(url):
     """boolean check for whether a string is a zmq url"""
     if '://' not in url:
         return False
     proto, addr = url.split('://', 1)
     if proto.lower() not in ['tcp','pgm','epgm','ipc','inproc']:
         return False
     return True
 
 def validate_url(url):
     """validate a url for zeromq"""
     if not isinstance(url, string_types):
         raise TypeError("url must be a string, not %r"%type(url))
     url = url.lower()
     
     proto_addr = url.split('://')
     assert len(proto_addr) == 2, 'Invalid url: %r'%url
     proto, addr = proto_addr
     assert proto in ['tcp','pgm','epgm','ipc','inproc'], "Invalid protocol: %r"%proto
     
     # domain pattern adapted from http://www.regexlib.com/REDetails.aspx?regexp_id=391
     # author: Remi Sabourin
     pat = re.compile(r'^([\w\d]([\w\d\-]{0,61}[\w\d])?\.)*[\w\d]([\w\d\-]{0,61}[\w\d])?$')
     
     if proto == 'tcp':
         lis = addr.split(':')
         assert len(lis) == 2, 'Invalid url: %r'%url
         addr,s_port = lis
         try:
             port = int(s_port)
         except ValueError:
             raise AssertionError("Invalid port %r in url: %r"%(port, url))
         
         assert addr == '*' or pat.match(addr) is not None, 'Invalid url: %r'%url
         
     else:
         # only validate tcp urls currently
         pass
     
     return True
 
 
 def validate_url_container(container):
     """validate a potentially nested collection of urls."""
     if isinstance(container, string_types):
         url = container
         return validate_url(url)
     elif isinstance(container, dict):
         container = itervalues(container)
     
     for element in container:
         validate_url_container(element)
 
 
 def split_url(url):
     """split a zmq url (tcp://ip:port) into ('tcp','ip','port')."""
     proto_addr = url.split('://')
     assert len(proto_addr) == 2, 'Invalid url: %r'%url
     proto, addr = proto_addr
     lis = addr.split(':')
     assert len(lis) == 2, 'Invalid url: %r'%url
     addr,s_port = lis
     return proto,addr,s_port
-    
+
+
 def disambiguate_ip_address(ip, location=None):
-    """turn multi-ip interfaces '0.0.0.0' and '*' into connectable
-    ones, based on the location (default interpretation of location is localhost)."""
-    if ip in ('0.0.0.0', '*'):
-        if location is None or is_public_ip(location) or not public_ips():
-            # If location is unspecified or cannot be determined, assume local
+    """turn multi-ip interfaces '0.0.0.0' and '*' into a connectable address
+    
+    Explicit IP addresses are returned unmodified.
+    
+    Parameters
+    ----------
+    
+    ip : IP address
+        An IP address, or the special values 0.0.0.0, or *
+    location: IP address, optional
+        A public IP of the target machine.
+        If location is an IP of the current machine,
+        localhost will be returned,
+        otherwise location will be returned.
+    """
+    if ip in {'0.0.0.0', '*'}:
+        if not location:
+            # unspecified location, localhost is the only choice
+            ip = localhost()
+        elif is_public_ip(location):
+            # location is a public IP on this machine, use localhost
             ip = localhost()
-        elif location:
-            return location
+        elif not public_ips():
+            # this machine's public IPs cannot be determined,
+            # assume `location` is not this machine
+            warnings.warn("IPython could not determine public IPs", RuntimeWarning)
+            ip = location
+        else:
+            # location is not this machine, do not use loopback
+            ip = location
     return ip
 
+
 def disambiguate_url(url, location=None):
     """turn multi-ip interfaces '0.0.0.0' and '*' into connectable
     ones, based on the location (default interpretation is localhost).
     
     This is for zeromq urls, such as ``tcp://*:10101``.
     """
     try:
         proto,ip,port = split_url(url)
     except AssertionError:
         # probably not tcp url; could be ipc, etc.
         return url
     
     ip = disambiguate_ip_address(ip,location)
     
     return "%s://%s:%s"%(proto,ip,port)
 
 
 #--------------------------------------------------------------------------
 # helpers for implementing old MEC API via view.apply
 #--------------------------------------------------------------------------
 
 def interactive(f):
     """decorator for making functions appear as interactively defined.
     This results in the function being linked to the user_ns as globals()
     instead of the module globals().
     """
     
     # build new FunctionType, so it can have the right globals
     # interactive functions never have closures, that's kind of the point
     if isinstance(f, FunctionType):
         mainmod = __import__('__main__')
         f = FunctionType(f.__code__, mainmod.__dict__,
             f.__name__, f.__defaults__,
         )
     # associate with __main__ for uncanning
     f.__module__ = '__main__'
     return f
 
 @interactive
 def _push(**ns):
     """helper method for implementing `client.push` via `client.apply`"""
     user_ns = globals()
     tmp = '_IP_PUSH_TMP_'
     while tmp in user_ns:
         tmp = tmp + '_'
     try:
         for name, value in ns.items():
             user_ns[tmp] = value
             exec("%s = %s" % (name, tmp), user_ns)
     finally:
         user_ns.pop(tmp, None)
 
 @interactive
 def _pull(keys):
     """helper method for implementing `client.pull` via `client.apply`"""
     if isinstance(keys, (list,tuple, set)):
         return [eval(key, globals()) for key in keys]
     else:
         return eval(keys, globals())
 
 @interactive
 def _execute(code):
     """helper method for implementing `client.execute` via `client.apply`"""
     exec(code, globals())
 
 #--------------------------------------------------------------------------
 # extra process management utilities
 #--------------------------------------------------------------------------
 
 _random_ports = set()
 
 def select_random_ports(n):
     """Selects and return n random ports that are available."""
     ports = []
     for i in range(n):
         sock = socket.socket()
         sock.bind(('', 0))
         while sock.getsockname()[1] in _random_ports:
             sock.close()
             sock = socket.socket()
             sock.bind(('', 0))
         ports.append(sock)
     for i, sock in enumerate(ports):
         port = sock.getsockname()[1]
         sock.close()
         ports[i] = port
         _random_ports.add(port)
     return ports
 
 def signal_children(children):
     """Relay interupt/term signals to children, for more solid process cleanup."""
     def terminate_children(sig, frame):
         log = Application.instance().log
         log.critical("Got signal %i, terminating children..."%sig)
         for child in children:
             child.terminate()
         
         sys.exit(sig != SIGINT)
         # sys.exit(sig)
     for sig in (SIGINT, SIGABRT, SIGTERM):
         signal(sig, terminate_children)
 
 def generate_exec_key(keyfile):
     import uuid
     newkey = str(uuid.uuid4())
     with open(keyfile, 'w') as f:
         # f.write('ipython-key ')
         f.write(newkey+'\n')
     # set user-only RW permissions (0600)
     # this will have no effect on Windows
     os.chmod(keyfile, stat.S_IRUSR|stat.S_IWUSR)
 
 
 def integer_loglevel(loglevel):
     try:
         loglevel = int(loglevel)
     except ValueError:
         if isinstance(loglevel, str):
             loglevel = getattr(logging, loglevel)
     return loglevel
 
 def connect_logger(logname, context, iface, root="ip", loglevel=logging.DEBUG):
     logger = logging.getLogger(logname)
     if any([isinstance(h, handlers.PUBHandler) for h in logger.handlers]):
         # don't add a second PUBHandler
         return
     loglevel = integer_loglevel(loglevel)
     lsock = context.socket(zmq.PUB)
     lsock.connect(iface)
     handler = handlers.PUBHandler(lsock)
     handler.setLevel(loglevel)
     handler.root_topic = root
     logger.addHandler(handler)
     logger.setLevel(loglevel)
 
 def connect_engine_logger(context, iface, engine, loglevel=logging.DEBUG):
     logger = logging.getLogger()
     if any([isinstance(h, handlers.PUBHandler) for h in logger.handlers]):
         # don't add a second PUBHandler
         return
     loglevel = integer_loglevel(loglevel)
     lsock = context.socket(zmq.PUB)
     lsock.connect(iface)
     handler = EnginePUBHandler(engine, lsock)
     handler.setLevel(loglevel)
     logger.addHandler(handler)
     logger.setLevel(loglevel)
     return logger
 
 def local_logger(logname, loglevel=logging.DEBUG):
     loglevel = integer_loglevel(loglevel)
     logger = logging.getLogger(logname)
     if any([isinstance(h, logging.StreamHandler) for h in logger.handlers]):
         # don't add a second StreamHandler
         return
     handler = logging.StreamHandler()
     handler.setLevel(loglevel)
     formatter = logging.Formatter("%(asctime)s.%(msecs).03d [%(name)s] %(message)s",
                 datefmt="%Y-%m-%d %H:%M:%S")
     handler.setFormatter(formatter)
 
     logger.addHandler(handler)
     logger.setLevel(loglevel)
     return logger
 
 def set_hwm(sock, hwm=0):
     """set zmq High Water Mark on a socket
     
     in a way that always works for various pyzmq / libzmq versions.
     """
     import zmq
     
     for key in ('HWM', 'SNDHWM', 'RCVHWM'):
         opt = getattr(zmq, key, None)
         if opt is None:
             continue
         try:
             sock.setsockopt(opt, hwm)
         except zmq.ZMQError:
             pass
 
         
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