1 files changed, 146 insertions, 0 deletions
diff --git a/keystone/openstack/common/eventlet_backdoor.py b/keystone/openstack/common/eventlet_backdoor.py
new file mode 100644
index 00000000..c4d18ddb
--- /dev/null
+++ b/keystone/openstack/common/eventlet_backdoor.py
@@ -0,0 +1,146 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright (c) 2012 OpenStack Foundation.
+# Administrator of the National Aeronautics and Space Administration.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from __future__ import print_function
+
+import errno
+import gc
+import os
+import pprint
+import socket
+import sys
+import traceback
+
+import eventlet
+import eventlet.backdoor
+import greenlet
+from oslo.config import cfg
+
+from keystone.openstack.common.gettextutils import _  # noqa
+from keystone.openstack.common import log as logging
+
+help_for_backdoor_port = (
+    "Acceptable values are 0, <port>, and <start>:<end>, where 0 results "
+    "in listening on a random tcp port number; <port> results in listening "
+    "on the specified port number (and not enabling backdoor if that port "
+    "is in use); and <start>:<end> results in listening on the smallest "
+    "unused port number within the specified range of port numbers.  The "
+    "chosen port is displayed in the service's log file.")
+eventlet_backdoor_opts = [
+    cfg.StrOpt('backdoor_port',
+               default=None,
+               help="Enable eventlet backdoor.  %s" % help_for_backdoor_port)
+]
+
+CONF = cfg.CONF
+CONF.register_opts(eventlet_backdoor_opts)
+LOG = logging.getLogger(__name__)
+
+
+class EventletBackdoorConfigValueError(Exception):
+    def __init__(self, port_range, help_msg, ex):
+        msg = ('Invalid backdoor_port configuration %(range)s: %(ex)s. '
+               '%(help)s' %
+               {'range': port_range, 'ex': ex, 'help': help_msg})
+        super(EventletBackdoorConfigValueError, self).__init__(msg)
+        self.port_range = port_range
+
+
+def _dont_use_this():
+    print("Don't use this, just disconnect instead")
+
+
+def _find_objects(t):
+    return filter(lambda o: isinstance(o, t), gc.get_objects())
+
+
+def _print_greenthreads():
+    for i, gt in enumerate(_find_objects(greenlet.greenlet)):
+        print(i, gt)
+        traceback.print_stack(gt.gr_frame)
+        print()
+
+
+def _print_nativethreads():
+    for threadId, stack in sys._current_frames().items():
+        print(threadId)
+        traceback.print_stack(stack)
+        print()
+
+
+def _parse_port_range(port_range):
+    if ':' not in port_range:
+        start, end = port_range, port_range
+    else:
+        start, end = port_range.split(':', 1)
+    try:
+        start, end = int(start), int(end)
+        if end < start:
+            raise ValueError
+        return start, end
+    except ValueError as ex:
+        raise EventletBackdoorConfigValueError(port_range, ex,
+                                               help_for_backdoor_port)
+
+
+def _listen(host, start_port, end_port, listen_func):
+    try_port = start_port
+    while True:
+        try:
+            return listen_func((host, try_port))
+        except socket.error as exc:
+            if (exc.errno != errno.EADDRINUSE or
+               try_port >= end_port):
+                raise
+            try_port += 1
+
+
+def initialize_if_enabled():
+    backdoor_locals = {
+        'exit': _dont_use_this,      # So we don't exit the entire process
+        'quit': _dont_use_this,      # So we don't exit the entire process
+        'fo': _find_objects,
+        'pgt': _print_greenthreads,
+        'pnt': _print_nativethreads,
+    }
+
+    if CONF.backdoor_port is None:
+        return None
+
+    start_port, end_port = _parse_port_range(str(CONF.backdoor_port))
+
+    # NOTE(johannes): The standard sys.displayhook will print the value of
+    # the last expression and set it to __builtin__._, which overwrites
+    # the __builtin__._ that gettext sets. Let's switch to using pprint
+    # since it won't interact poorly with gettext, and it's easier to
+    # read the output too.
+    def displayhook(val):
+        if val is not None:
+            pprint.pprint(val)
+    sys.displayhook = displayhook
+
+    sock = _listen('localhost', start_port, end_port, eventlet.listen)
+
+    # In the case of backdoor port being zero, a port number is assigned by
+    # listen().  In any case, pull the port number out here.
+    port = sock.getsockname()[1]
+    LOG.info(_('Eventlet backdoor listening on %(port)s for process %(pid)d') %
+             {'port': port, 'pid': os.getpid()})
+    eventlet.spawn_n(eventlet.backdoor.backdoor_server, sock,
+                     locals=backdoor_locals)
+    return port