Merge "Add eventlet backdoor to facilitate troubleshooting."

nova/common/eventlet_backdoor.py

@@ -0,0 +1,69 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright (c) 2012 Openstack, LLC.
+# 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.
+
+import gc
+import traceback
+
+import eventlet
+import eventlet.backdoor
+import greenlet
+
+from nova import flags
+from nova.openstack.common import cfg
+
+eventlet_backdoor_opts = [
+    cfg.IntOpt('backdoor_port',
+               default=None,
+               help='port for eventlet backdoor to listen')
+    ]
+
+FLAGS = flags.FLAGS
+FLAGS.register_opts(eventlet_backdoor_opts)
+
+
+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
+
+
+backdoor_locals = {
+    '_': None,                  # So it doesn't interfere with the global
+    '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,
+}
+
+
+def initialize_if_enabled():
+    if FLAGS.backdoor_port is None:
+        return
+
+    eventlet.spawn(eventlet.backdoor.backdoor_server,
+                   eventlet.listen(('localhost', FLAGS.backdoor_port)),
+                   locals=backdoor_locals)