Pydev remote debugging support added.

Change-Id: I2649ba4be2b375b42bf16957dc685d970d0bcd7d
Implements: blueprint task-manager-debug

bin/trove-taskmanager

@@ -16,18 +16,24 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import eventlet
-eventlet.monkey_patch()
-
 import gettext
-import optparse
 import os
 import sys
 
+import eventlet
+
+from trove.common import cfg
+from oslo.config import cfg as openstack_cfg
+from trove.openstack.common import log as logging
+from trove.common import debug_utils
+
+# Apply whole eventlet.mankey_patch excluding 'thread' module.
+# Decision for 'thread' module patching will be made
+# after debug_utils setting up
+eventlet.monkey_patch(all=True, thread=False)
 
 gettext.install('trove', unicode=1)
 
-
 # If ../trove/__init__.py exists, add ../ to Python search path, so that
 # it will override what happens to be installed in /usr/(local/)lib/python...
 possible_topdir = os.path.normpath(os.path.join(os.path.abspath(sys.argv[0]),
@@ -36,13 +42,6 @@ possible_topdir = os.path.normpath(os.path.join(os.path.abspath(sys.argv[0]),
 if os.path.exists(os.path.join(possible_topdir, 'trove', '__init__.py')):
     sys.path.insert(0, possible_topdir)
 
-from trove.common import cfg
-from trove.common import rpc
-from oslo.config import cfg as openstack_cfg
-from trove.openstack.common import log as logging
-from trove.openstack.common import service
-from trove.db import get_db_api
-
 CONF = cfg.CONF
 CONF.register_opts([openstack_cfg.StrOpt('taskmanager_manager')])
 
@@ -50,6 +49,16 @@ if __name__ == '__main__':
     cfg.parse_args(sys.argv)
     logging.setup(None)
 
+    debug_utils.setup()
+
+    # Patch 'thread' module if debug is disabled
+    if not debug_utils.enabled():
+        eventlet.monkey_patch(thread=True)
+
+    from trove.common import rpc
+    from trove.openstack.common import service
+    from trove.db import get_db_api
+
     try:
         get_db_api().configure_db(CONF)
         server = rpc.RpcService(manager=CONF.taskmanager_manager)

etc/trove/trove-taskmanager.conf.sample

@@ -85,3 +85,18 @@ control_exchange=trove
 # ============ Logging information =============================
 #log_dir = /integration/report
 #log_file = trove-taskmanager.log
+
+# ============ PyDev remote dubugging =============================
+
+# Enable or disable pydev remote debugging.
+# There are three values allowed: 'disabled', 'enabled' and 'auto'
+# If value is 'auto' tries to connect to remote debugger server,
+# but in case of error continue running with disabled debugging
+pydev_debug = disabled
+
+# remote debug server host and port options
+#pydev_debug_host = localhost
+#pydev_debug_port = 5678
+
+# path to pydevd library. It will be used if pydevd is absent in sys.path
+#pydev_path = <path>

trove/common/debug_utils.py

@@ -0,0 +1,146 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4 Copyright 2011 OpenStack Foundation
+# 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.
+#
+
+"""Help utilities for debugging"""
+
+import sys
+
+from oslo.config import cfg
+
+from trove.openstack.common import log
+
+
+LOG = log.getLogger(__name__)
+CONF = cfg.CONF
+
+__debug_state = None
+
+pydev_debug_opts = [
+    cfg.StrOpt("pydev_debug",
+               choices=("disabled", "enabled", "auto"),
+               default="disabled",
+               help="Enable or disable pydev remote debugging. "
+                    "If value is 'auto' tries to connect to remote "
+                    "debugger server, but in case of error "
+                    "continue running with disabled debugging"),
+
+    cfg.StrOpt("pydev_debug_host",
+               help="pydev debug server host (localhost by default)"),
+
+    cfg.IntOpt("pydev_debug_port",
+               help="pydev debug server port (5678 by default)"),
+
+    cfg.StrOpt("pydev_path",
+               help="defines path to pydevd library, used if pydevd is "
+                    "not found in python sys.path")
+]
+
+CONF.register_opts(pydev_debug_opts)
+
+
+def setup():
+    """
+    Analyze configuration for pydev remote debugging and establish
+    connection to remote debugger service if needed
+
+    @return: True if remote debugging was enabled successfully,
+        otherwise - False
+    """
+
+    global __debug_state
+
+    if CONF.pydev_debug == "enabled":
+        __debug_state = __setup_remote_pydev_debug(
+            pydev_debug_host=CONF.pydev_debug_host,
+            pydev_debug_port=CONF.pydev_debug_port,
+            pydev_path=CONF.pydev_path)
+    elif CONF.pydev_debug == "auto":
+        __debug_state = __setup_remote_pydev_debug_safe(
+            pydev_debug_host=CONF.pydev_debug_host,
+            pydev_debug_port=CONF.pydev_debug_port,
+            pydev_path=CONF.pydev_path)
+    else:
+        __debug_state = False
+
+
+def enabled():
+    """
+    @return: True if connection to remote debugger established, otherwise False
+    """
+    assert __debug_state is not None, ("debug_utils are not initialized. "
+                                       "Please call setup() method first")
+    return __debug_state
+
+
+def __setup_remote_pydev_debug_safe(pydev_debug_host=None,
+                                    pydev_debug_port=5678, pydev_path=None):
+    """
+    Safe version of __setup_remote_pydev_debug method. In error case returns
+    False as result instead of Exception raising
+
+    @see: __setup_remote_pydev_debug
+    """
+
+    try:
+        return __setup_remote_pydev_debug(
+            pydev_debug_host=pydev_debug_host,
+            pydev_debug_port=pydev_debug_port,
+            pydev_path=pydev_path)
+    except Exception as e:
+        LOG.info("Cann't connect to remote debug server. Continue working in "
+                 "standard mode. Error: %s", e)
+        return False
+
+
+def __setup_remote_pydev_debug(pydev_debug_host=None, pydev_debug_port=None,
+                               pydev_path=None):
+    """
+    Method connects to remote debug server, and attach current thread trace
+    to debugger. Also thread.start_new_thread thread.start_new are patched to
+    enable debugging of new threads
+
+    @param pydev_debug_host: remote debug server host hame, 'localhost'
+        if not specified or None
+    @param pydev_debug_port: remote debug server port, 5678
+        if not specified or None
+    @param pydev_path: optional path to pydevd library, used it pydevd is not
+        found in python sys.path
+    @return: True if debugging initialized,
+        otherwise exception should be raised
+    """
+
+    if pydev_debug_port is None:
+        pydev_debug_port = 5678
+    try:
+        import pydevd
+        LOG.debug("pydevd module was imported from system path")
+    except ImportError:
+        LOG.debug("Cann't load pydevd module from system path. Try load it "
+                  "from pydev_path: %s", pydev_path)
+        assert pydev_path, "pydev_path is not set"
+        if pydev_path not in sys.path:
+            sys.path.append(pydev_path)
+        import pydevd
+        LOG.debug("pydevd module was imported from pydev_path: %s", pydev_path)
+    pydevd.settrace(
+        host=pydev_debug_host,
+        port=pydev_debug_port,
+        stdoutToServer=True,
+        stderrToServer=True,
+        trace_only_current_thread=False,
+        suspend=False,
+    )
+    return True