From 01c6bcd9e436831d130964c1d7e5d5922bf5ecea Mon Sep 17 00:00:00 2001
From: John Bresnahan <jbresnah@redhat.com>
Date: Sat, 29 Dec 2012 05:54:56 -1000
Subject: [PATCH] Adding a means for a glance worker to connect back to a
 pydevd debugger.

That patch allows a developer to remotely run a pydev debugger and a
glance worker process connect back to it.  Two configuration options
have been added:
    pydev_worker_debug_host <host>. Default is None
    pydev_worker_debug_port <port>. Default is 5678
The behavior is enabled if pydev_worker_debug_host is not None.  If
a pydev connection fails to be esstablished an exception is raised.

This patch will allow remote debugging as well as more seemless
debugging environments with IDEs like pycharm.

Change-Id: I7d3f60e373632b256f0e914f18204ce223a3486e
---
 glance/common/config.py |  6 ++++++
 glance/common/utils.py  | 21 +++++++++++++++++++++
 glance/common/wsgi.py   |  5 +++++
 3 files changed, 32 insertions(+)

diff --git a/glance/common/config.py b/glance/common/config.py
index 53155cf0b2..921dcf660a 100644
--- a/glance/common/config.py
+++ b/glance/common/config.py
@@ -58,6 +58,12 @@ common_opts = [
                 help=_("Deploy the v1 OpenStack Images API. ")),
     cfg.BoolOpt('enable_v2_api', default=True,
                 help=_("Deploy the v2 OpenStack Images API. ")),
+    cfg.StrOpt('pydev_worker_debug_host', default=None,
+               help=_('The hostname/IP of the pydev process listening for '
+                      'debug connections')),
+    cfg.IntOpt('pydev_worker_debug_port', default=5678,
+               help=_('The port on which a pydev process is listening for '
+                      'connections.')),
 ]
 
 CONF = cfg.CONF
diff --git a/glance/common/utils.py b/glance/common/utils.py
index 9070883dd0..1500522d72 100644
--- a/glance/common/utils.py
+++ b/glance/common/utils.py
@@ -36,6 +36,7 @@ import sys
 from webob import exc
 
 from glance.common import exception
+from glance.openstack.common import cfg
 import glance.openstack.common.log as logging
 
 
@@ -410,3 +411,23 @@ def mutating(func):
                                     content_type="text/plain")
         return func(self, req, *args, **kwargs)
     return wrapped
+
+
+def setup_remote_pydev_debug(host, port):
+
+        error_msg = ('Error setting up the debug environment.  Verify that the'
+                     ' option pydev_worker_debug_port is pointing to a valid '
+                     'hostname or IP on which a pydev server is listening on'
+                     ' the port indicated by pydev_worker_debug_port.')
+
+        try:
+            from pydev import pydevd
+
+            pydevd.settrace(host,
+                            port=port,
+                            stdoutToServer=True,
+                            stderrToServer=True)
+            return True
+        except:
+            LOG.exception(error_msg)
+            raise
diff --git a/glance/common/wsgi.py b/glance/common/wsgi.py
index 7d5e0449a9..a62af7a0a7 100644
--- a/glance/common/wsgi.py
+++ b/glance/common/wsgi.py
@@ -40,6 +40,7 @@ import webob.dec
 import webob.exc
 
 from glance.common import exception
+from glance.common import utils
 from glance.openstack.common import cfg
 import glance.openstack.common.log as os_logging
 
@@ -266,6 +267,10 @@ class Server(object):
 
     def run_server(self):
         """Run a WSGI server."""
+        if cfg.CONF.pydev_worker_debug_host:
+            utils.setup_remote_pydev_debug(cfg.CONF.pydev_worker_debug_host,
+                                           cfg.CONF.pydev_worker_debug_port)
+
         eventlet.wsgi.HttpProtocol.default_request_version = "HTTP/1.0"
         try:
             eventlet.hubs.use_hub('poll')