Add support to the Python Visual Studio Debugger

Change-Id: I1051656d61709c2f418e2fabdee2d16c889b7efd

doc/source/contributor/guides/remote-debugger.rst

@@ -16,7 +16,7 @@ Debugging Octavia code
 ======================
 
 This document describes how to setup and debug Octavia code using your favorite
-IDE (e.g. PyCharm).
+IDE (e.g. PyCharm, Visual Studio Code).
 
 Prerequisites
 =============
@@ -27,8 +27,10 @@ Prerequisites
 Setup
 =====
 
-Ensure your OpenStack and IDE environments have the PyDev library installed. If
-you're using PyCharm, you can find it in
+Ensure your OpenStack and IDE environments have the PyDev or ptvsd library
+installed.
+
+If you're using PyCharm, you can find it in
 */path/to/pycharm/debug-eggs/pycharm-debug.egg* (Python 2) and
 */path/to/pycharm/debug-eggs/pycharm-debug-py3k.egg* (Python 3). Copy that file
 into your OpenStack host and install the library in your Python path:
@@ -37,6 +39,11 @@ into your OpenStack host and install the library in your Python path:
 
     $ sudo easy_install pycharm-debug.egg
 
+If using Visual Studio Code, simply install ptvsd in both environments:
+
+::
+
+    $ pip install ptvsd
 
 Create a remote debugging configuration in your IDE. In PyCharm, go to *Run ->
 Edit Configurations -> Python Remote Debug*. The local host name refers to the
@@ -48,23 +55,25 @@ a path mapping in the remote debug configuration.
 Invoke the debug configuration (*Run -> Debug... -> (config name)*). PyCharm
 will begin listening on the specified host and port.
 
-Export *PYDEV_DEBUG_HOST* and *PYDEV_DEBUG_PORT* (host and port of the system
-running the IDE, respectively), and start the Octavia service you want to
-debug. It is recommended to run only one uWSGI process/controller worker.
-For example, to debug the Octavia Worker service:
+Export *DEBUGGER_TYPE*, *DEBUGGER_HOST* and *DEBUGGER_PORT* (host and port of
+the system running the IDE, respectively), and start the Octavia service you
+want to debug. It is recommended to run only one uWSGI process/controller
+worker. For example, to debug the Octavia Worker service:
 
 ::
 
-    $ export PYDEV_DEBUG_HOST=192.168.121.1
-    $ export PYDEV_DEBUG_PORT=5678
+    $ export DEBUGGER_TYPE=pydev
+    $ export DEBUGGER_HOST=192.168.121.1
+    $ export DEBUGGER_PORT=5678
     $ /usr/bin/octavia-worker --config-file /etc/octavia/octavia.conf
 
-Another example is the Octavia API service:
+Another example is debugging the Octavia API service with the ptvsd debugger:
 
 ::
 
-    $ export PYDEV_DEBUG_HOST=192.168.121.1
-    $ export PYDEV_DEBUG_PORT=5678
+    $ export DEBUGGER_TYPE=ptvsd
+    $ export DEBUGGER_HOST=192.168.121.1
+    $ export DEBUGGER_PORT=5678
     $ /usr/bin/uwsgi --ini /etc/octavia/octavia-uwsgi.ini -p 1
 
 The service will connect to your IDE, at which point remote debugging is

octavia/common/config.py

@@ -676,7 +676,7 @@ def init(args, **kwargs):
              version='%%prog %s' % version.version_info.release_string(),
              **kwargs)
     handle_deprecation_compatibility()
-    setup_remote_pydev_debug()
+    setup_remote_debugger()
 
 
 def setup_logging(conf):
@@ -708,32 +708,54 @@ def handle_deprecation_compatibility():
                              group='health_manager')
 
 
-def setup_remote_pydev_debug():
+def _enable_pydev(debugger_host, debugger_port):
+    try:
+        from pydev import pydevd
+    except ImportError:
+        import pydevd
+
+    pydevd.settrace(debugger_host,
+                    port=int(debugger_port),
+                    stdoutToServer=True,
+                    stderrToServer=True)
+
+
+def _enable_ptvsd(debuggger_host, debugger_port):
+    import ptvsd
+
+    # Allow other computers to attach to ptvsd at this IP address and port.
+    ptvsd.enable_attach(address=(debuggger_host, debugger_port),
+                        redirect_output=True)
+
+    # Pause the program until a remote debugger is attached
+    ptvsd.wait_for_attach()
+
+
+def setup_remote_debugger():
     """Required setup for remote debugging."""
 
-    pydev_debug_host = os.environ.get('PYDEV_DEBUG_HOST')
-    pydev_debug_port = os.environ.get('PYDEV_DEBUG_PORT')
+    debugger_type = os.environ.get('DEBUGGER_TYPE', 'pydev')
+    debugger_host = os.environ.get('DEBUGGER_HOST')
+    debugger_port = os.environ.get('DEBUGGER_PORT')
 
-    if not pydev_debug_host or not pydev_debug_port:
+    if not debugger_type or not debugger_host or not debugger_port:
         return
 
     try:
-        try:
-            from pydev import pydevd
-        except ImportError:
-            import pydevd
-
         LOG.warning("Connecting to remote debugger. Once connected, resume "
                     "the program on the debugger to continue with the "
                     "initialization of the service.")
-        pydevd.settrace(pydev_debug_host,
-                        port=int(pydev_debug_port),
-                        stdoutToServer=True,
-                        stderrToServer=True)
+        if debugger_type == 'pydev':
+            _enable_pydev(debugger_host, debugger_port)
+        elif debugger_type == 'ptvsd':
+            _enable_ptvsd(debugger_host, debugger_port)
+        else:
+            LOG.exception('Debugger %(debugger)s is not supported',
+                          debugger_type)
     except Exception:
         LOG.exception('Unable to join debugger, please make sure that the '
                       'debugger processes is listening on debug-host '
                       '\'%(debug-host)s\' debug-port \'%(debug-port)s\'.',
-                      {'debug-host': pydev_debug_host,
-                       'debug-port': pydev_debug_port})
+                      {'debug-host': debugger_host,
+                       'debug-port': debugger_port})
         raise

releasenotes/notes/add-ptvsd-debugger-33bb632bccf494bb.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Added support to debug with the Python Visual Studio Debugger engine
+    (ptvsd).