Jupyter notebook log kernel execution and user based on http proxy header

log.diff

diff --git a/notebook/base/handlers.py b/notebook/base/handlers.py
index 743f7bac7..6d8f478cf 100755
--- a/notebook/base/handlers.py
+++ b/notebook/base/handlers.py
@@ -126,6 +126,8 @@ class AuthenticatedHandler(web.RequestHandler):
             self.force_clear_cookie(self.cookie_name)
 
     def get_current_user(self):
+        if "X-AUTH-USER" in self.request.headers:
+            return self.request.headers["X-AUTH-USER"]
         if self.login_handler is None:
             return 'anonymous'
         return self.login_handler.get_user(self)
diff --git a/notebook/services/kernels/handlers.py b/notebook/services/kernels/handlers.py
index bca99ce1b..887044d59 100644
--- a/notebook/services/kernels/handlers.py
+++ b/notebook/services/kernels/handlers.py
@@ -327,6 +327,9 @@ class ZMQChannelsHandler(AuthenticatedZMQStreamHandler):
         channel = getattr(stream, 'channel', None)
         msg_type = msg['header']['msg_type']
 
+        if msg_type == 'execute_input':
+            self.log.critical("TRAK: %s", json.dumps({'who': self.current_user, 'what': msg['content']['code']}))
+
         if channel == 'iopub' and msg_type == 'status' and msg['content'].get('execution_state') == 'idle':
             # reset rate limit counter on status=idle,
             # to avoid 'Run All' hitting limits prematurely.