requests: ensure that disabled tracing still works

Author: clutchski

ddtrace/contrib/requests/__init__.py

@@ -28,6 +28,6 @@
 required_modules = ['requests']
 
 with require_modules(required_modules) as missing_modules:
-     if not missing_modules:
-         from .patch import TracedSession, patch
-         __all__ = ['TracedSession', 'patch']
+    if not missing_modules:
+        from .patch import TracedSession, patch
+        __all__ = ['TracedSession', 'patch']

ddtrace/contrib/requests/patch.py

@@ -1,5 +1,8 @@
 
 
+# stdlib
+import logging
+
 # 3p
 import requests
 import wrapt
@@ -10,6 +13,9 @@
 from ddtrace.ext import http
 
 
+log = logging.getLogger(__name__)
+
+
 def patch():
     """ Monkeypatch the requests library to trace http calls. """
     wrapt.wrap_function_wrapper('requests', 'Session.request', _traced_request_func)
@@ -26,19 +32,23 @@ def _traced_request_func(func, instance, args, kwargs):
 
     # bail on the tracing if not enabled.
     if not tracer.enabled:
-        return wrapped(*args, **kwargs)
+        return func(*args, **kwargs)
 
     # FIXME[matt] be a bit less brittle here.
     method = kwargs.get('method') or args[0]
-    url    = kwargs.get('url') or args[1]
+    url = kwargs.get('url') or args[1]
 
     with tracer.trace("requests.request") as span:
         resp = None
         try:
             resp = func(*args, **kwargs)
             return resp
         finally:
-            _apply_tags(span, method, url, resp)
+
+            try:
+                _apply_tags(span, method, url, resp)
+            except Exception:
+                log.warn("error patching tags", exc_info=True)
 
 
 def _apply_tags(span, method, url, response):

tests/contrib/requests/test_requests.py

@@ -11,6 +11,16 @@
 
 class TestSession(object):
 
+    @staticmethod
+    def test_tracer_disabled():
+        # ensure all valid combinations of args / kwargs work
+        tracer, session = get_traced_session()
+        tracer.enabled = False
+        out = session.get('http://httpstat.us/200')
+        eq_(out.status_code, 200)
+        spans = tracer.writer.pop()
+        eq_(len(spans), 0)
+
     @staticmethod
     def test_args_kwargs():
         # ensure all valid combinations of args / kwargs work