[pyramid] add DATADOG_PYRAMID_DISTRIBUTED_TRACING env var

ddtrace/contrib/pyramid/patch.py

@@ -1,7 +1,8 @@
 import os
 
 from .trace import trace_pyramid, DD_TWEEN_NAME
-from .constants import SETTINGS_SERVICE
+from .constants import SETTINGS_SERVICE, SETTINGS_DISTRIBUTED_TRACING
+from ...util import asbool
 
 import pyramid.config
 from pyramid.path import caller_package
@@ -24,8 +25,10 @@ def patch():
 def traced_init(wrapped, instance, args, kwargs):
     settings = kwargs.pop('settings', {})
     service = os.environ.get('DATADOG_SERVICE_NAME') or 'pyramid'
+    distributed_tracing = asbool(os.environ.get('DATADOG_PYRAMID_DISTRIBUTED_TRACING')) or False
     trace_settings = {
-        SETTINGS_SERVICE : service,
+        SETTINGS_SERVICE: service,
+        SETTINGS_DISTRIBUTED_TRACING: distributed_tracing,
     }
     settings.update(trace_settings)
     # If the tweens are explicitly set with 'pyramid.tweens', we need to

ddtrace/util.py

@@ -100,6 +100,18 @@ def _get_original_method(thing, key):
         setattr(patchable, key, dest.__get__(patchable, patchable.__class__))
 
 
+def asbool(value):
+    """Convert the given String to a boolean object. Accepted
+    values are `True` and `1`."""
+    if value is None:
+        return False
+
+    if isinstance(value, bool):
+        return value
+
+    return value.lower() in ("true", "1")
+
+
 def unwrap(obj, attr):
     f = getattr(obj, attr, None)
     if f and isinstance(f, wrapt.ObjectProxy) and hasattr(f, '__wrapped__'):

tests/contrib/pyramid/test_pyramid_autopatch.py

@@ -13,7 +13,7 @@
 from ...test_tracer import get_dummy_tracer
 from ...util import override_global_tracer
 
-from .test_pyramid import PyramidTestCase
+from .test_pyramid import PyramidTestCase, PyramidBase
 
 
 class TestPyramidAutopatch(PyramidTestCase):
@@ -29,6 +29,28 @@ def get_settings(self):
         }
 
 
+class TestPyramidDistributedTracing(PyramidBase):
+    instrument = False
+
+    def test_distributed_tracing(self):
+        # ensure the Context is properly created
+        # if distributed tracing is enabled
+        headers = {
+            'x-datadog-trace-id': '100',
+            'x-datadog-parent-id': '42',
+            'x-datadog-sampling-priority': '2',
+        }
+        res = self.app.get('/', headers=headers, status=200)
+        writer = self.tracer.writer
+        spans = writer.pop()
+        eq_(len(spans), 1)
+        # check the propagated Context
+        span = spans[0]
+        eq_(span.trace_id, 100)
+        eq_(span.parent_id, 42)
+        eq_(span.get_metric('_sampling_priority_v1'), 2)
+
+
 def _include_me(config):
     pass
 

tests/contrib/test_utils.py

@@ -1,6 +1,7 @@
 from nose.tools import eq_
 
 from ddtrace.contrib.util import func_name
+from ddtrace.util import asbool
 from functools import partial
 
 class SomethingCallable(object):

tests/test_utils.py

@@ -0,0 +1,19 @@
+import unittest
+
+from nose.tools import eq_
+
+from ddtrace.util import asbool
+
+
+class TestUtilities(unittest.TestCase):
+    def test_asbool(self):
+        # ensure the value is properly cast
+        eq_(asbool("True"), True)
+        eq_(asbool("true"), True)
+        eq_(asbool("1"), True)
+        eq_(asbool("False"), False)
+        eq_(asbool("false"), False)
+        eq_(asbool(None), False)
+        eq_(asbool(""), False)
+        eq_(asbool(True), True)
+        eq_(asbool(False), False)

tox.ini

@@ -322,6 +322,7 @@ setenv =
 [pyramid_autopatch]
 setenv =
     DATADOG_SERVICE_NAME = foobar
+    DATADOG_PYRAMID_DISTRIBUTED_TRACING = True
 
 [testenv:py27-pyramid-autopatch17-webtest]
 setenv =