Move DD code into its own directory (#6)

reference/ddtrace/contrib/mongoengine/__init__.py

@@ -0,0 +1,29 @@
+"""Instrument mongoengine to report MongoDB queries.
+
+``patch_all`` will automatically patch your mongoengine connect method to make it work.
+::
+
+    from ddtrace import Pin, patch
+    import mongoengine
+
+    # If not patched yet, you can patch mongoengine specifically
+    patch(mongoengine=True)
+
+    # At that point, mongoengine is instrumented with the default settings
+    mongoengine.connect('db', alias='default')
+
+    # Use a pin to specify metadata related to this client
+    client = mongoengine.connect('db', alias='master')
+    Pin.override(client, service="mongo-master")
+"""
+
+from ...utils.importlib import require_modules
+
+
+required_modules = ['mongoengine']
+
+with require_modules(required_modules) as missing_modules:
+    if not missing_modules:
+        from .patch import patch, trace_mongoengine
+
+        __all__ = ['patch', 'trace_mongoengine']

reference/ddtrace/contrib/mongoengine/patch.py

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+import mongoengine
+
+from .trace import WrappedConnect
+from ...utils.deprecation import deprecated
+
+# Original connect function
+_connect = mongoengine.connect
+
+
+def patch():
+    setattr(mongoengine, 'connect', WrappedConnect(_connect))
+
+
+def unpatch():
+    setattr(mongoengine, 'connect', _connect)
+
+
+@deprecated(message='Use patching instead (see the docs).', version='1.0.0')
+def trace_mongoengine(*args, **kwargs):
+    return _connect

reference/ddtrace/contrib/mongoengine/trace.py

@@ -0,0 +1,32 @@
+
+# 3p
+from ddtrace.vendor import wrapt
+
+# project
+import ddtrace
+from ddtrace.ext import mongo as mongox
+from ddtrace.contrib.pymongo.client import TracedMongoClient
+
+
+# TODO(Benjamin): we should instrument register_connection instead, because more generic
+# We should also extract the "alias" attribute and set it as a meta
+class WrappedConnect(wrapt.ObjectProxy):
+    """ WrappedConnect wraps mongoengines 'connect' function to ensure
+        that all returned connections are wrapped for tracing.
+    """
+
+    def __init__(self, connect):
+        super(WrappedConnect, self).__init__(connect)
+        ddtrace.Pin(service=mongox.SERVICE, tracer=ddtrace.tracer).onto(self)
+
+    def __call__(self, *args, **kwargs):
+        client = self.__wrapped__(*args, **kwargs)
+        pin = ddtrace.Pin.get_from(self)
+        if pin:
+            # mongoengine uses pymongo internally, so we can just piggyback on the
+            # existing pymongo integration and make sure that the connections it
+            # uses internally are traced.
+            client = TracedMongoClient(client)
+            ddtrace.Pin(service=pin.service, tracer=pin.tracer).onto(client)
+
+        return client