pylibmc: add docs

Author: clutchski

Rakefile

@@ -33,6 +33,7 @@ end
 
 desc "build the docs"
 task :docs do
+  sh "pip install sphinx"
   Dir.chdir 'docs' do
     sh "make html"
   end

ddtrace/contrib/pylibmc/__init__.py

@@ -1,4 +1,16 @@
+"""
+To trace the pylibmc Memcached client, wrap its connections with the traced
+client::
 
-from .client import TracedClient # flake8: noqa
+    import pylibmc
+    from ddtrace import tracer
+
+    client = TracedClient(
+        client=pylibmc.Client(["localhost:11211"]),
+        tracer=tracer,
+        service="my-cache-cluster")
 
+    client.set("key", "value")
+"""
 
+from .client import TracedClient # flake8: noqa

ddtrace/contrib/pylibmc/client.py

@@ -7,6 +7,7 @@
 from wrapt import ObjectProxy
 
 # project
+import ddtrace
 from ddtrace.ext import AppTypes
 from ddtrace.ext import net
 from .addrs import parse_addresses
@@ -21,11 +22,11 @@ class TracedClient(ObjectProxy):
     _service = None
     _tracer = None
 
-    def __init__(self, client, tracer, service="memcached"):
+    def __init__(self, client, service="memcached", tracer=None):
         """ Create a traced client that wraps the given memcached client. """
         super(TracedClient, self).__init__(client)
         self._service = service
-        self._tracer = tracer
+        self._tracer = tracer or ddtrace.tracer  # default to the global client
 
         # attempt to collect the pool of urls this client talks to
         try:
@@ -45,7 +46,7 @@ def __init__(self, client, tracer, service="memcached"):
     def clone(self, *args, **kwargs):
         # rewrap new connections.
         cloned = self.__wrapped__.clone(*args, **kwargs)
-        return TracedClient(cloned, self._tracer, self._service)
+        return TracedClient(cloned, tracer=self._tracer, service=self._service)
 
     def get(self, *args, **kwargs):
         return self._trace("get", *args, **kwargs)

docs/index.rst

@@ -146,6 +146,11 @@ Postgres
 
 .. automodule:: ddtrace.contrib.psycopg
 
+Pylibmc
+~~~~~~~~
+
+.. automodule:: ddtrace.contrib.pylibmc
+
 Redis
 ~~~~~
 

tests/contrib/pylibmc/test.py

@@ -139,5 +139,5 @@ def _setup():
     tracer = Tracer()
     tracer.writer = DummyWriter()
 
-    client = TracedClient(raw_client, tracer, TEST_SERVICE)
+    client = TracedClient(raw_client, tracer=tracer, service=TEST_SERVICE)
     return client, tracer