fix(pylibmc): support client initialization using servers [backport 3.2]

ddtrace/contrib/internal/pylibmc/client.py

@@ -41,7 +41,7 @@ def __init__(self, client=None, service=memcached.SERVICE, tracer=None, *args, *
         if not isinstance(client, _Client):
             # We are in the patched situation, just pass down all arguments to the pylibmc.Client
             # Note that, in that case, client isn't a real client (just the first argument)
-            client = _Client(client, *args, **kwargs)
+            client = _Client(kwargs.get("servers", client), **{k: v for k, v in kwargs.items() if k != "servers"})
         else:
             log.warning(
                 "TracedClient instantiation is deprecated and will be remove "

releasenotes/notes/pylibmc-bug-fix-client-419c7912f54418b7.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    pylibmc: fixes an issue where using ``Client(server=[url])`` would throw the error ``__init__() got multiple values for argument 'servers'``

tests/contrib/pylibmc/test.py

@@ -371,6 +371,36 @@ def test_patch_unpatch(self):
         assert spans, spans
         assert len(spans) == 1
 
+    def test_client_with_servers_option(self):
+        """
+        A test to make sure we support using `servers`, ie: with pylibmc.Client(servers=[url])
+        """
+        url = "%s:%s" % (cfg["host"], cfg["port"])
+
+        patch()
+        client = pylibmc.Client(servers=[url])
+        assert client.addresses[0] is url
+        Pin.get_from(client)._clone(service=self.TEST_SERVICE, tracer=self.tracer).onto(client)
+        client.set("a", 1)
+        spans = self.pop_spans()
+        assert spans, spans
+        assert len(spans) == 1
+
+    def test_client_without_servers_option(self):
+        """
+        A test to make sure we support the most basic use case of calling pylibmc.Client([url])
+        """
+        url = "%s:%s" % (cfg["host"], cfg["port"])
+
+        patch()
+        client = pylibmc.Client([url])
+        assert client.addresses[0] is url
+        Pin.get_from(client)._clone(service=self.TEST_SERVICE, tracer=self.tracer).onto(client)
+        client.set("a", 1)
+        spans = self.pop_spans()
+        assert spans, spans
+        assert len(spans) == 1
+
 
 class TestPylibmcPatchSchematization(TestPylibmcPatchDefault):
     @TracerTestCase.run_in_subprocess(env_overrides=dict(DD_SERVICE="mysvc", DD_TRACE_SPAN_ATTRIBUTE_SCHEMA="v0"))