Add instrumentation dir with urllib3 instrumentation

Author: pglombardo

instana/instrumentation/__init__.py

@@ -0,0 +1,30 @@
+import opentracing.ext.tags as ext
+import opentracing
+import wrapt
+
+
+@wrapt.patch_function_wrapper('urllib3', 'PoolManager.urlopen')
+def urlopen_with_instana(wrapped, instance, args, kwargs):
+    try:
+        span = opentracing.global_tracer.start_span("urllib3")
+        span.set_tag(ext.HTTP_URL, args[1])
+        span.set_tag(ext.HTTP_METHOD, args[0])
+
+        opentracing.global_tracer.inject(span.context, opentracing.Format.HTTP_HEADERS, kwargs["headers"])
+
+        rv = wrapped(*args, **kwargs)
+        span.set_tag(ext.HTTP_STATUS_CODE, rv.status)
+        if 500 <= rv.status <= 511:
+            span.set_tag("error", True)
+            ec = span.tags.get('ec', 0)
+            span.set_tag("ec", ec+1)
+
+    except Exception as e:
+        print("found error:", e)
+        span.set_tag("error", True)
+        ec = span.tags.get('ec', 0)
+        span.set_tag("ec", ec+1)
+        raise
+    else:
+        span.finish()
+        return rv