GRPC minor fixes; GRPC test app & client (#180)

* Add message on instrumentation boot

* Add support for running the test server manually

* Add sample client code

Author: pglombardo

instana/instrumentation/grpcio.py

@@ -254,5 +254,6 @@ def call_behavior_with_instana(wrapped, instance, argv, kwargs):
             else:
                 return rv
 
+    logger.debug("Instrumenting grpcio")
 except ImportError:
     pass

tests/apps/grpc_server/stan_client.py

@@ -0,0 +1,54 @@
+from __future__ import absolute_import
+
+import time
+import random
+
+import grpc
+import stan_pb2
+import stan_pb2_grpc
+
+from instana.singletons import tracer
+
+testenv = dict()
+testenv["grpc_port"] = 10814
+testenv["grpc_host"] = "127.0.0.1"
+testenv["grpc_server"] = testenv["grpc_host"] + ":" + str(testenv["grpc_port"])
+
+
+def generate_questions():
+    """ Used in the streaming grpc tests """
+    questions = [
+        stan_pb2.QuestionRequest(question="Are you there?"),
+        stan_pb2.QuestionRequest(question="What time is it?"),
+        stan_pb2.QuestionRequest(question="Where in the world is Waldo?"),
+        stan_pb2.QuestionRequest(question="What did one campfire say to the other?"),
+        stan_pb2.QuestionRequest(question="Is cereal soup?"),
+        stan_pb2.QuestionRequest(question="What is always coming, but never arrives?")
+    ]
+    for q in questions:
+        yield q
+        time.sleep(random.uniform(0.2, 0.5))
+
+
+channel = grpc.insecure_channel(testenv["grpc_server"])
+server_stub = stan_pb2_grpc.StanStub(channel)
+# The grpc client apparently needs a second to connect and initialize
+time.sleep(1)
+
+with tracer.start_active_span('http-server') as scope:
+    scope.span.set_tag('http.url', 'https://localhost:8080/grpc-client')
+    scope.span.set_tag('http.method', 'GET')
+    scope.span.set_tag('span.kind', 'entry')
+    response = server_stub.OneQuestionOneResponse(stan_pb2.QuestionRequest(question="Are you there?"))
+
+with tracer.start_active_span('http-server') as scope:
+    scope.span.set_tag('http.url', 'https://localhost:8080/grpc-server-streaming')
+    scope.span.set_tag('http.method', 'GET')
+    scope.span.set_tag('span.kind', 'entry')
+    responses = server_stub.OneQuestionManyResponses(stan_pb2.QuestionRequest(question="Are you there?"))
+
+with tracer.start_active_span('http-server') as scope:
+    scope.span.set_tag('http.url', 'https://localhost:8080/grpc-client-streaming')
+    scope.span.set_tag('http.method', 'GET')
+    scope.span.set_tag('span.kind', 'entry')
+    response = server_stub.ManyQuestionsOneResponse(generate_questions())

tests/apps/grpc_server/stan_server.py

@@ -1,10 +1,16 @@
+import os
+import sys
 import grpc
 import time
 import tests.apps.grpc_server.stan_pb2 as stan_pb2
 import tests.apps.grpc_server.stan_pb2_grpc as stan_pb2_grpc
 from concurrent import futures
 
-from ...helpers import testenv
+try:
+    from ...helpers import testenv
+except ValueError:
+    # We must be running from the command line...
+    testenv = {}
 
 testenv["grpc_port"] = 10814
 testenv["grpc_host"] = "127.0.0.1"
@@ -80,3 +86,12 @@ def start_server(self):
             rpc_server.stop(0)
             print('Stan as a Service RPC Server Stopped ...')
 
+
+if __name__ == "__main__":
+    print ("Booting foreground GRPC application...")
+    # os.environ["INSTANA_TEST"] = "true"
+
+    if sys.version_info >= (3, 5, 3):
+        StanServicer().start_server()
+    else:
+        print("Python v3.5.3 or higher only")