add tracing to server

Author: rick-c-goog

.vscode/launch.json

@@ -0,0 +1,14 @@
+{
+    "configurations": [
+        {
+            "name": "Kubernetes: Run/Debug",
+            "type": "cloudcode.kubernetes",
+            "request": "launch",
+            "skaffoldConfig": "${workspaceFolder}/step2/skaffold.yaml",
+            "watch": true,
+            "cleanUp": true,
+            "portForward": true,
+            "imageRegistry": "gcr.io/rick-chen-demo1"
+        }
+    ]
+}

step2/src/client/client.py

@@ -83,9 +83,9 @@ class UnexpectedResultError(Exception):
 # NOTE: SimpleSpanProcessor is for debugging use in general.
 # we use it here for a demonstration purpose.
 exporter = CloudTraceSpanExporter()
+trace.set_tracer_provider(TracerProvider())
 trace.get_tracer_provider().add_span_processor(SimpleSpanProcessor(exporter))
 propagate.set_global_textmap(CloudTraceFormatPropagator())
-trace.set_tracer_provider(TracerProvider())
 
 
 @app.route("/")

step2/src/loadgen/loadgen.py

@@ -77,12 +77,12 @@ def main():
     target = os.environ.get("CLIENT_ADDR", "0.0.0.0:8080")
 
     exporter = CloudTraceSpanExporter()
+    trace.set_tracer_provider(TracerProvider())
     trace.get_tracer_provider().add_span_processor(
         SimpleSpanProcessor(exporter)
     )
     tracer = trace.get_tracer(__name__)
     propagate.set_global_textmap(CloudTraceFormatPropagator())
-    trace.set_tracer_provider(TracerProvider())
 
     # connectivity check to client service
     healthz = f"http://{target}/_healthz"