Distributed tracing example

README.md

@@ -38,6 +38,12 @@ Create Python Virtual environment and run projec locally.
     flask run
     ```
 
+- Fire up another console and run second flask service locally
+
+    ```bash
+    python app1.py
+    ```
+
 ## Jaeger setup guidelines
 
 Run Jaeger container locally to collect tracing data from Flask application
@@ -48,12 +54,12 @@ docker run -p 16686:16686 -p 6831:6831/udp jaegertracing/all-in-one
 
 ## Demo
 
-Make sure you have Flask application running and jaeger running.
+Make sure you have Both Flask applications running and jaeger running.
 
 - Make GET requests to below APIs
 
     ```
-    localhost:5000
+    localhost:5000/hello
     localhost:5000/zero
     localhost:5000/zero-unhandled
     localhost:5000/zero-trace
@@ -67,3 +73,6 @@ Make sure you have Flask application running and jaeger running.
 
 - Notice the number of spans for each request. We can add more spans to each
 REST API for better detailed traces.
+
+- With first request, we can notice that it calls internally second service. As
+second service also have tracing enabled, we have more in-depth tracing information.

app.py

@@ -21,8 +21,15 @@
 )
 from opentelemetry.exporter.jaeger.thrift import JaegerExporter
 
+# propagator
+from opentelemetry.propagate import set_global_textmap
+from opentelemetry.propagators.b3 import B3Format
+
 load_dotenv()  # take environment variables from .env
 
+# Set global propagator
+set_global_textmap(B3Format())
+
 # set trace provider as default one
 trace.set_tracer_provider(
     TracerProvider(
@@ -52,13 +59,14 @@
 class HelloWorld(REST_Resource):
     def get(self):
         tracer = trace.get_tracer(__name__)
+        world = None
         with tracer.start_as_current_span("example-request"):
-            requests.get("http://www.example.com")
-        with tracer.start_as_current_span("get-oranges"):
+            data = requests.get("http://localhost:3000/get-hello")
+            world = data.json().get('hello')
+        with tracer.start_as_current_span("time-consuming-operation"):
             data = 100*100
             print("Hello World", data)
-        return {'hello': 'world'}
-
+        return {'hello': world}
 
 
 class ZeroDivision(REST_Resource):
@@ -83,7 +91,7 @@ def get(self):
         explode = 1/0
 
 
-api.add_resource(HelloWorld, '/')
+api.add_resource(HelloWorld, '/hello')
 api.add_resource(ZeroDivision, '/zero')
 api.add_resource(ZeroDivisionUnHandled, '/zero-unhandled')
 api.add_resource(ZeroDivisionZeroTrace, '/zero-trace')

app1.py

@@ -0,0 +1,79 @@
+__author__ = "Jay Modi"
+
+import os
+import requests
+
+from flask import Flask
+from flask_restful import Resource as REST_Resource, Api
+from dotenv import load_dotenv
+
+# opentelemetry
+from opentelemetry import trace
+from opentelemetry.trace.status import StatusCode
+from opentelemetry.sdk.resources import SERVICE_NAME, Resource
+from opentelemetry.sdk.trace import TracerProvider
+
+# flask and requests instrumentation
+from opentelemetry.instrumentation.flask import FlaskInstrumentor
+from opentelemetry.instrumentation.requests import RequestsInstrumentor
+
+# exporters
+from opentelemetry.sdk.trace.export import (
+    ConsoleSpanExporter,
+    SimpleSpanProcessor,
+    BatchSpanProcessor
+)
+from opentelemetry.exporter.jaeger.thrift import JaegerExporter
+
+# propagator
+from opentelemetry.propagate import set_global_textmap
+from opentelemetry.propagators.b3 import B3Format
+
+load_dotenv()  # take environment variables from .env
+
+# Set global propagator
+set_global_textmap(B3Format())
+
+# set trace provider as default one
+trace.set_tracer_provider(
+    TracerProvider(
+        resource=Resource.create({SERVICE_NAME: "my-other-service"})
+    )
+)
+
+# jaeger exporter
+jaeger_exporter = JaegerExporter(
+    agent_host_name="localhost",
+    agent_port=6831,
+)
+
+# add exporter to trace
+trace.get_tracer_provider().add_span_processor(
+    BatchSpanProcessor(jaeger_exporter)
+    # SimpleSpanProcessor(ConsoleSpanExporter)
+)
+
+app = Flask(__name__)
+api = Api(app)
+
+FlaskInstrumentor().instrument_app(app)
+RequestsInstrumentor().instrument()
+
+
+class GetHelloWorld(REST_Resource):
+    def get(self):
+        tracer = trace.get_tracer(__name__)
+        world = None
+        with tracer.start_as_current_span("get-hello-request"):
+            world = "World!"
+        return {'hello': world}
+
+
+api.add_resource(GetHelloWorld, '/get-hello')
+
+
+if __name__ == "__main__":
+    app.run(
+        debug=os.getenv("DEBUG"),
+        port=3000
+    )

requirements.txt

@@ -14,3 +14,6 @@ opentelemetry-instrumentation-requests==0.19b0
 
 # opentelemetry exporter
 opentelemetry-exporter-jaeger==1.0.0
+
+# opentelemetry propagator
+opentelemetry-propagator-b3==1.0.0