opentracing_flask.py

from flask import Flask
from flask import request
import requests

from jaeger_client import Config
from flask_opentracing import FlaskTracer
import opentracing

app = Flask(__name__)

@app.route('/')
def pull_requests():

  # Fetch a list of pull requests on the opentracing repository
  github_url = "https://api.github.com/repos/opentracing/opentracing-python/pulls"

  parent_span = flask_tracer.get_span()
  with opentracing.tracer.start_span('github-api', child_of=parent_span) as span:
    span.set_tag("http.url",github_url)
    r = requests.get(github_url)
    span.set_tag("http.status_code", r.status_code)

  with opentracing.tracer.start_span('parse-json', child_of=parent_span) as span:
    json = r.json()
    span.set_tag("pull_requests", len(json))
    pull_request_titles = map(lambda item: item['title'], json)
  

  return 'OpenTracing Pull Requests: ' + ', '.join(pull_request_titles)


def initialize_tracer():
  config = Config(
      config={
          'sampler': {'type': 'const', 'param': 1}
      },
      service_name='hello-world')
  return config.initialize_tracer() # also sets opentracing.tracer



flask_tracer = FlaskTracer(initialize_tracer, True, app)