flask_example.py

# Copyright The OpenTelemetry Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""
This module serves as an example to integrate with flask, using
the requests library to perform downstream requests
"""
import flask
import requests

import opentelemetry.instrumentation.requests
from opentelemetry import trace
from opentelemetry.instrumentation.flask import FlaskInstrumentor
from opentelemetry.sdk.trace import TracerProvider
from opentelemetry.sdk.trace.export import (
    ConsoleSpanExporter,
    SimpleExportSpanProcessor,
)

# The preferred tracer implementation must be set, as the opentelemetry-api
# defines the interface with a no-op implementation.
# It must be done before instrumenting any library
trace.set_tracer_provider(TracerProvider())

opentelemetry.instrumentation.requests.RequestsInstrumentor().instrument()

trace.get_tracer_provider().add_span_processor(
    SimpleExportSpanProcessor(ConsoleSpanExporter())
)

app = flask.Flask(__name__)

FlaskInstrumentor().instrument_app(app)


@app.route("/")
def hello():
    tracer = trace.get_tracer(__name__)
    with tracer.start_as_current_span("example-request"):
        requests.get("http://www.example.com")
    return "hello"