Prerequisite

SigNoz should be installed in your local machine or any server. To install SigNoz follow the instructions at https://signoz.io/docs/deployment/docker/

Simple Python Flask Program with MongoDB

To show how you can see metrics for External calls and DB calls in the Python app, we have created a sample app using a database (MongoDB) to make the example more realistic.

If you already have Mongo daemon running, you can skip the following step to install Mongo

Download MongoDB for:

• Mac from https://docs.mongodb.com/manual/tutorial/install-mongodb-on-os-x/
• Linux from https://docs.mongodb.com/manual/administration/install-on-linux/
• Ubuntu from https://docs.mongodb.com/manual/tutorial/install-mongodb-on-ubuntu/

Run instructions for sending data to SigNoz

• Create a virtual environment and activate it

python3 -m venv .venv
source .venv/bin/activate

• Install dependencies

pip install -r requirements.txt

• Install the instrumentation packages

opentelemetry-bootstrap --action=install

• Run the flask app

OTEL_RESOURCE_ATTRIBUTES=service.name=flaskApp OTEL_EXPORTER_OTLP_ENDPOINT=http://<IP of SigNoz>:4317 OTEL_EXPORTER_OTLP_PROTOCOL=grpc opentelemetry-instrument python3 app.py

<IP of SigNoz> will be localhost if you are running SigNoz in your localhost. For other installations you can use the same IP where SigNoz is accessible.

Note: set OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf and port 4318 in endpoint OTEL_EXPORTER_OTLP_ENDPOINT="http://<IP of SigNoz>:4318" if you are using OTLP HTTP exporter.

• Generate some traffic to the flask app

Our web server is running in the port 5002 by default. Browse http://localhost:5002 to send requests to this flask server and check the metrics and trace data at http://<IP of SigNoz>:3301

Troubleshooting

The reloader breaks instrumentation. To run instrumentation while the debug mode is enabled, set the use_reloader option to False:

if __name__ == "__main__":
    app.run(host='0.0.0.0', port=5002, debug=True, use_reloader=False)

If you face any problem in instrumenting with OpenTelemetry, refer to docs at https://signoz.io/docs/instrumentation/python

Run using Docker

1. Run MongoDB using below command:

docker run --rm --name my-mongo -it -dp 27017:27017 mongo:latest

2. Run sample-flask-app using docker image

docker run -e MONGO_HOST='IP_MONGO_HOST' -e OTEL_RESOURCE_ATTRIBUTES='service.name=pythonApp' -e OTEL_EXPORTER_OTLP_ENDPOINT='http://<IP of SigNoz>:4317' -dp 5002:5002 signoz/sample-flask-app:latest 

IP_MONGO_HOST will be host.docker.internal when running in localhost on Mac

Run using Docker-Compose

docker-compose up -d

Optional Build docker image

docker build --no-cache -t signoz/sample-flask-app:latest .