This is a sample app to demonstrate how to instrument NodeJS ExpressJS app with OpenTelemetry. It contains source code for the ExpressJS app which interacts with various services like Redis, MySQL, etc. to demonstrate tracing for these services. This repository has a docker compose file to set up all these services conveniently.
This repository is inentionally designed to work with any OpenTelemetry backend, not just CubeAPM. In fact, it can even work without any OpenTelemetry backend (by dumping traces to console, which is also the default behaviour).
Clone this repository and go to the project directory. Then run the following commands
npm install
docker compose up --build
ExpressJS app will now be available at http://localhost:8000.
The app has various API endpoints to demonstrate OpenTelemetry integrations with Redis, MySQL, etc. Check out app.js for the list of API endpoints. Hitting an API endpoint will generate the corresponding traces. Traces are printed to console (where docker compose is running) by default. If you want to send traces to a backend tool, comment out the OTEL_LOG_LEVEL line and uncomment the OTEL_EXPORTER_OTLP_TRACES_ENDPOINT line in docker-compose.yml.
The app can be run with the following command
OTEL_LOG_LEVEL=debug \
OTEL_SERVICE_NAME=cube_sample_nodejs_express \
NODE_OPTIONS="--require ./tracing.js" \
node app.js
Please feel free to raise PR for any enhancements - additional service integrations, library version updates, documentation updates, etc.