OpenTelemetry Hands-On

OpenTelemetry setup showing its capabilities.

Using:

• Node.js
  • An example app to send traces, metrics and logs via OpenTelemetry SDK
• OpenTelemetry Collector
  • To receive metrics and logs
  • To export metrics to Prometheus and export logs to Loki
• Jaeger
  • To receive and visualize traces
• Prometheus - To gather metrics
• Grafana - To visualize metrics from Prometheus
• Loki - To visualize logs

URLs

• Jaeger - http://localhost:16686
• Prometheus - http://localhost:9090
• Grafana - http://localhost:3000
  • User: admin
  • Default password: admin
• Loki - http://localhost:3100

TODOs

• Decide whether to use Jaeger or OpenTelemetry Collector to collect traces, metrics and logs
  • If Jaeger: Find a way to export data sent to Jaeger to Prometheus for metrics and Loki for logs
  • If OpenTelemetry Collector: Find a way to export traces to Jaeger, metrics to Prometheus and logs to Loki

App Set Up

cd ./app

# Use the correct Node.js version defined in .nvmrc
nvm use

# Install the dependencies
npm install

Docker Compose Set Up

# Build the Docker Image in ./app
docker compose build

# Start the services
docker compose up -d

# Check the logs of the app
docker compose logs -f app
# ... or of the collector
docker compose logs -f otel-collector

Send requests to the app

# GET /rolldice
curl http://localhost:8080/rolldice

# GET /rollrick
curl http://localhost:8080/rollrick