docker-otel-lgtm

An OpenTelemetry backend in a Docker image.

The grafana/otel-lgtm Docker image is an open source backend for OpenTelemetry that’s intended for development, demo, and testing environments. If you are looking for a production-ready, out-of-the box solution to monitor applications and minimize MTTR (mean time to resolution) with OpenTelemetry and Prometheus, you should try Grafana Cloud Application Observability.

Documentation

• Blog post: An OpenTelemetry backend in a Docker image: Introducing grafana/otel-lgtm

Get the Docker image

The Docker image is available on Docker hub: https://hub.docker.com/r/grafana/otel-lgtm

Run the Docker image

# Unix/Linux
./run-lgtm.sh

# Windows (PowerShell)
./run-lgtm

Configuration

Enable logging

You can enable logging for troubleshooting:

Environment Variable	Enable Logging in
ENABLE_LOGS_GRAFANA	Grafana
ENABLE_LOGS_LOKI	Loki
ENABLE_LOGS_PROMETHEUS	Prometheus
ENABLE_LOGS_TEMPO	Tempo
ENABLE_LOGS_OTELCOL	OpenTelemetry Collector
ENABLE_LOGS_ALL	all of the above

This has nothing to do with the application logs, which are collected by OpenTelemetry.

Persist data across container instantiation

The various components in the repository are configured to write their data to the /data directory. If you need to persist data across containers being created and destroyed, you can mount a volume to the /data directory. Note that this image is intended for development, demo, and testing environments and persisting data to an external volume doesn't change that. However, this feature could be useful in certain cases for some users even in testing situations.

Run lgtm in kubernetes

# create k8s resources
kubectl apply -f k8s/lgtm.yaml

# port forwarding
kubectl port-forward service/lgtm 3000:3000 4317:4317 4318:4318

Send OpenTelemetry Data

There's no need to configure anything: The Docker image works with OpenTelemetry's defaults.

# Not needed as these are the defaults in OpenTelemetry:
export OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf
export OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318

View Grafana

Log in to http://localhost:3000 with user admin and password admin.

Build the Docker image from scratch

cd docker/
docker build . -t grafana/otel-lgtm

Build and run the example app

Run the example REST service:

# Unix/Linux
./run-example.sh

# Windows (PowerShell)
./run-example

Generate traffic:

# Unix/Linux
./generate-traffic.sh

# Windows (PowerShell)
./generate-traffic

Run example apps in different languages

The example apps are in the examples/ directory. Each example has a run.sh or run.cmd script to start the app.

Every example implements a rolldice service, which returns a random number between 1 and 6.

Each example uses a different application port (to be able to run all applications at the same time).

Example	Service URL
Java	curl http://localhost:8080/rolldice
Go	curl http://localhost:8081/rolldice
Python	curl http://localhost:8082/rolldice
dotnet	curl http://localhost:8083/rolldice

Related Work

• Metrics, Logs, Traces and Profiles in Grafana: https://github.com/grafana/intro-to-mltp