Running the OpenTelemetry demo application

Running the OpenTelemetry demo application locally

Clone the OpenTelemetry demo application repository.

git clone https://github.com/open-telemetry/opentelemetry-demo.git
cd opentelemetry-demo

Update the trace exporter to send to Splunk Observability.

Change src/otel-collector/otelcol-config-extras.yml

exporters:
  otlphttp/splunk:
    traces_endpoint: https://ingest.<Splunk_Observability_realm>.signalfx.com:443/v2/trace/otlp
    headers:
        "X-SF-Token": "<Splunk_Observability_access_token>"
        "Content-Type": "application/x-protobuf"

service:
  pipelines:
    traces:
        exporters: [spanmetrics, otlphttp/splunk]

Replace <Splunk_Observability_realm> with your Splunk Observability realm (e.g., us0, us1, eu0, etc.)
Replace <Splunk_Observability_access_token> with your Splunk Observability access token.

Start the OpenTelemetry demo application

docker compose up --force-recreate --remove-orphans --detach

Verify that the application is running by visiting http://localhost:8080 in your web browser. You should see the OpenTelemetry demo application homepage.

View a trace in Splunk Observability

Call a REST API of the OpenTelemetry demo application to generate some traces
- Firsty create a random traceparent. Example of traceparent header is 00-4bf92f3577b34da6a3ce929d0e0e4736-051581bf3cb55c14-01.
- Call a REST API
```
curl http://localhost:8080:8080/api/cart -H 'traceparent: <your-traceparent-ID>
```
  - example:
```
curl http://localhost:8080:8080/api/cart -H 'traceparent: 00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01'
```
Open the trace: https://app.us1.signalfx.com/#/apm/traces/4bf92f3577b34da6a3ce929d0e0e4736

Please note that it can take up to 5 minutes to see the trace in Splunk.

trace

Reverse proxy

We need to expose the OpenTelemetry demo application to the internet to be able create the ThousandEyes test. We can use a reverse proxy like ngrok to do this.

Configure ngrok

Sign up/log in at Ngrok.
Retrieve your authentication token from the ngrok Authtoken page.
Navigate to the ngrok Domains page and create a new domain. This ensures your domain remains static even after ngrok container restarts.
Example eternal-summary-hippo.ngrok-free.app

Add ngrok to the docker compose

Change opentelemetry-demo/docker-compose.yml

  ngrok:
    image: ngrok/ngrok
    container_name: ngrok
    command: ["http", "http://frontend-proxy:${ENVOY_PORT}", "--url=${NGROK_DOMAIN}", "--host-header=${NGROK_DOMAIN}"]
    restart: unless-stopped
    environment:
    - NGROK_AUTHTOKEN="${NGROK_AUTHTOKEN}"
    - ENVOY_PORT
    - NGROK_DOMAIN
    depends_on:
      frontend-proxy:
        condition: service_started
    logging: *logging

Change opentelemetry-demo/.env

Add the following variables:

NGROK_AUTHTOKEN=<your_ngrok_auth_token>
NGROK_DOMAIN=<your_ngrok_domain>

Example:

NGROK_AUTHTOKEN=21iZFQf5FYHou7VXd5yk1gOICI9_R46omx9uKSNnwSPiaH7N
NGROK_DOMAIN=eternal-summary-hippo.ngrok-free.app

Restart the OpenTelemetry demo application

docker compose up --force-recreate --remove-orphans --detach

View a trace in Splunk Observability

Call a REST API of the OpenTelemetry demo application to generate some traces.

curl <your_ngrok_domain>/api/cart -H 'traceparent: 00-1bf32f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01'

Example:

curl https://eternal-summary-hippo.ngrok-free.app/api/cart -H 'traceparent: 00-1bf32f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01'

Open the trace https://app.us1.signalfx.com/#/apm/traces/1bf32f3577b34da6a3ce929d0e0e4736.

trace