Skip to main content

Node.js, Elasticsearch and OpenTelemetry

note

Check out the source code on GitHub here.

Tracetest is a testing tool based on OpenTelemetry that allows you to test your distributed application. It allows you to use data from distributed traces generated by OpenTelemetry to validate and assert if your application has the desired behavior defined by your test definitions.

Elastic is a search, observability, and security platform. The company is famous for developing the ELK stack - ElasticSearch, Kibana, Beats and Logstash that is used by thousands of developers. Elastic offers a cloud platform, Elastic Cloud, as its commercial offering to enable observability across logs, application performance monitoring (APM), and infrastructure monitoring, real user monitoring (RUM) and synthetic monitoring.

Node.js App with Elasticsearch, OpenTelemetry and Tracetest​

This is a simple quick start on how to configure a Node.js app to use OpenTelemetry with Elastic and Tracetest for enhancing your E2E and integration tests with trace-based testing. The infrastructure will use Elastic APM and Elasticsearch as the trace data store and OpenTelemetry Collector to receive traces from the Node.js app and send them to Elasticsearch.

Prerequisites​

Tracetest Account:

Docker: Have Docker and Docker Compose installed on your machine.

Run This Quckstart Example​

The example below is provided as part of the Tracetest project. You can download and run the example by following these steps:

Clone the Tracetest project and go to the Elastic Node.js Quickstart:

git clone https://github.com/kubeshop/tracetest
cd tracetest/examples/tracetest-elasticapm-with-otel

Follow these instructions to run the quick start:

  1. Copy the .env.template file to .env.
  2. Fill out the TRACETEST_TOKEN and ENVIRONMENT_ID details by editing your .env file.
  3. Run docker compose run tracetest-run.
  4. Follow the links in the output to view the test results.

Follow along with the sections below for an in detail breakdown of what the example you just ran did and how it works.

Project Structure​

The project contains Tracetest Agent, Elastic APM server, Elasticsearch, OpenTelemetry Collector, and a Node.js app.

The docker-compose.yaml file in the root directory of the quick start runs the Node.js app, Elasticsearch, Elastic APM server, OpenTelemetry Collector, and the Tracetest Agent setup.

Configuring the Node.js App​

The Node.js app is a simple Express app, contained in the app.js file.

Configure the .env like shown below.

# Get the required information here: https://app.tracetest.io/retrieve-token

TRACETEST_TOKEN="<YOUR_TRACETEST_TOKEN>"
TRACETEST_ENVIRONMENT_ID="<YOUR_ENV_ID>"

# Password for the 'elastic' user (at least 6 characters)
ELASTIC_PASSWORD=changeme

# Password for the 'kibana_system' user (at least 6 characters)
KIBANA_PASSWORD=changeme

# Version of Elastic products
STACK_VERSION=8.6.0

# Set the cluster name
CLUSTER_NAME=docker-cluster

# Set to 'basic' or 'trial' to automatically start the 30-day trial
LICENSE=basic

# Port to expose Elasticsearch HTTP API to the host
ES_PORT=9200

# Port to expose Kibana to the host
KIBANA_PORT=5601

# Increase or decrease based on the available host memory (in bytes)
MEM_LIMIT=1073741824

# Project namespace (defaults to the current folder name if not set)
# COMPOSE_PROJECT_NAME=test

The OpenTelemetry tracing is contained in the tracing.otel.grpc.js or tracing.otel.http.js files. Traces will be sent to OpenTelemetry Collector and forwarded from there to Elastic.

Choosing the tracing.otel.grpc.js file will send traces to OpenTelemetry Collector's GRPC endpoint.

Enabling the tracer is done by preloading the trace file. As seen in the package.json.

"scripts": {
  "app-with-grpc-tracer": "node -r ./tracing.otel.grpc.js app.js",
},

Run the Node.js App, Elasticsearch, Elastic APM, OpenTelemetry Collector and Tracetest​

The docker-compose.yaml file also contains the Tracetest Agent, OpenTelemetry Collector, Elasticsearch, Kibana, and Elastic APM server.

To run everything including Tracetest tests, run this command:

docker compose run tracetest-run

This will:

  1. Start the Node.js app, the OpenTelemetry Collector, and send the traces to Elastic APM.
  2. Start the Tracetest Agent.
  3. Configure the Elastic tracing backend and create tests in your environment.
  4. Run the tests.

Learn More​

Feel free to check out our examples in GitHub and join our Slack Community for more info!