node.js.md

order	label
1	Node.js

OpenTelemetry for Node.js

The Baselime Node.js OpenTelemetry SDK enables you to instrument your Node.js services with OpenTelemetry without the boilerplate of using the OpenTelemetry SDK directly.

This SDK uses OpenTelemetry for JavaScript and provides a layer that facilitates instrumenting your Node.js applications.

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Instrumentation

!!!info Is your application already instrumented with OpenTelemetry?

!ref icon="../../assets/images/logos/logo_open_telemetry.png" text="Configure endpoint and headers" !!!

Step 1: Install the SDKs

Install the Baselime Node.js OpenTelemetry SDK.

npm i --save \
  @baselime/node-opentelemetry \
  @opentelemetry/auto-instrumentations-node

Step 2: Initialise the tracer

Create a tracing.js file

const { BaselimeSDK } = require('@baselime/node-opentelemetry');
const { getNodeAutoInstrumentations } = require('@opentelemetry/auto-instrumentations-node');
import opentelemetry from '@opentelemetry/api';

const sdk = new BaselimeSDK({
  instrumentations: [
    getNodeAutoInstrumentations(),
  ],
});

sdk.start();

// Get tracer
const tracer = opentelemetry.trace.getTracer('example-basic-tracer-node');

//Create a span
const parentSpan = tracer.startSpan('main');
parentSpan.end();

// Create meter
const meter = opentelemetry.metrics.getMeter(
  'instrumentation-scope-name',
  'instrumentation-scope-version',
);

// Create a counter
const counter = meter.createCounter('my-counter');
counter.add(1);

// Create a gauge
const gauge = meter.createUpDownCounter('events.counter');
counter.add(1);

Step 3: Set the Baselime environment variables

Set the environment variables of your comntainer service to include the Baselime API Key and set the NODE_OPTIONS enviroment variable to preload the OpenTelemetry SDK into your application.

Key	Value	Description
BASELIME_KEY	your-api-key	Get this key from the Baselime console or the Baselime CLI
NODE_OPTIONS	-r ./src/tracing.js	Preloads the OpenTelemetry SDK at startup

Once these steps are completed, distributed traces from your Node.js container applications should be available in Baselime to query via the console or the Baselime CLI.

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Configuration

The BaselimeSDK class of the Baselime Node.js OpenTelemetry SDK takes the following configuration options.

Field	Type	Description
instrumentations	InstrumentationOption[]	An array of instrumentation options
baselimeKey	string (optional)	The Baselime API key
collectorUrl	string (optional)	The URL of the collector
service	string (optional)	The service name
namespace	string (optional)	The namespace