OpenTelemetry Collector Exporter for node with grpc

This module provides exporter for web and node to be used with opentelemetry-collector - last tested with version 0.25.0.

Installation

npm install --save @opentelemetry/exporter-otlp-grpc

Service Name

The OpenTelemetry Collector Exporter does not have a service name configuration. In order to set the service name, use the service.name resource attribute as prescribed in the OpenTelemetry Resource Semantic Conventions.

Traces in Node - GRPC

The OTLPTraceExporter in Node expects the URL to only be the hostname. It will not work with /v1/traces.

const { BasicTracerProvider, SimpleSpanProcessor } = require('@opentelemetry/sdk-trace-base');
const { OTLPTraceExporter } =  require('@opentelemetry/exporter-otlp-grpc');

const collectorOptions = {
  // url is optional and can be omitted - default is grpc://localhost:4317
  url: 'grpc://<collector-hostname>:<port>',
};

const provider = new BasicTracerProvider();
const exporter = new OTLPTraceExporter(collectorOptions);
provider.addSpanProcessor(new SimpleSpanProcessor(exporter));

provider.register();
['SIGINT', 'SIGTERM'].forEach(signal => {
  process.on(signal, () => provider.shutdown().catch(console.error));
});

By default, plaintext connection is used. In order to use TLS in Node.js, provide credentials option like so:

const fs = require('fs');
const grpc = require('@grpc/grpc-js');

const { BasicTracerProvider, SimpleSpanProcessor } = require('@opentelemetry/sdk-trace-base');
const { OTLPTraceExporter } =  require('@opentelemetry/exporter-otlp-grpc');

const collectorOptions = {
  // url is optional and can be omitted - default is grpc://localhost:4317
  url: 'grpc://<collector-hostname>:<port>',
  credentials: grpc.credentials.createSsl(),
};

const provider = new BasicTracerProvider();
const exporter = new OTLPTraceExporter(collectorOptions);
provider.addSpanProcessor(new SimpleSpanProcessor(exporter));

provider.register();
['SIGINT', 'SIGTERM'].forEach(signal => {
  process.on(signal, () => provider.shutdown().catch(console.error));
});

To use mutual authentication, pass to the createSsl() constructor:

  credentials: grpc.credentials.createSsl(
    fs.readFileSync('./ca.crt'),
    fs.readFileSync('./client.key'),
    fs.readFileSync('./client.crt')
  ),

To generate credentials for mutual authentication, you can refer to the script used to generate certificates for tests here

The exporter can be configured to send custom metadata with each request as in the example below:

const grpc = require('@grpc/grpc-js');

const { BasicTracerProvider, SimpleSpanProcessor } = require('@opentelemetry/sdk-trace-base');
const { OTLPTraceExporter } =  require('@opentelemetry/exporter-otlp-grpc');

const metadata = new grpc.Metadata();
// For instance, an API key or access token might go here.
metadata.set('k', 'v');

const collectorOptions = {
  // url is optional and can be omitted - default is grpc://localhost:4317
  url: 'grpc://<collector-hostname>:<port>',
  metadata, // // an optional grpc.Metadata object to be sent with each request
};

const provider = new BasicTracerProvider();
const exporter = new OTLPTraceExporter(collectorOptions);
provider.addSpanProcessor(new SimpleSpanProcessor(exporter));

provider.register();
['SIGINT', 'SIGTERM'].forEach(signal => {
  process.on(signal, () => provider.shutdown().catch(console.error));
});

Note, that this will only work if TLS is also configured on the server.

Metrics in Node - GRPC

The OTLPTraceExporter in Node expects the URL to only be the hostname. It will not work with /v1/metrics. All options that work with trace also work with metrics.

const { MeterProvider } = require('@opentelemetry/sdk-metrics-base');
const { OTLPMetricExporter } =  require('@opentelemetry/exporter-otlp-grpc');
const collectorOptions = {
  // url is optional and can be omitted - default is grpc://localhost:4317
  url: 'grpc://<collector-hostname>:<port>',
};
const exporter = new OTLPMetricExporter(collectorOptions);

// Register the exporter
const provider = new MeterProvider({
  exporter,
  interval: 60000,
})
['SIGINT', 'SIGTERM'].forEach(signal => {
  process.on(signal, () => provider.shutdown().catch(console.error));
});

// Now, start recording data
const meter = provider.getMeter('example-meter');
const counter = meter.createCounter('metric_name');
counter.add(10, { 'key': 'value' });

Running opentelemetry-collector locally to see the traces

1. Go to examples/otlp-exporter-node
2. run npm run docker:start
3. Open page at http://localhost:9411/zipkin/ to observe the traces

Useful links

• For more information on OpenTelemetry, visit: https://opentelemetry.io/
• For more about OpenTelemetry JavaScript: https://github.com/open-telemetry/opentelemetry-js
• For help or feedback on this project, join us in GitHub Discussions

License

Apache 2.0 - See LICENSE for more information.