fastify-opentelemetry

OpenTelemetry API Connector for Fastify

fastify-opentelemetry is a plugin that connects your application with OpenTelemetry API for Fastify. It is built on top of the OpenTelemetry API for Javascript package.

If you want to connect to Stackdriver Trace API without using OpenTelemetry, please use fastify-gcloud-trace instead.

This plugin automatically instruments OpenTelemetry Tracing, and generates trace results. You can configure exporters and OpenTelemetry API plugins as you want. Please check out the detail here.

Here is an example of a trace result using Zipkin Trace Exporter:

Install

npm i fastify-opentelemetry

or

yarn add fastify-opentelemetry

Usage

There are two steps in using this plugin. First, you need to initialize the trace provider before the application code. You can find more details about how to initializise Open Telemetry SDK here.

tracer.js

const api = require('@opentelemetry/api');
const {NodeTracerProvider} = require('@opentelemetry/node');
const {SimpleSpanProcessor} = require('@opentelemetry/tracing');
const {ZipkinExporter} = require('@opentelemetry/exporter-zipkin');
 
module.exports = serviceName => {
  const provider = new NodeTracerProvider();
  provider.addSpanProcessor(
    new SimpleSpanProcessor(
      new ZipkinExporter({
        serviceName
      })
    )
  );
  provider.register();
  return api.trace.getTracer(serviceName);
};

Second, you need to import the tracer in your application code, and use the fastify-optentelemetry plugin in the following way.

server.js

const tracer = require('./preStart')('fastify');
const fastify = require('fastify');
fastify.register(fastifyOpentelemetry, {
  enabled: true,
  tracer
});

Options

This is the list of available options.

• enabled - If it is true, it generates a trace. The default value is true.
• tracer - OpenTelemetry API tracer object. This is a required property in order to use this plugin.
• ignoreUrls - You can pass an array of conditions to avoid creating a tracer for a certain URL. The conditions can be either string, regex, or function.
• ignoreMethods - Similar to ignoreUrls, you can pass an array of conditions to avoid creating a tracer for a certain request method.

Limitations

This is not an official plugin by OpenCensus for Fastify.

License Licensed under MIT.