What is @opentelemetry/instrumentation-fastify?
@opentelemetry/instrumentation-fastify is an npm package that provides automatic instrumentation for Fastify applications using OpenTelemetry. It helps in collecting and exporting telemetry data such as traces and metrics, which can be used for monitoring and performance analysis.
What are @opentelemetry/instrumentation-fastify's main functionalities?
Automatic Tracing
This code demonstrates how to set up automatic tracing for a Fastify application using @opentelemetry/instrumentation-fastify. It initializes the OpenTelemetry tracer provider and registers the Fastify instrumentation to automatically collect trace data for incoming requests.
const { NodeTracerProvider } = require('@opentelemetry/sdk-trace-node');
const { registerInstrumentations } = require('@opentelemetry/instrumentation');
const { FastifyInstrumentation } = require('@opentelemetry/instrumentation-fastify');
const provider = new NodeTracerProvider();
provider.register();
registerInstrumentations({
instrumentations: [
new FastifyInstrumentation()
],
tracerProvider: provider,
});
const fastify = require('fastify')();
fastify.get('/hello', async (request, reply) => {
return { hello: 'world' };
});
fastify.listen(3000, err => {
if (err) throw err;
console.log('Server listening on http://localhost:3000');
});
Custom Span Attributes
This code sample shows how to add custom attributes to spans in a Fastify application. The `requestHook` option allows you to modify the span for each request, adding custom attributes that can be useful for more detailed telemetry data.
const { NodeTracerProvider } = require('@opentelemetry/sdk-trace-node');
const { registerInstrumentations } = require('@opentelemetry/instrumentation');
const { FastifyInstrumentation } = require('@opentelemetry/instrumentation-fastify');
const provider = new NodeTracerProvider();
provider.register();
registerInstrumentations({
instrumentations: [
new FastifyInstrumentation({
requestHook: (span, request) => {
span.setAttribute('http.custom_attribute', 'custom_value');
}
})
],
tracerProvider: provider,
});
const fastify = require('fastify')();
fastify.get('/hello', async (request, reply) => {
return { hello: 'world' };
});
fastify.listen(3000, err => {
if (err) throw err;
console.log('Server listening on http://localhost:3000');
});
Other packages similar to @opentelemetry/instrumentation-fastify
@opentelemetry/instrumentation-express
@opentelemetry/instrumentation-express provides similar functionality for Express applications. It allows for automatic tracing and custom span attributes, but is specifically designed for the Express framework rather than Fastify.
@opentelemetry/instrumentation-hapi
@opentelemetry/instrumentation-hapi offers automatic instrumentation for Hapi.js applications. Like @opentelemetry/instrumentation-fastify, it helps in collecting and exporting telemetry data, but it is tailored for the Hapi.js framework.
@opentelemetry/instrumentation-koa
@opentelemetry/instrumentation-koa provides automatic instrumentation for Koa applications. It is similar to @opentelemetry/instrumentation-fastify in terms of functionality but is designed for the Koa framework.
OpenTelemetry Fastify Instrumentation for Node.js
![Apache License](https://img.shields.io/badge/license-Apache_2.0-green.svg?style=flat)
This module provides automatic instrumentation for the fastify
module, which may be loaded using the @opentelemetry/sdk-trace-node
package and is included in the @opentelemetry/auto-instrumentations-node
bundle.
If total installation size is not constrained, it is recommended to use the @opentelemetry/auto-instrumentations-node
bundle with @opentelemetry/sdk-node for the most seamless instrumentation experience.
Compatible with OpenTelemetry JS API and SDK 1.0+
.
Installation
This instrumentation relies on HTTP calls to also be instrumented. Make sure you install and enable both, otherwise you will have spans that are not connected with each other.
npm install --save @opentelemetry/instrumentation-http @opentelemetry/instrumentation-fastify
Supported Versions
Usage
OpenTelemetry fastify Instrumentation allows the user to automatically collect trace data and export them to their backend of choice, to give observability to distributed systems.
To load the instrumentation, specify it in the Node Tracer's configuration:
const { NodeTracerProvider } = require('@opentelemetry/node');
const { registerInstrumentations } = require('@opentelemetry/instrumentation');
const { HttpInstrumentation } = require('@opentelemetry/instrumentation-http');
const { FastifyInstrumentation } = require('@opentelemetry/instrumentation-fastify');
const provider = new NodeTracerProvider();
provider.register();
registerInstrumentations({
instrumentations: [
new HttpInstrumentation(),
new FastifyInstrumentation(),
],
});
See examples/fastify for a short example.
Fastify Instrumentation Options
Options | Type | Example | Description |
---|
requestHook | FastifyCustomAttributeFunction | (span, requestInfo) => {} | Function for adding custom attributes to Fastify requests. Receives parameters: Span, FastifyRequestInfo . |
Using requestHook
Instrumentation configuration accepts a custom "hook" function which will be called for every instrumented Fastify request. Custom attributes can be set on the span or run any custom logic per request.
import { FastifyInstrumentation } from "@opentelemetry/instrumentation-fastify"
const fastifyInstrumentation = new FastifyInstrumentation({
requestHook: function (span: Span, info: FastifyRequestInfo) {
span.setAttribute(
'http.method',
info.request.method,
)
}
});
Semantic Conventions
This package uses @opentelemetry/semantic-conventions
version 1.22+
, which implements Semantic Convention Version 1.7.0
Attributes collected:
Attribute | Short Description |
---|
http.route | The matched route (path template). |
Useful links
License
Apache 2.0 - See LICENSE for more information.