Module @opentelemetry/instrumentation-fetch

OpenTelemetry Fetch Instrumentation for web

Note: This is an experimental package under active development. New releases may include breaking changes.

This module provides auto instrumentation for web using fetch. (Note: This instrumentation does not instrument Node.js' fetch. See @opentelemetry/instrumentation-undici for that.)

Installation

npm install --save @opentelemetry/instrumentation-fetch

Usage

import {
  ConsoleSpanExporter,
  SimpleSpanProcessor,
  WebTracerProvider,
} from '@opentelemetry/sdk-trace-web';
import { FetchInstrumentation } from '@opentelemetry/instrumentation-fetch';
import { ZoneContextManager } from '@opentelemetry/context-zone';
import { registerInstrumentations } from '@opentelemetry/instrumentation';

const provider = new WebTracerProvider({
  spanProcessors: [new SimpleSpanProcessor(new ConsoleSpanExporter())]
});

provider.register({
  contextManager: new ZoneContextManager(),
});

registerInstrumentations({
  instrumentations: [new FetchInstrumentation()],
});

// or plugin can be also initialised separately and then set the tracer provider or meter provider
const fetchInstrumentation = new FetchInstrumentation();
const provider = new WebTracerProvider({
  spanProcessors: [new SimpleSpanProcessor(new ConsoleSpanExporter())]
});
provider.register({
  contextManager: new ZoneContextManager(),
});
fetchInstrumentation.setTracerProvider(provider);

// and some test

fetch('http://localhost:8090/fetch.js');

Example Screenshots

Screenshot of the running example

See examples/tracer-web/fetch for a short example.

Fetch Instrumentation options

Fetch instrumentation plugin has few options available to choose from. You can set the following:

Options	Type	Description
`applyCustomAttributesOnSpan`	`FetchCustomAttributeFunction`	Function for adding custom attributes
`requestHook`	`FetchRequestHookFunction`	Function for adding custom attributes or headers before the request is handled
`ignoreNetworkEvents`	`boolean`	Disable network events being added as span events (network events are added by default)
`measureRequestSize`	`boolean`	Measure outgoing request length (outgoing request length is not measured by default)

Semantic Conventions

The instrumentation-fetch versions v0.220.0 and later emit the stable v1.23.0+ semantic conventions.

Span attributes:

v1.23.0 semconv	Notes
`http.request.method`	HTTP request method. With v1.23.0 semconv `http.request.method_original` may also be included.
`url.full`	Full HTTP request URL
`server.address` and `server.port`	The hostname and port of the request URL
`http.response.status_code`	HTTP response status code
`http.request.body.size`	This is only added if `measureRequestSize` is `true`.
`error.type`	The response status (as a string), if the response status was `>=400`.

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.

Classes

FetchInstrumentation

Interfaces

FetchCustomAttributeFunction
FetchInstrumentationConfig
FetchRequestHookFunction