HTTP instrumentation for Pyroscope | Grafana k6 documentation (original) (raw)

This is documentation for the next version of K6. For the latest stable release, go to the latest version.

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Note

The source code for this library can be found in thegrafana/jslib.k6.io GitHub repository.

The http-instrumentation-pyroscope module allows you to instrument HTTP requests in a way that lets you tag Grafana Cloud Profiles with relevant information generated from k6 tests.

The baggage header is a standardized HTTP header used to propagate distributed context. TheW3C specification goes into more detail on the specifics, but like many other headers, the baggage header is a list of key-value pairs.

This module, by default, adds three key-value pairs:

1. Scenario name
2. Name of the request (URL if not set)
3. Value of __ENV.K6_CLOUDRUN_TEST_RUN_ID, which is set automatically in Grafana Cloud k6.

API

Example

This example demonstrates how to use the this library to instrument every HTTP request made in a script with the baggage header.

import { check } from 'k6';
import pyroscope from 'https://jslib.k6.io/http-instrumentation-pyroscope/1.0.2/index.js';
import http from 'k6/http';

// instrumentHTTP will ensure that all requests made by the http module
// from this point forward will have a baggage context attached.
pyroscope.instrumentHTTP();

export default () => {
  // the instrumentHTTP call in the init context replaced
  // the http module with a version that will automatically
  // attach a baggage header to every request.
  const res = http.get('http://httpbin.org/get', {
    headers: {
      'X-Example-Header': 'instrumented/get',
    },
  });
};