K6 Versions Save

A modern load testing tool, using Go and JavaScript - https://k6.io

v0.50.0

1 month ago

k6 v0.50.0 is here 🎉!

This release:

  • Adds support for uploading files from the browser module.
  • Introduces the options.cloud option.
  • Stabilizes the previously experimental timers module as the k6/timers module.
  • Brings JSON Web Key support to the k6/experimental/webcrypto module.

Breaking changes

  • websockets#60 allows manually setting the name tag, which also overwrites the url tag with the name value. This change makes it consistent with the logic that was implemented in k6 v0.41. Thanks, @mkadirtan for contributing!

Browser APIs to Async

In future releases, we are going to be moving most of the synchronous browser APIs to asynchronous ones (promisifying them). We expect this will affect most of our users, so we are posting this upfront before making the change. Here are the reasons for making this large breaking change:

  1. Most browser APIs use some form of long-running IO operation (networking) to perform the requested action on the web browser against the website under test. We need to avoid blocking JavaScript's runtime event loop for such operations.
  2. We're going to add more asynchronous event-based APIs (such as page.on) that our current synchronous APIs would block.
  3. To align with how developers expect to work with JavaScript APIs.
  4. To have better compatibility with Playwright.

You can find a list of all the APIs that we expect to convert to async in a comment in issue browser#428.

Awaiting on something that’s not a thenable just returns that value, which means you can add the await keyword against APIs that will become async to future proof your test scripts.

New features

Add support for uploading files from the browser module browser#1097, browser#1244

You can now upload files using the available input forms on the website under test. The new API is setInputFiles which can be called from a page, frame or elementHandle types. It can upload one or more files encoded in the test script. To upload files from the local file system, work with the experimental fs module.

Expand to see the examples.

For the following examples, we will use the HTML file:

<html>

<body>
    <form method="POST" action="/upload" enctype="multipart/form-data">
        <input type="file" name="upl" id="upload" multiple />
        <input type="submit" value="Send" />
    </form>
</body>

</html>

Uploading a file can be achieved with the following script:

// Import the k6 encoder module.
import encoding from 'k6/encoding';
...
export default async function () {
  const page = browser.newPage();

  await page.goto(url)

  // Encode and upload some data into a plain text file called test.txt.
  page.setInputFiles('input[id="upload"]', { name: 'test.txt', mimetype: 'text/plain', buffer: encoding.b64encode('Hello World') })
  
  // Click on the submit button on the form to upload the file.
  const submitButton = page.locator('input[type="submit"]')
  await Promise.all([page.waitForNavigation(), submitButton.click()])

  page.close();
}

Uploading multiple files can be done with the use of an array:

page.setInputFiles('input[id="upload"]',
    [{ name: 'test.txt', mimetype: 'text/plain', buffer: encoding.b64encode('Hello World') },
    { name: 'test.json', mimetype: 'text/json', buffer: encoding.b64encode('{"message": "Hello World"}') }])

Thanks to @bandorko! :bow: :tada:

Introducing options.cloud #3348, #3407

In this release, we introduce a new way of defining cloud options. From now on, you can use options.cloud instead of options.ext.loadimpact.

To migrate, you can move the loadimpact object to the root of the options object and rename it to cloud. For example:

export let options = {
    ext: {
        loadimpact: {
            name: "Legacy way of defining cloud options",
            projectID: 12345,
        }
    }
};

export let options = {
    cloud: {
        name: "Current way of defining cloud options",
        projectID: 12345,
    }
};

All scripts with legacy options.ext.loadimpact will continue to function as before. There's no planned sunset date for the legacy option, but we highly encourage using options.cloud going forward. For more details about cloud options, refer to Cloud options.

Timers API becomes part of the k6 core #3587

With this release, the timers API is no longer experimental and can be imported as k6/timers instead of as k6/experimental/timers. The later will be supported until v0.52.0.

You can also contribute to the discussion on making the current timer exports globally available in #3589, or just give it a :+1:.

JSON Web Key support in k6/experimental/webcrypto module webcrypto#61

The experimental webcrypto module now supports the JSON Web Key (JWK) format, using the importKey and exportKey methods.

This allows you to import and export keys in the JWK format for the supported algorithms.

const generatedKey = await crypto.subtle.generateKey({name: "AES-CBC", length: "256"}, true, [ "encrypt", "decrypt"]);

const exportedKey = await crypto.subtle.exportKey("jwk", generatedKey);

UX improvements and enhancements

Browser Context Isolation browser#1112

With this release, we have overhauled and (tremendously) improved the performance and stability of the browser module. It's now possible to run tests with a larger number of VUs concurrently without any performance issues. Previously, when running tests with multiple VUs concurrently, each VU's browser context would attach to the pages from the other VUs' browser contexts. This led to unexpected behavior and performance issues and, to an extent, reduced the module's capability to run multi-VU tests.

Bug fixes

  • #3653 fixes a connectivity issue with non-lowercase options.hosts.
  • browser#1215 fixes a data race during logging that panics.
  • browser#1238 fixes fill functionality for textarea. Thanks @bandorko for the fix! :bow: :tada:
  • browser#1242 fixes XPath evaluation on DocumentFragment.

Maintenance and internal improvements

  • webcrypto#62 fixes display error message in the console and does minor maintenance.
  • webcrypto#60 leverages some of the k6 APIs to handle JavaScript operations.
  • webcrypto#59 makes newTestSetup rely on k6's modulestest.
  • webcrypto#58 addresses linter issues related to repeated static strings.
  • 3633 updates k6 dependencies.

v0.49.0

3 months ago

k6 v0.49.0 is here 🎉! This release:

  • Adds a built-in web dashboard that displays test results in real time.
  • Introduces clear functionality to the browser module's locator classes.
  • Merges the gRPC experimental module back into the gRPC core module.
  • Enables the ability to get the selection from an element in k6/html.
  • Collects internal modules and outputs used by a script.
  • Prepares k6/experimental/timers for stabilization.

Breaking changes

  • #3494 stops updating loadimpact/k6 docker image. If you still use it, please migrate to the grafana/k6 image.
  • browser#1111 removes timeout option for isVisible and isHidden since the API no longer waits for the element to appear on the page.

New features

Web Dashboard

The new web dashboard brings real-time visualization to load testing. This feature allows users to monitor test progress and analyze results dynamically, enhancing the overall testing experience.

Real-time test results

Activate this feature using the environment variable K6_WEB_DASHBOARD=true. For this initial release, the dashboard is not enabled by default to allow users to opt into this new experience as it evolves.

K6_WEB_DASHBOARD=true k6 run script.js

Once enabled and the test script is running, navigate to http://localhost:5665 in your web browser to access the dashboard.

k6 Web Dashboard Overview

Test report

The web dashboard also offers an HTML test report (see an example) for detailed analysis, enabling easy sharing and downloading capabilities for collaboration.

To access and download the report, click on the Report button in the dashboard's top right corner or use the K6_WEB_DASHBOARD_EXPORT environment variable.

K6_WEB_DASHBOARD=true K6_WEB_DASHBOARD_EXPORT=test-report.html k6 run script.js

Add clear to the locator class browser#1149

The new clear method on the locator class clears the text boxes and input fields. This is useful when navigating to a website where the text boxes and input fields already contain a value that needs to be cleared before filling it with a specific value.

Expand to see an example of the new functionality. 
import { check } from 'k6';
import { browser } from 'k6/experimental/browser';

export const options = {
  scenarios: {
    ui: {
      executor: 'shared-iterations',
      options: {
        browser: {
            type: 'chromium',
        },
      },
    },
  },
}

export default async function() {
  const context = browser.newContext();
  const page = context.newPage();

  await page.goto('https://test.k6.io/my_messages.php', { waitUntil: 'networkidle' });
  
  // To mimic an input field with existing text.
  page.locator('input[name="login"]').type('admin');

  check(page, {
    'not_empty': p => p.locator('input[name="login"]').inputValue() != '',
  });

  // Clear the text.
  page.locator('input[name="login"]').clear();

  check(page, {
    'empty': p => p.locator('input[name="login"]').inputValue() == '',
  });

  page.close();
}

Add tracing to the browser module browser#1100

The browser module now generates traces that provide a representation of its inner workings, such as API methods executed (for example browser.newPage and page.goto), page navigations, and Web Vitals measurements.

Currently, the instrumented methods are a subset of all the methods exposed by the browser module API, but this will be extended in the future.

The traces generation for the browser module depends on the overall k6 traces option introduced in v0.48.0. Check out the documentation to learn more about it.

gRPC streaming API becomes part of the k6 core #3490

With this release, gRPC's streaming API becomes part of the core's k6/net/grpc module. The experimental k6/experimental/grpc has been back-merged into the core.

You can still use import k6/experimental/grpc for a couple of releases, but it's deprecated and will be removed in the future (planned in k6 version v0.51.0).

To migrate your scripts, replace k6/experimental/grpc with k6/net/grpc in your script imports, and the code should work as before.

k6/html: Extract selection from element #3519

k6/html has been around for a while and allows you to search within an HTML document with a jQuery-like API called Selection, and also has support for the more standard Element that represents DOM element.

For a long time, you could get an Element from a Selection using the .get(index), but you couldn't get back to a Selection from an Element.

This is not a common case, but one that requires quite a bit of code. For example, see the following jQuery snippet:

let li = http.get("https://test.k6.io").html().find("li");
li.each(function(_, element) {
    // here element is an element not a selection
    // but what if for each li we want to select something more?
    // in jquery that will be:
   let container = $(element).closest('ul.header-icons');
    // but what should `$` do?
    // in a browser there is only 1 html document that you have access to
    // in k6 though you can be working with multiple ones, so `$` can't know which one it should
    // work against
});

In order to support the above example, you can use selection, without going to the element:

let li = http.get("https://test.k6.io").html().find("li");
for (; li.size() > 0; li = li.next()) {
    let ul = li.closest('ul.header-icons'); // li here is still a selection and we iterate over it.
}

This is not always possible though, and arguably isn't what most users will naturally do.

Because of this, we have now added a new .selection() which returns a selection for its element.

   let li = http.get("https://test.k6.io").html().find("li");
   li.each(function(_, element) {
      let container = element.selection().closest('ul.header-icons');
        // .. more code
   });

Thanks to @Azhovan! :bow: :tada:

Collect usage data on imported internal modules and outputs #3525

k6 now collects usage data of the modules and outputs that are being used when the usage report is enabled. The data collection is only related to the built-in k6 modules and outputs. Private, custom modules and extensions are never collected. The usage report is enabled by default in k6, but it is possible to opt-out using the no-usage-report option.

We always want to improve the product, but at the same time, we need to pay attention to where we allocate our resources. Having data of what are the most used modules and outputs gives us better confidence to make decisions because we are supported by data. The data can let us know what percentage of our users will benefit from the introduction of a new feature and also, how many of them would be impacted in case of a breaking change.

UX improvements and enhancements

  • #3529 enables the k6 cloud traces output by default.
  • #3440 adds a fallback for using built-in certificates if the OS provides none. Thanks to @mem for working on it!
  • browser#1104 adds support for browser module traces metadata. Users can define key-value metadata that will be included as attributes in every generated span.
  • browser#1135 improves the array output from console in the k6 logs.
  • browser#1137, browser#1145 improves the error messages displayed when Chrome or Chromium isn't found.
  • #3543 replaces documentation URLs to grafana.com/docs/k6/latest/.

Bug fixes

  • #3485 fixes the REST API always logging a 200 status code response, which was found as part of fixing lint issues in the code.
  • browser#1129 mitigates the risk of panics when the website under test uses the console.
  • browser#1133 fixes BigInt parsing.
  • browser#1108, browser#1110 fixes isVisible and isHidden so that it doesn't wait for an element to match with the given selector, allowing it to continue on with the test script when elements are not on the page.
  • browser#1121 fixes dblClick so that it works with onDblClick and performs two clicks on the specified element.
  • browser#1152 fixes a nil pointer dereference when navigating around on SPA websites.

Maintenance and internal improvements

  • #3204 internal refactor to make future distributed execution work easier. With a small fix to tests in #3531. Thanks to @na-- :tada:.
  • Lint fixes throughout the k6 code base #3460, #3462, #3463, #3478, #3479, #3480, #3481, #3482, #3483, #3484, #3485, #3495.
  • #3473 refinements to the release process.
  • Dependency updates across k6 #3500, #3501, #3502, #3503, #3509, #3513, #3537, #3539, #3540.
  • #3489 migrates pull-requests assignment to CODEOWNERS from GitHub Action.
  • #3496 checks for security issues with a scheduled trivy scan.
  • #3517 adds unit tests to the cloadapi package. This is the first contribution by external contributor @nilskch. Thanks for this @nilskch :bow:.
  • #3520 stops using deprecated by golang net.Dialer.DualStack option.
  • #3526 refactors to JavaScript package test around open and require and their handling of paths.
  • #3527 generates test certificates for more tests during the test. This, among other things, fixes macOS tests.
  • #3528 enables macOS tests in GitHub Actions.
  • browser#1134 adds a new error type when parsing objects.
  • browser#1107, browser#1109 refactor internals.

Roadmap

As mentioned earlier, there's work in progress to make xk6-timers stable as part of the next release. You can find more information on issue #3297.

v0.48.0

4 months ago

k6 v0.48.0 is here 🎉! This release includes:

  • Numerous long-awaited breaking changes.
  • A new k6 new subcommand to generate a new test script.
  • A new k6/experimental/fs module for file interactions.
  • CPU and network throttling support for the k6 browser module.

Breaking changes

This release includes several breaking changes, mainly cleaning up deprecations from previous versions. They should have a straightforward migration process, and not heavily impact existing users.

  • #3448 limits metric names, aligning to both OpenTelemetry (OTEL) and Prometheus name requirements, while still being limited to 128 ASCII characters. Warnings about the limit started in v0.45.
  • #3439 changes the Client signature in k6/experimental/redis module. Refer to the module-related section below.
  • #3350 removes the grpc.invoke()'s parameter headers, deprecated in k6 v0.37. Use the metadata parameter instead.
  • #3389 removes the --logformat flag, deprecated in v0.38. Use the --log-format flag instead.
  • #3390 removes all CSV output's CLI arguments, deprecated in v0.35. This change makes the CSV output consistent with other output formats.
  • #3365 removes the k6 convert CLI command, deprecated in v0.41. Use the har-to-k6 package instead.
  • #3451 removes logic that would attempt to prepend a https:// scheme to module specifiers that were not recognized. Deprecated in k6 v0.25. Use full URLs if you want to load remote modules instead.

New features

Add k6 new subcommand #3394

k6 now has a new subcommand that generates a new test script. This is useful for new users who want to get started quickly, or for experienced users who want to save time when creating new test scripts. To use the subcommand, open your terminal and type:

k6 new [filename]

If no filename is provided, k6 uses script.js as the default filename. The subcommand will create a new file with the provided name in the current directory, and populate it with a basic test script that can be run with k6 run.

Add a k6/experimental/fs module #3165

k6 now has a new k6/experimenal/fs module providing a memory-efficient way to handle file interactions within your test scripts. It currently offers support for opening files, reading their content, seeking through it, and retrieving metadata about them.

Unlike the traditional open function, which loads a file multiple times into memory, the filesystem module reduces memory usage by loading the file as little as possible, and sharing the same memory space between all VUs. This approach significantly reduces the memory footprint of your test script and lets you load and process large files without running out of memory.

For more information, refer to the module documentation.

Expand to see an example of the new functionality.

This example shows the new module usage:

import fs from 'k6/experimental/fs';

// k6 doesn't support async in the init context. We use a top-level async function for `await`.
//
// Each Virtual User gets its own `file` copy.
// So, operations like `seek` or `read` won't impact other VUs.
let file;
(async function () {
  file = await open('bonjour.txt');
})();

export default async function () {
  // About information about the file
  const fileinfo = await file.stat();
  if (fileinfo.name != 'bonjour.txt') {
    throw new Error('Unexpected file name');
  }

  const buffer = new Uint8Array(128);

  let totalBytesRead = 0;
  while (true) {
    // Read into the buffer
    const bytesRead = await file.read(buffer);
    if (bytesRead == null) {
      // EOF
      break;
    }

    // Do something useful with the content of the buffer
    totalBytesRead += bytesRead;

    // If bytesRead is less than the buffer size, we've read the whole file
    if (bytesRead < buffer.byteLength) {
      break;
    }
  }

  // Check that we read the expected number of bytes
  if (totalBytesRead != fileinfo.size) {
    throw new Error('Unexpected number of bytes read');
  }

  // Seek back to the beginning of the file
  await file.seek(0, SeekMode.Start);
}

Redis (m)TLS support and new Client constructor options #3439, xk6-redis/#17

In this release, the k6/experimental/redis module receives several important updates, including breaking changes.

Connection URLs

The Client constructor now supports connection URLs to configure connections to Redis servers or clusters. These URLs can be in the format redis://[[username][:password]@][host][:port][/db-number] for standard connections, or rediss://[[username][]:password@]][host][:port][/db-number] for TLS-secured connections. For more details, refer to the documentation.

Example usage
import redis from 'k6/experimental/redis';

const redisClient = new redis.Client('redis://someusername:somepassword@localhost:6379/0');

Revamped Options object

The Client constructor has been updated with a new Options object format. This change aligns the module with familiar patterns from Node.js and Deno libraries, offering enhanced flexibility and control over Redis connections. For more details, refer to the documentation.

Expand to see an example of the new functionality.

This example shows the usage of the new Options object:

import redis from 'k6/experimental/redis';

const redisClient = new redis.Client({
  socket: {
    host: 'localhost',
    port: 6379,
  },
  username: 'someusername',
  password: 'somepassword',
});

(m)TLS support

The Redis module now includes (m)TLS support, enhancing security for connections. This update also improves support for Redis clusters and sentinel modes (failover). For connections using self-signed certificates, enable k6's insecureSkipTLSVerify option (set to true).

Expand to see an example of the new functionality.

This example shows the configuration of a TLS connection:

import redis from 'k6/experimental/redis';

const redisClient = new redis.Client({
  socket: {
    host: 'localhost',
    port: 6379,
    tls: {
      ca: [open('ca.crt')],
      cert: open('client.crt'), // client certificate
      key: open('client.key'), // client private key
    },
  },
});

Add tracing instrumentation #3445

k6 now supports a new traces output option that allows you to configure the output for traces generated during its execution. This option can be set through the --traces-output argument in the k6 run command or by setting the K6_TRACES_OUTPUT environment variable.

Currently, no traces are generated by k6 itself, but this feature represents the first step towards richer tracing functionalities in k6 and its extensions.

By default traces output is set to none, and currently the only supported output is otel which uses the opentelemetry-go's Open Telemetry API and SDK implementations. The format for the otel traces output configuration is the following:

--traces-output=<endpoint>[,opt1=val1,opt2=val2]

Where opts can be one of the following options:

  • proto: Specifies the protocol to use in the connection to the traces backend. Supports grpc (default) and http.
  • header.<header_name>: Specifies an additional header to include in the connection to the traces backend.

Example:

K6_TRACES_OUTPUT=https://traces.k6.io/v1/traces,proto=http,header.Authorization=Bearer token

Add support for browser module's page.throttleCPU browser#1095

The browser module now supports throttling the CPU from chrome/chromium's perspective by using the throttleCPU API, which helps emulate slower devices when testing the website's frontend. It requires an argument of type CPUProfile, which includes a rate field that is a slow-down factor, where 1 means no throttling, 2 means 2x slowdown, and so on. For more details, refer to the documentation.

...
  const context = browser.newContext();
  const page = context.newPage();

  try {
    page.throttleCPU({ rate: 4 });
...

Add support for browser module's page.throttleNetwork browser#1094

The browser module now supports throttling the characteristics of the network from chrome/chromium's perspective by using the throttleNetwork API, which helps emulate slow network connections when testing the website's frontend. It requires an argument of type NetworkProfile, with a definition of:

export interface NetworkProfile {
    /*
     * Minimum latency from request sent to response headers received (ms).
     */
    latency: number;
    
    /*
     * Maximal aggregated download throughput (bytes/sec). -1 disables download
     * throttling.
     */
    download: number;
    
    /*
     * Maximal aggregated upload throughput (bytes/sec). -1 disables upload
     * throttling.
     */
    upload: number;
}

You can either define your own network profiles or use the ones we have defined by importing networkProfiles from the browser module. For more details, refer to the documentation.

import { browser, networkProfiles } from 'k6/experimental/browser';
...
  const context = browser.newContext();
  const page = context.newPage();

  try {
    page.throttleNetwork(networkProfiles['Slow 3G']);
...

k6's documentation is moving under grafana.com/docs/k6

It's not directly part of the k6 v0.48 release, but we believe it is worth mentioning that we're moving the documentation from k6.io/docs to grafana.com/docs/k6.

The legacy documentation space k6.io/docs will be available for a while, but we encourage you to update your bookmarks and links to the new domain.

UX improvements and enhancements

  • browser#1074 adds a new browser.closeContext() method to facilitate closing the current active browser context.
  • #3370 adds a new flag --profiling-enabled which enables exposing pprof profiling endpoints. The profiling endpoints are exposed on the same port as the HTTP REST API under the /debug/pprof/ path. This can be useful for extension developers.
  • #3442 adds a new --version flag, which has the same output as k6 version command. Thanks, @ffapitalle!
  • #3423 adds an environment variable K6_INFLUXDB_PROXY to the InfluxDB output which allows specifying proxy. Thanks, @IvanovOleg!
  • #3398 enables k6 cloud traces by default.
  • #3400 sets a binary-based cloud output (a.k.a. cloud output v2) as the default version for streaming metrics from a local test run via -o cloud.
  • #3452 adds fsext.Abs helper function.

Bug fixes

  • #3380 corrects console.debug(), aligning -v output to --console-output and stdout.
  • #3416 prints the stack trace when there's an exception in handleSummary().
  • #3438 prevents an error on HTTP requests with content-encoding header and HTTP statuses known for having no body.
  • browser#1077 fixes browserContext.clearPermissions to clear permissions without panic.
  • browser#1042 fixes browserContext.waitForEvent which involved promisifying the waitForEvent API.
  • browser#1078 fixes request interception deadlock to improve stability.
  • browser#1101 fixes page.$ so that it returns null when no matches with given selector are found.
  • #3397, #3427, #3417 update goja dependency. Fixes a possible panic and proper handling circular types at JSON.stringify. Fixes an issue about dumping the correct stack trace when an error is re-thrown.
  • browser#1106 fixes an NPE on NavigateFrame when navigate occurs in the same document.
  • browser#1096 fixes a panic when trying to interact within nested iframes. Thanks, @bandorko!

Maintenance and internal improvements

  • #3378 fixes usage of gh in GitHub actions creating the OSS release.
  • #3386, #3387, #3388, browser#1047 update dependencies.
  • #3393, #3399 fix lint issues in the js package.
  • #3381 disables temporarily ARM tests on GitHub Actions.
  • #3401, #3469 refactors a Makefile, removes make ci-like-lint in favor of make lint. Updates a golangci-lint version to v1.55.2.
  • #3410 fixes the tests reference in the all rule of the Makefile. Thanks, @flyck!
  • #3402 adds a test-case for the k6 cloud.
  • #3421 updates dependencies for xk6 integration tests.
  • browser#1075, browser#1076 refactors clearPermissions and grantPermissions.
  • browser#1043 refines tests.
  • browser#1069, browser#1090 refactor internal.
  • browser#1102 uses force and noWaitAfter in frame.newAction.
  • #3443 mentions that k6-core team aims to support the last two major golang versions for building a k6 binary.
  • #3437 switches k6 cloud traces to a new hostname.
  • #3429 increases timeout expectations for the TestSetupTimeout test.
  • #3446 moves log tokenizer to lib/strvals package.

Roadmap

Graduating from experimental

It has been a while since we've introduced the k6/experimental namespace. This namespace was specifically created to test new features before we fully committed to them. Thanks to it, we have been able to iterate on features and receive valuable feedback from the community before adding them to the core of k6.

In the following releases, we're going to graduate k6/experimental/grpc and k6/experimental/timers.

These modules' "experimental" versions will remain available for a couple of releases, but the goal is to remove the "experimental" imports for them in favor of the core-only imports.

New dashboard features

We're happy to announce our work on a new, upcoming dashboard feature. Based on the xk6-dashboard extension, this upcoming feature will enable you to visualize your test runs and their results in your web browser, in real time. The k6 maintainers team is starting to work towards its integration into the core of k6, and we're aiming to release it in the next couple of releases.

While the final user-experience might differ, you can already try it out by following the instructions in the xk6-dashboard repository. We update the extension on a regular basis as we're converging towards the first release of the feature in k6. Go ahead and give it a try! Let us know what you think about it!

v0.47.0

6 months ago

k6 v0.47.0 is here 🎉! This release includes:

Deprecations

  • #3347 The built-in statsd output option has been deprecated, and users should use the xk6-output-statsd extension instead. See #2982 for future plans.
  • #3288 Loading remote modules now requires users to prepend them with https://. Before, k6 would try to resolve importing remote modules by prepending https:// if it was missing. This behavior has been deprecated and will be fully removed in the next release (v0.48.0).

New features

Add gRPC's binary metadata support #3234, xk6-grpc#46

The k6 gRPC modules (k6/net/grpc and k6/experimental/grpc) now support handling binary metadata that uses the -bin postfix, according to the gRPC specification.

let resp = client.invoke("grpc.testing.TestService/EmptyCall", {}, { metadata: { "X-Load-Tester-bin": new Uint8Array([2, 200]) } })

Thanks to @sapphire-janrain for the contribution!

Add gRPC's reflection metadata support #3343, xk6-grpc#46

The k6 gRPC modules (k6/net/grpc and k6/experimental/grpc) now support adding metadata to reflection requests by using a new connection parameter reflectMetadata.

Higher precision for Trend metrics in Grafana Cloud k6 #3302

Grafana Cloud k6 is now able to store and visualize Trend metrics up to 3 digits of precision for decimal numbers.

Docker support for browser-based tests #3199

k6 is now publishig Docker images that include Chromium web browser. This allows k6 users to run tests that use Browser API without having to install Chrome first. Check the "A note on running browser tests" section of the Overview page on DockerHub for details.

Docker images for ARM64 architecture #3320

The k6's release process now builds and pushes dedicated Docker images for ARM64. Check k6's tags page on DockerHub for details.

New authentication methods and HTTP headers API for Prometheus remote write output xk6-output-prometheus-remote#143, xk6-output-prometheus-remote#145, xk6-output-prometheus-remote#147

The experimental Prometheus remote write output now supports two new authentication methods: Bearer token and TLS certificates. Check out the documentation to learn more about how to define them using the new environment variables. We've also added the K6_PROMETHEUS_RW_HTTP_HEADERS that defines a new and more convenient way to set custom HTTP headers to pass through each flush metrics' request.

The browser module now provides a more complete and robust API for handling cookies. The cookie API was stabilized by defining a new Cookie class (browser#1008, browser#1030) that can be used while creating and retrieving cookies. This enabled us to add a new browserContext.cookies([urls]) method (browser#1005) that returns all cookies from the current browser context. The new API also supports filtering cookies by URL (browser#1016).

That led to fixing a bug where the expires field was not being set correctly while adding cookies using the context.addCookie() method (browser#1031). Lastly, the existing context.clearCookies() method was fixed to clear all cookies from the current browser context (browser#1040).

const context = browser.newContext();
context.addCookies([
    {name: 'foo', value: 'bar', url: 'https://test.k6.io'},
    {name: 'baz', value: 'qux', url: 'https://grafana.com'},
]);

const cookies = context.cookies('https://test.k6.io');
console.log(cookies.length);         // 1
console.log(cookies[0].name);        // foo
console.log(cookies[0].value);       // bar

context.clearCookies();
console.log(context.cookies.length); // 0

Add support for browser module's page.on('console') browser#1006

Allows users to register a handler to be executed every time the console API methods are called from within the page's JavaScript context. The arguments passed into the handler are defined by the ConsoleMessage class.

page.on('console', msg => {
    check(msg, {
        'assertConsoleMessageType': msg => msg.type() == 'log',
        'assertConsoleMessageText': msg => msg.text() == 'this is a console.log message 42',
        'assertConsoleMessageArgs0': msg => msg.args()[0].jsonValue() == 'this is a console.log message',
        'assertConsoleMessageArgs1': msg => msg.args()[1].jsonValue() == 42,
    });
});

page.evaluate(() => console.log('this is a console.log message', 42));

UX improvements and enhancements

  • #3338, xk6-grpc#48 Adds support for the gRPC reflection protocol v1.
  • #3290 Adds error logging when executing setup and teardown via REST API. Thanks to @kmtym1998 for the contribution!
  • #3327 Adds commit identifier for the k6 build when running k6 version.
  • #3340 Updates k6 *-with-browser Docker images to automatically set the no-sandbox environment variable.
  • #3335 The character limit for metric names increased from 63 to 128 after the OpenTelemetry update. k6 will return an error starting on the next release (v0.48.0) if users hit the limit.
  • browser#1007 Adds a k6 object (window.k6 = {};) to help identify k6 browser module tests.
  • browser#1022 Refactors the check in examples/fillform.js so that it matches the type definitions and documentation for check.

Bug fixes

  • xk6-grpc#47 Fixes the premature closing of a gRPC stream when a stream's client has finished sending. Thanks to @thiagodpf for reporting!
  • #3344, xk6-grpc#49 Adds support for Google's protobuf wrappers. Thanks to @zibul444 for reporting!
  • #3308 Updates goja version, and fixes a compiler bug when a class is declared in a function with an argument.
  • browser#1039 Fixes goja conversions while adding and retrieving cookies.
  • browser#1038 Fixes read/write data race for edge case with remote browsers.
  • browser#1034 Fixes page.reload & page.setContent to use the default navigation timeout over the default timeout.
  • browser#1033 Fixes the page timeouts so it is actually used after being set.

Maintenance and internal improvements

  • #3342 Updates xk6-grpc to the latest version. This change brings all the latest fixes and improvements to the experimental gRPC module.
  • #3271,#3272 Updates the golangci version and adds the interfacebloat linter.
  • #3279 Fixes the CI not publishing the SBOM file on a new release.
  • #3283 Updates the Go version in k6's CI used to build the binaries.
  • #3341, #3339 Updates goja, includes runtime initialization speed-up and a fix for source indexes.
  • #3311 Updates the alpine image version that is used as the base of the k6 Docker image.
  • browser#1043, browser#1021, browser#1019, browser#1014 Fixes xk6-browser tests.
  • browser#1000, browser#1024 Refines xk6-browser issue and PR templates.
  • browser#1003, browser#1009, browser#1010 Internal changes to xk6-browser.
  • browser#997 Updates xk6-browser readme.
  • browser#962 CI fixes.
  • browser#1035 Refactors int64 timeout to time.Duration, to help avoid confusion as to whether a timeout is in milliseconds or seconds.

Roadmap

Native ECMAScript Modules support

Work on this epic issue has been picked up and there is some progress in the underlying implementation.

One of the main internal changes will be dropping Babel, which is currently used to transpile ESM code to CommonJS.

For users, it will mean better JavaScript support as this change will automatically get object spread working and likely faster startup for big scripts. In the future, this also means JavaScript compatibility will be easier to add, since it'll only need to be supported in the JavaScript VM we use - goja.

There's a risk that some k6 tests using both CommonJS and ECMAScript modules syntax will change in behavior. In practice, using both should never really be done as they're not compatible.

Because there are risks involved, we are going to do this very carefully and only once we have done a lot of tests. That means this is currently planned for v0.49.0, but with the majority of the remaining work done in the v0.48.0 cycle.

This way, we will also be able to have most of our users test these changes from our master branch, using Docker images, for example.

Future breaking changes

There are several changes in the next release that are entering the final stage of their deprecation period. That means the next release will include the following breaking changes:

  • #3065 Metric names will be limited to 128 characters and a set of allowed symbols. This was going to be changed to a 63 character limit to ensure compatibility with OpenTelemetry standards, but since then, the OTel limit has been updated to 255 characters. You can find more details about the changes in the linked issue.
  • #3365 The k6 converter command will be removed.
  • #3350 The headers param for the gRPC module will be removed. Users should use the metadata property instead.
  • #3287 Loading remote modules will require users to include the https:// protocol in their URLs, otherwise it will return an error.
  • CSV output no longer accepts arguments in snake case (for example, fileName should be used instead of file_name).
  • The --logformat flag for defining the Log format option will be removed. --log-format should be used instead.

We recommend checking this list to see if you are impacted, and updating your scripts or CI/CD processes to avoid any issues. If you have any feedback, please open an issue.

v0.46.0

8 months ago

k6 v0.46 is here 🎉! This release includes:

  • xk6-browser extension version bump to v1.0.2, which includes breaking changes.
  • Send custom headers to Loki log output
  • Cloud Traces, the new integration between k6 and Tempo
  • Ability to configure TLS per gRPC connection
  • Cloud output v2
  • And many UX improvements, bug fixes, and internal improvements

Breaking Changes

Browser

In this release, the xk6-browser extension version is bumped up to v1.0.2, as it includes multiple breaking changes concerning options, browser lifecycle, and metrics. See the migration guide for making your test scripts compatible with the new version.

Options devtools, env and proxy are deprecated (browser#868, browser#870, browser#872). Additionally, browser launch/connect options are no longer defined in the corresponding JS API methods, instead the test execution related options are now defined inside the browser scenario options (see #3036), and the other more "environmental options", such as headless, debug, executablePath, are set as ENV vars. Also, the slowMo option is no longer supported, although it might be supported again in the future through a different API (browser#876).

Metrics also went through a few changes. The Web Vitals metrics are renamed to use the browser_ prefix and short namings (e.g.: webvital_first_input_delay -> browser_web_vital_fid) (browser#885, browser#903), and the rating metric is removed, as it is now set as a label in the corresponding Web Vitals metrics (browser#915). The browser HTTP metrics have also been modified, as these are now split from the HTTP module ones, so there are new browser_ prefixed HTTP metrics, specifically for request duration and failed requests (browser#916).

Another big change introduced in this version affects the way the browser lifecycle is handled. Users no longer have to explicitly initialize/close the browser instance through the JS API. Instead, a browser instance will be automatically initialized/closed at the beginning/end of each iteration if the browser type is set in scenario options (see #3036). This also means that the chromium entity from k6/experimental/browser import path is no longer valid. Instead, the browser entity provides access to the browser methods such as browser.newPage() (browser#910, browser#944). This change means that the browser.on() method is no longer applicable, and therefore it has been removed (browser#919).

Additionally, related to import changes, the browser module version is no longer an exported field (browser#923).

Last but not least, this release also includes constraints on browser contexts usage as now only one browserContext is allowed per iteration, which means that the user can create a new browserContext, close it, and then create it again; but can not have more than one "live" browserContext. Instead, scenarios should be used to separate independent actions in a test (browser#929, browser#945).

With all these changes, a simple browser test now looks like:

import { browser } from 'k6/experimental/browser';

export const options = {
  scenarios: {
    ui: {
      executor: 'shared-iterations',
      options: {
        browser: {
          type: 'chromium', // chromium is the only supported browser type so as long as
                            // the option is set, Chromium/Google Chrome will be used
        },
      },
    },
  },
};

export default async function () {
  const page = browser.newPage();
  try {
    await page.goto('https://grafana.com')
  } finally {
    page.close();
  }
}

Deprecations

  • #3121 deprecates the loadimpact/k6 docker image. We recommend switching to the grafana/k6 image as soon as possible.

New features

Loki log output sending additional headers #3227

k6 has been able to send logs to Loki for nearly 3 years since v0.28.0 but didn't support any way to authenticate.

Now, it can be configured to send additional headers on every request.

This can be done by using the new header config option, similar to label:

k6 --log-output=loki=http://example.org,header.X-My-Header=123,header.Authorization=mytoken ...

The example above will now send the header X-My-Header with the value 123 and the Authorization header with the value mytoken.

Thanks to @federicotdn for adding this feature.

Cloud Traces #3100, #3202

This release supports the new integration between k6 and Tempo in the cloud. Grafana Cloud k6 and Grafana Cloud Tempo customers will be able to start their traces in k6 using the existing k6/experimental/tracing module to enrich their test run analysis page with metrics and aggregations from tracing data.

The new Cloud traces will work "out of the box" for k6 cloud runs. In case of k6 run execution, the K6_CLOUD_TRACES_ENABLED environment variable has to be set to true.

Ability to configure TLS per gRPC connection #3159, xk6-grpc#25

The k6/net/grpc and k6/experimental/grpc modules now support configuring TLS per-connection via ConnectParams. This is useful when connecting to a single gRPC server, using different TLS settings for each VUs, as well as when connecting to multiple gRPC servers from the same VU.

Expand to see an example of the new functionality. 
import grpc from "k6/experimental/grpc";
import { check } from "k6";
import { SharedArray } from "k6/data";
import exec from "k6/execution";

// note: the services in this example don't exist. If you would like
// to run this example, make sure to replace the URLs, and
// the cacerts, cert, key, and password variables.
const grpcArgs = new SharedArray("grpc", () => {
    // Using SharedArray here so that not every VU gets a copy of every certificate a key
    return [
        {
            host: "foo1.grpcbin.test.k6.io:9001",
            plaintext: false,
            params: {
                tls: {
                    cacerts: [open("cacerts0.pem")],
                    cert: open("cert0.pem"),
                    key: open("key0.pem"),
                },
            },
        },
        {
            host: "foo2.grpcbin.test.k6.io:9002",
            params: {
                plaintext: false,
                tls: {
                    cacerts: open("cacerts1.pem"),
                    cert: open("cert1.pem"),
                    key: open("key1.pem"),
                    password: "cert1-passphrase",
                },
            },
        },
    ];
});

const client = new grpc.Client();

export default () => {
    if (__ITER === 0) {
        // Take one config and use it for this one VU
        let grpcArg = grpcArgs[exec.vu.idInTest % grpcArgs.length];
        client.connect(grpcArg.host, grpcArg.params);
    }

    const response = client.invoke("hello.HelloService/SayHello", {
        greeting: "Bert",
    });

    check(response, {
        "status is OK": (r) => r && r.status === grpc.StatusOK,
    });

    console.log(JSON.stringify(response.message));
};

Thanks @chrismoran-mica for the contribution 🙇‍♂️.

Cloud Output v2 #3117

After years of great service, we decided to refresh the k6 Cloud output introducing a more efficient end-to-end solution for ingesting the generated tests' metrics. The main change regards the protocol used for flushing metrics that is now a binary-based payload over HTTP.

The new output reduces the resources a load generator uses for tests that produce many metrics. There is no significant difference in the user experience; it's expected to be the same.

The one thing worth highlighting is that the new output is strict about tags, and it'll drops tags if they are reserved. For example:

  • A custom tag named test_run_id, since that is reserved for internal k6 Cloud operations
  • Any tag with a key that starts with two underscores (__), that is marked by Prometheus convention as reserved

This is not yet the default Cloud output for the test runs executed from local machines (k6 run -o cloud), but it is expected to be transparently enabled in the upcoming weeks.

The full list of related PRs: #3104, #3108, #3120, #3125, #3162, #3169, #3182, #3186, #3187, #3193, #3195, #3206, #3226, #3157, #3172.

UX improvements and enhancements

  • #3176 Adds a js/promises package, which enables extension developers to easily create promises that will be dispatched to the eventloop using the New function.
  • #3181 Adds a RunOnEventLoop method to the modulestest.Runtime type, which allows extensions developers to run code on the event loop from their tests.
  • xk6-grpc#19 Fixes EOF (end of file) error that was produced when writing to a closed gRPC stream. Additionally, if no error handlers are set up, the error is logged to the console.
  • browser#881 Adds a new browser_http_req_failed metric.
  • browser#901 Adds support for shadow DOM piercing in locator. Thanks to @tmc for its implementation.
  • browser#953 Improves Web Vitals reporting for better accuracy and consistency.

Bug fixes

  • #3178, xk6-grpc#23 Fixes the registration of nested protobuf messages in the gRPC module. Thanks @thiagodpf for reporting and fixing the bug!
  • #3194 Fixes loki log output exiting before push is finished.
  • #3231 Fixes the tracing module sampling option to default to 1.0 when not set by the user.
  • browser#866 Disables the timeout on browser process execution.
  • browser#942 Fixes deadlock in frameNavigated.
  • browser#943 Fixes a race condition in navigation and lifecycle events.
  • browser#979 Fixes a deadlock on pagehide event evaluation when page.close() is called.
  • browser#980 Fixes Loki log output for console log serializer.
  • browser#991 Fixes data directory not being cleared during browser.close() panic.

Maintenance and internal improvements

v0.45.1

8 months ago

k6 v0.45.1 is a patch release that fixes the build process for extensions:

  • #3252, #3253 Due to the deletion of the go.buf.build registry that is used by the Prometheus remote write output, the building process for extensions has been broken.

There are no functional changes in k6 compared to v0.45.0.

v0.45.0

10 months ago

k6 v0.45.0 is here 🎉! This release includes:

  • Experimental gRPC streaming support.
  • Update scripts in the cloud without running tests.
  • JS Metadata API.
  • A lot of internal changes and bugfixes.

Breaking changes

New features

Experimental gRPC module with streaming support #3107

There is a new experimental module k6/experimental/grpc. It is a copy of the k6/net/grpc module with added stream support #2020.

Expand to see an example of the new functionality.

This example shows server streaming:

import { Client, Stream } from 'k6/experimental/grpc';
import { sleep } from 'k6';

const COORD_FACTOR = 1e7;
// to run this sample, you need to start the grpc server first.
// to start the grpc server, run the following command in k6 repository's root:
// go run -mod=mod examples/grpc_server/*.go
// (golang should be installed)
const GRPC_ADDR = __ENV.GRPC_ADDR || '127.0.0.1:10000';
const GRPC_PROTO_PATH = __ENV.GRPC_PROTO_PATH || '../../grpc_server/route_guide.proto';

let client = new Client();

client.load([], GRPC_PROTO_PATH);

export default () => {
  client.connect(GRPC_ADDR, { plaintext: true });

  const stream = new Stream(client, 'main.FeatureExplorer/ListFeatures', null);

  stream.on('data', function (feature) {
    console.log(
      'Found feature called "' +
        feature.name +
        '" at ' +
        feature.location.latitude / COORD_FACTOR +
        ', ' +
        feature.location.longitude / COORD_FACTOR
    );
  });

  stream.on('end', function () {
    // The server has finished sending
    client.close();
    console.log('All done');
  });

  stream.on('error', function (e) {
    // An error has occurred and the stream has been closed.
    console.log('Error: ' + JSON.stringify(e));
  });

  // send a message to the server
  stream.write({
    lo: {
      latitude: 400000000,
      longitude: -750000000,
    },
    hi: {
      latitude: 420000000,
      longitude: -730000000,
    },
  });

  sleep(0.5);
};

You can just replace k6/net/grpc import with k6/experimental/grpc to use the new functionality. Documentation for the module is available here.

In the future, this functionality will be moved to the k6/net/grpc module.

You can now only upload a test to the cloud without running it #3030

For years users have wanted to be able to update the test that is saved in the cloud but not run it at this exact point.

This is now possible by adding --upload-only when invoking k6 cloud as in k6 cloud --upload-only script.js.

This is likely going to be most useful in a CI on the actual test script project. Now that CI can just run k6 cloud --upload-only new-version-of-script.js on "release".

And later on that newer version will be used. For example by a scheduled run.

Setting sample metadata API #3037

Support for high-cardinality metrics metadata was added in v0.41.0, but it wasn't accessible from test scripts. It's now possible to set or delete metadata for the whole VU with a similar API as used for tags:

import exec from "k6/execution";

export default () => {
  exec.vu.metrics.metadata["my_cool_id"] = "a very unique value";
  // all metrics from here on will have this metadata set
  delete exec.vu.metrics.metadata["my_cool_id"];
  // all metrics from here on will *not* have the metadata set
}

This also introduces the sub-object metrics on the vu object. Apart from metadata it has another property tags. This is meant to be the new way to set tags instead of using exec.vu.tags.

There are no current plans to replace exec.vu.tags with exec.vu.metrics.tags.

UX improvements and enhancements

  • #3099 replace "breached" with "crossed" in logs around thresholds. Thanks to @MattDodsonEnglish 🙇.
  • #3102 Better error message when SharedArray constructor is provided with an async function. This is not supported, but the original message wasn't very clear.
  • #3089 Add Software Bill of Materials (SBOM) reports to k6 releases. Thanks to @SadFaceSmith 🙇.
  • goja#510 JSON.parse will now fail with a friendlier error message.

Bug fixes

  • browser#852 Fix Locator.WaitFor for detached and hidden states.
  • browser#859 Fix remote object parsing when subtype is null.

Maintenance and internal improvements

  • #2991 Refactor JS modules system so that is usable in tests. Which allowed enabling the tc39 tests for modules #3040.
  • #3025 Internally stop referring to afero and use an internal package to do all file system interaction. That package still uses afero.
  • #3036 and #3053 Add options to scenarios for usage by browser module.
  • #3058 fix repetitive the. Thank you, @cuishuang 🙇.
  • #3064, #3070, #3075 and #3106 Go dependencies updates.
  • #3067 Add method to retrieve all registered metrics.
  • #3068 Add metric Sink constructor.
  • #3078 Pin base Docker builder image to Alpine 3.17. Thank you, @arukiidou 🙇.
  • #3086 Fix downloading .golangci.yml for PRs from forks.
  • #3088 Make TestDNSResolver less flaky.
  • #3094 Fix example from the run command. Thanks to @rocktwotj 🙇.
  • #3095 Maintenance update of .golangci.yml.
  • #3103 Fix lint and logical issues in k6/data module tests.
  • #3045, #3049, #3073 and #3044 New issues are now automatically assigned to maintainers, to improve response time on issues. Both new issue and new PR assignments are now not using external actions.
  • #3109 Add a way to get the cloudapi Client's base URL. Thanks to @yorugac 🙇.

Roadmap

We're excited to share our public roadmap, outlining the upcoming features and improvements we have planned.

We hope this updated roadmap provides a clear overview of our plans for k6's future development. As always, we welcome feedback, corrections, and suggestions to make this roadmap more comprehensive, accessible, and valuable for the k6 community.

Cloud output v2

Work on a new version of the cloud output has been ongoing over this cycle.

While functionally it is now mostly complete, we feel like more testing is still needed and some smaller issues need to be ironed out.

Over the next cycle we will be testing it internally, and in v0.46.0 it will be generally available as the default Cloud output. It will still be possible to use the current version via an option, but we plan to gradually deprecate it.

The new output has some benefits over the previous one:

  • Binary (protobuf) format instead of JSON #2963
  • Samples aggregation for every metric instead of only for HTTP ones #3071
  • HDR Histogram generation for trend-type metrics #3027

This in general makes the payload sent for tests with a lot of samples much smaller, which also in most cases has turned out to lower the CPU and memory usage.

Other related PRs: #3041, #3061, #3063, #3072, #3082, #3083, #3085, #3098, #3105

v0.44.1

11 months ago

k6 v0.44.1 is a patch release that fixes a couple of packaging issues:

  • #3055 due to an oversight, the k6 package signing key in our RPM repository wasn't updated when its expiration date was extended in March.
  • #3060 fixed building of Docker image due to a missing pinned ca-certificates version.

There are no functional changes in k6 compared to v0.44.0.

v0.44.0

1 year ago

k6 v0.44.0 is here! 🎉 This release includes:

  • A new k6/experimental/webcrypto module implementing (partially) the Web Crypto API specification.
  • A sampling option for the experimental tracing module.
  • Memory usage improvements.
  • Bug fixes and UX improvements.

Some highlights from the k6/experimental/browser module are:

  • locator.click is now asynchronous, which is a breaking change.
  • browserContext.addCookies has now been implemented.
  • browserType.Connect has been implemented so k6 can now connect to an already running Chrome/Chromium browser instance.
  • Web vitals are natively supported when working with the browser module.

Breaking changes

The browser module is still in an experimental stage, and therefore breaking changes are expected as we are improving the APIs to make them more user-friendly.

  • browser#790 Converted locator.click to async to have feature parity with page.click and elementHandle.click. Users must remember to work with promise.All and page.waitForNavigation() when a click action results in navigation.

    A locator.click action that doesn't result in navigation can be used like so:

    const tails = page.locator("input[value='Bet on tails!']");
await tails.click(),

    A locator.click action that does result in a navigation can be used like so:

    const tails = page.locator("input[value='Bet on tails!']");
await Promise.all([
  page.waitForNavigation(),
  tails.click(),
]);

  • browser#817 We've removed --no-sandbox from the default Chrome launch arguments. Now Chrome will launch with a sandbox, which is a more secure way of running the browser. If you are running tests under a root user, the browser will no longer launch unless the --no-sandbox argument is supplied. You can still pass this flag when launching a new Chrome instance using the args parameter on chromium.launch:

    const browser = chromium.launch({
  args: ['no-sandbox'],
});

  • browser#844 Removed the exported version param from the root module. Users should from now on reference the k6 version instead of the browser module version.

  • browser#838 Removed the first meaningful paint metric. This metric is being deprecated across all the browsers, because the metric's definition relies on browser-specific implementation details, and we've now introduced web vitals in the browser module which is a reliable industry standard way to measure frontend performance. You can find more details here.

  • browser#843 Removed the build step from Github Actions. From this release onwards, no new standalone browser binaries will be built and available from the releases section. The latest version of the browser module will be available in the k6 binary which can be found in the k6 releases page.

New features

A new k6/experimental/webcrypto module implementing the Web Crypto API specification #3007

This release includes a new k6/experimental/webcrypto module partially implementing the Web Crypto API specification in k6.

Expand to see an example of the new functionality.

This example shows encrypting and decrypting of a "Hello, World!" string using AES-CBC algorithm.

import { crypto } from 'k6/experimental/webcrypto';

export default async function () {
  const key = await crypto.subtle.generateKey(
    {
      name: 'AES-CBC',
      length: 256,
    },
    true,
    ['encrypt', 'decrypt']
  );

  const encoded = stringToArrayBuffer('Hello, World!');
  const iv = crypto.getRandomValues(new Uint8Array(16));

  const ciphertext = await crypto.subtle.encrypt(
    {
      name: 'AES-CBC',
      iv: iv,
    },
    key,
    encoded
  );

  const plaintext = await crypto.subtle.decrypt(
    {
      name: 'AES-CBC',
      iv: iv,
    },
    key,
    ciphertext
  );

  console.log(
    'deciphered text == original text: ',
    arrayBufferToHex(plaintext) === arrayBufferToHex(encoded)
  );
}

function arrayBufferToHex(buffer) {
  return [...new Uint8Array(buffer)].map((x) => x.toString(16).padStart(2, '0')).join('');
}

function stringToArrayBuffer(str) {
  var buf = new ArrayBuffer(str.length * 2); // 2 bytes for each char
  var bufView = new Uint16Array(buf);
  for (var i = 0, strLen = str.length; i < strLen; i++) {
    bufView[i] = str.charCodeAt(i);
  }
  return buf;
}

You can see the list of currently supported APIs and algorithms in the project's README. Documentation for the module is available here.

Add sampling capabilities to the experimental tracing module #2886

This release adds sampling capabilities to the tracing module. You can now specify a sampling rate with the sampling option when initializing a Client, or in the tracing.InstrumentHTTP function.

browserContext.addCookies browser#760

Cookies can now be added to a BrowserContext and all new Pages created from this context will have the cookie assigned to them. Thanks @zucchinho for implementing this feature!

const context = browser.newContext()
context.addCookies([{name: 'myCookie', value: 'hello world', url: 'https://test.k6.io'}])
const page = context.newPage()

browserType.Connect browser#800

There are cases where the user may want to connect to a remote browser instance where they have more control over the browser lifecycle, such as when working in a resource bound environment. This feature enables users to connect to a manually started Chrome/Chromium browser instance. It's a simple case of replacing browser.launch with browser.connect and supplying the CDP url as the first argument. Not all launch options will work with connect since the browser instance should already have started prior to working with connect. Since we assume that the user had decided to take ownership of starting the browser, we have made browser.close a NOOP when working with browser.connect, so the user will need to close the browser themselves.

const browser = chromium.connect('ws://127.0.0.1:1234/devtools/browser/e3bb7e53-ad0f-46f3-ae89-a8416868f4ce')
const page = browser.newPage();

Web Vitals are now natively supported by the browser module browser#836 browser#847

Web vitals are the defacto way for developers to measure their frontend performance using the core metrics:

  • Largest contentful paint (LCP)
  • First input delay (FID)
  • Cumulative layout shift (CLS)

These measurements are now calculated for all tests without any additional work from your side. Simply run your test as you have been doing and you will be presented with the new metrics in the output. This is the output after running the examples/fillform.js script:

webvital_cumulative_layout_shift..........: avg=0        min=0        med=0        max=0        p(90)=0        p(95)=0
webvital_cumulative_layout_shift_good.....: 1       0.323332/s
webvital_first_contentful_paint...........: avg=278.86ms min=141.1ms  med=229.39ms max=466.1ms  p(90)=418.76ms p(95)=442.43ms
webvital_first_contentful_paint_good......: 3       0.969995/s
webvital_first_input_delay................: avg=300µs    min=200µs    med=300µs    max=399.99µs p(90)=379.99µs p(95)=389.99µs
webvital_first_input_delay_good...........: 2       0.646663/s
webvital_interaction_to_next_paint........: avg=16ms     min=16ms     med=16ms     max=16ms     p(90)=16ms     p(95)=16ms
webvital_interaction_to_next_paint_good...: 1       0.323332/s
webvital_largest_content_paint............: avg=303.6ms  min=141.1ms  med=303.6ms  max=466.1ms  p(90)=433.6ms  p(95)=449.85ms
webvital_largest_content_paint_good.......: 2       0.646663/s
webvital_time_to_first_byte...............: avg=205.23ms min=104.79ms med=188.39ms max=322.5ms  p(90)=295.67ms p(95)=309.08ms
webvital_time_to_first_byte_good..........: 3       0.969995/s

You may have noticed other metrics in there too. We rely on the web-vitals JS library which exposes a few more metrics, so we've left them in for you to experiment with. You can find more details on all the browser module metrics in our documentation.

You will no longer see browser_first_contentful_paint in the summary, and instead you can work with webvital_first_contentful_paint.

UX improvements and enhancements

  • #2906 Added multiple date-time formats for CSV output. Thanks, @Azanul!
  • #2916 k6 started to show the actual binary's name in the usage help. Thanks, @ariasmn!
  • #2942 Reference 'k6 cloud' instead of 'Load Impact' in docs and errors.
  • #2985 Added support of async functions for setup and handleSummary.
  • #2901 Added a warning when the number of time series exceeds 100 000, which could lead to potential out-of-memory issues.
  • #2997 Added a new exit code (109), used on a go panic.
  • browser#788 Updated the browser readme to highlight that it is now a module in k6.
  • browser#803 Users are now warned if the browser.close method is called more than once.
  • browser#820 Added error handling to wildcard selectors, which cleans up the error output in the terminal.
  • browser#848 Multiple k6 instances can now connect to one browser to run concurrent tests. This update empowers high-concurrency browser testing with multiple VUs and instances. Using the new browserType.Connect API, users can now connect to an existing browser instance and execute concurrent tests, which was not possible previously.

Bug fixes

  • #2984 Fixed wrongly assigned HTTP POST and PUT methods for the tracing.instrumentHTTP. Thanks, @marcin-maciej-seweryn!
  • #2928 Handled a new behavior of filepath.Join on windows with go1.20, which could cause issues for the k6 archive and k6 cloud commands.
  • #2915 Fixed check that could return incorrect values for some cases with many preallocated VUs.
  • #2953 Fixed active VU reporting by arrival-rate executors.
  • #3006 xk6-websockets updated to v0.2.0 which fixes a lock up of the whole k6.
  • #3023 Fixed Trend.Max's support of negative values.
  • browser#781 Fixed mapping of response object's function from jSON to json.
  • browser#779 Cleared Zombie processes on panic.
  • browser#834 Fixed page.close so that it closes the current page and not the whole browser context.

Maintenance and internal improvements

Improved the per-VU buffer pool #2879

Improved the per-VU buffer pool which should greatly reduce memory usage, at a minor expense of higher CPU usage and lower request throughput. In some cases, this change can reduce memory usage up to 50%.

Thanks to @davidpst for the contribution!

Other minor changes in this release:

  • #3004 Changed eventloop.WaitOnRegistered to execute all scheduled callbacks.
  • #2881 Refactored how modules are loaded. This is a preparation for the upcoming ESM support.
  • #2920 Updated Go version that we use for k6 compilation to 1.20.x. The docker image is also updated to use alpine:3.17.
  • #2986 Refactored goja's isNullish to be a part of js/common.
  • #2960 Refactored sirupsen/logrus usage.
  • #2999 Directly embed lib.TestPreInitState in js/common.InitEnvironment.
  • #2892 Added z/OS build flags for IBM z/OS compatibility. Thanks, @msradam!
  • #2833 Fixed detected memory leaks.
  • #2931, #2940, #2895, #3002 Updated k6's dependencies. Added goja's generator support.
  • #2947, #2943, #2946, #3009, #3012, #2894 Tests' fixes, refactoring, and improvements.
  • #2891, #2921, #2923, #2990, #2995, #3016, #2989 Linters and formatting fixes.
  • #3005 The samples catalog was renamed to examples.
  • browser#776 Fixed a test for preset flags for Chrome on macOS.
  • browser#782, browser#783, browser#826 Fixed and refactored the Go-JS mapping.
  • browser#797, browser#832 Fixed multi browser close.
  • browser#796, browser#810 Refactored browserContext.SetExtraHTTPHeaders to work with errors and ErrFatal.
  • browser#798, browser#799 Added more tests for the Go-JS mapping layer.
  • browser#802 Added a helper to assert on the logs and dump the logs for easier debugging.
  • browser#807 Fixed incorrect keyboard key code on up/down key presses.
  • browser#819 Browser.Launch now transitions to Browser.Connect when a CDP URL is provided in an environment variable.
  • browser#821, browser#824, browser#830 Upgraded dependencies and fixed breaking changes.

v0.43.1

1 year ago

k6 v0.43.1 is a patch release containing a few bugfixes:

  • #2926 fixed a panic in setup() code when vu.iterationInScenario from k6/execution was used.
  • #2934 fixed a wrongly printed internal output ID to the stdout UI.
  • #2938 fixed a synchronization bug that caused k6 to get stuck after the end-of-test summary when sending the usage report took more than 3s. Thanks for reporting this, @ichasepucks!