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K6

Since v0.26.0

Introduction

The Testcontainers module for K6.

Using k6 extensions

This module takes advantage of k6x to dynamically build a k6 binary with all the k6 extensions required by the test script.

Adding this module to your project dependencies

Please run the following command to add the K6 module to your Go dependencies:

go get github.com/testcontainers/testcontainers-go/modules/k6

Usage example

ctx := context.Background()

// create a container with the httpbin application that will be the target
// for the test script that runs in the k6 container
gcr := testcontainers.GenericContainerRequest{
    ProviderType: testcontainers.ProviderDocker,
    ContainerRequest: testcontainers.ContainerRequest{
        Image: "kennethreitz/httpbin",
        ExposedPorts: []string{
            "80",
        },
        WaitingFor: wait.ForExposedPort(),
    },
    Started: true,
}
httpbin, err := testcontainers.GenericContainer(ctx, gcr)
defer func() {
    if err := testcontainers.TerminateContainer(httpbin); err != nil {
        log.Printf("failed to terminate container: %s", err)
    }
}()
if err != nil {
    log.Printf("failed to start container: %s", err)
    return
}

httpbinIP, err := httpbin.ContainerIP(ctx)
if err != nil {
    log.Printf("failed to get container IP: %s", err)
    return
}

import { check } from 'k6';
import http from 'k6/http';

export default function () {
  const res = http.get(`http://${__ENV.HTTPBIN}/status/200`);

  check(res, {
    'is status 200': (r) => r.status === 200,
  });
}

// run the httpbin.js test scripts passing the IP address the httpbin container
k6, err := k6.Run(
    ctx,
    "szkiba/k6x:v0.3.1",
    k6.WithCache(),
    k6.WithTestScript(absPath),
    k6.SetEnvVar("HTTPBIN", httpbinIP),
)
defer func() {
    cacheMount, err := k6.CacheMount(ctx)
    if err != nil {
        log.Printf("failed to determine cache mount: %s", err)
    }

    var options []testcontainers.TerminateOption
    if cacheMount != "" {
        options = append(options, testcontainers.RemoveVolumes(cacheMount))
    }

    if err = testcontainers.TerminateContainer(k6, options...); err != nil {
        log.Printf("failed to terminate container: %s", err)
    }
}()
if err != nil {
    log.Printf("failed to start container: %s", err)
    return
}

Module Reference

Run function

Info

The RunContainer(ctx, opts...) function is deprecated and will be removed in the next major release of Testcontainers for Go.

The K6 module exposes one entrypoint function to run the K6 container, and this function receives three parameters:

func Run(ctx context.Context, img string, opts ...testcontainers.ContainerCustomizer) (*K6Container, error)
  • context.Context, the Go context.
  • string, the Docker image to use.
  • testcontainers.ContainerCustomizer, a variadic argument for passing options.

Image

Warning

The K6 module uses a k6x image to build a k6 binary with all the required extensions. Therefore, only the szkiba/k6x image should be used with this module.

Use the second argument in the Run function to set a valid Docker image. In example: Run(context.Background(), "szkiba/k6x:v0.3.1").

Container Options

When starting the K6 container, you can pass options in a variadic way to configure it.

SetEnvVar

SetEnvVar sets an environment variable for the test script using the '--env' command-line flag in the k6 command in the container.

k6.New(ctx, k6.SetEnvVar("URL","test.k6.io"), k6.WithTestScript("/tests/test.js"))

WithCache

Use WithCache sets a volume to be used as cache for building the k6 binary inside the k6 container. This option improves considerably the execution time of test suites that creates multiple k6 test containers.

By default, a new volume is created and automatically removed when the test session ends.

This is convenient for example for CI/CD environments. In other cases, such as local testing, it can be convenient to reuse the same cache volume across test sessions. In this case, the TC_K6_BUILD_CACHE environment variables can be used to provide the name of a volume to be used and kept across test sessions. If this volume does not exist, it will be created.

k6.New(ctx, WithCache(), k6.WithTestScript("/tests/test.js"))

WithCmdOptions

Use WithCmdOptions to pass a variadic list of strings as options to the k6 run command

k6.New(ctx, testcontainers.WithCmdArgs("--vus=10", "--duration=30s"), k6.WithTestScript("/tests/test.js"))

WithTestScript

Use the WithTestScript option to specify the test script to run. The path to the script must be an absolute path. This option copies the script file to the container and pass it to k6's run command. At least one WithTestScript or WithRemoteTestScript option must be specified.

k6.New(ctx, k6.WithTestScript("/tests/test.js"))

WithRemoteTestScript

Use the WithRemoteTestScript option to specify the remote test script to run. The path to the remote script must be a http or https url. Basic authentication is supported. This option performs a HTTP GET to copy the remote file locally then copies the script file to the container and pass it to k6's run command. The default timeout for the GET is 60 seconds. Only javascript, or more specifically Content-Type:text/javascript is supported. At least one WithTestScript or WithRemoteTestScript option must be specified.

scriptUrl:="https://raw.githubusercontent.com/testcontainers/testcontainers-go/main/modules/k6/scripts/pass.js"

uri, _ := url.Parse(scriptUrl)
desc := k6.DownloadableFile{Uri: *uri , DownloadDir: t.TempDir()}
options := k6.WithRemoteTestScript(desc)

k6.New(ctx, k6.WithCache(), options)

The following options are exposed by the testcontainers package.

Basic Options

Lifecycle Options

Files & Mounts Options

Build Options

Logging Options

Image Options

Networking Options

Advanced Options

Experimental Options

Container Methods

The K6 container does not expose any method.