V0.22.0

v0.22.0 is here! :tada:

We're making an intermediary release before v1.0.0, as we wanted to get some changes out quicker. Thanks to @mohanprasaths for contributing to this release!

To see what's left for the v1.0.0 release, check out this milestone!

Also, have a look at our roadmap for what's up ahead, beyond the v1.0 release.

New Features!

• New JS API to set seed for PRNG. Now, you are able to set a seed to get reproducible (pseudo-)random numbers. (#677)

import {randomSeed} from "k6";

randomSeed(123456789);
let rnd = Math.random();
console.log(rnd)

• A new option --no-vu-connection-reuse lets users close HTTP keep-alive connections between iterations of a VU. (#676)
• You can now set the minimum and maximum sleep time at the end of an iteration with the new --min-sleep and --max-sleep HAR coverter CLI flags. (#694)
• Another new feature in the HAR converter enabled users to specify a JSON file with script options that would be added to the options of the generated scripts with the new --options flag. (#694)

UX

Automated deb, rpm, msi and nuget package builds (#675)

Previously we only had Homebrew releases for Mac and simple archives with plain binary releases for all other platforms. From now on, we'll also automatically build installation packages for Windows and rpm or deb based Linux distributions and upload them to bintray on every new release: https://bintray.com/loadimpact

For Debian-based Linux distributions, you have to do something like this to install k6:

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 379CE192D401AB61
echo "deb https://dl.bintray.com/loadimpact/deb stable main" | sudo tee -a /etc/apt/sources.list
sudo apt-get update
sudo apt-get install k6

And for rpm-based ones like Fedora and CentOS:

wget https://bintray.com/loadimpact/rpm/rpm -O bintray-loadimpact-rpm.repo
sudo mv bintray-loadimpact-rpm.repo /etc/yum.repos.d/
sudo yum install k6

For Windows you can download and install the latest .msi package or, if you use the chocolatey package manager, follow these instructions to set up the k6 repository.

Other UX improvements

• There's a new option to reset the saved cloud token: k6 login cloud --reset (#672)
• The check and group names in the summary at the end of a test now appear in the order they were defined. Thanks to @mohanprasaths for fixing this! (#674)

Internals

Real-time metrics (#678)

Previously most metrics were emitted only when a script iteration ended. With these changes, metrics would be continuously pushed in real-time, even in the middle of a script iteration. This should slightly decrease memory usage and help a lot with the aggregation efficiency of the cloud collector.

Portable builds (#658)

Before this, k6 builds that were done with just the standard Go language tools (i.e. go get, go build, etc.) were not portable because static resources like JS libraries had to be embedded in the binary after the build. Building fully portable binaries was done with the build-release.sh script (which used go.rice to bundle the static resources in the binary), but now that embedding is done beforehand and is committed in the git repo, so commands like go get/build/install produce fully-portable binary files without extra steps.

Bugs fixed!

• Metrics emitted by setup() and teardown() are not discarded anymore. They are emitted and have the implicit root group tag values of setup and teardown respectively (#678)
• Fixed a potential nil pointer error when the k6 cloud command is interrupted. (#682)

Breaking Changes

• The --no-connection-reuse option has been re-purposed and now disables keep-alive connections globally. The newly added --no-vu-connection-reuse option does what was previously done by --no-connection-reuse - it closes any open connections between iterations of a VU, but allows for reusing them inside of a single iteration. (#676)