Elixir-K6

Quick and painless load testing for Elixir applications. Generate and run load tests via a local installation of k6.

Originally developed at SpawnFest 2021.

Installation

The package can be installed by adding k6 to your list of dependencies in mix.exs:

def deps do
  [
    {:k6, "~> 0.2.1"}
  ]
end

Usage

To generate new k6 tests run:

mix k6.gen.test <test_name>

By default k6 tests will be placed under the priv/k6 directory of your project.

The template to use for the test can be set via the --type argument. Supported types are rest (default), graphql, grpc, websocket, phoenix-channel (experimental) and liveview (experimental).

Run mix help k6.gen.test for more info on generating tests.

To execute k6 tests run:

mix k6 run <test_name>.js

Run mix help k6 for more info on running k6.

Configuration

elixir-k6 can be configured via config.exs as follows:

config :k6,
  version: "vX.Y.Z",
  env: [VAR_KEY: "some value"],
  workdir: "priv/my_load_tests_dir"

The supported configuration parameters are:

• version: the desired version of k6. Defaults to v0.39.0.
• env: environment variables to pass to load tests. K6 will expose those variables to load test scripts within the __ENV object.
• workdir: path of the directory that contains k6 load tests. Relative to the project, defaults to priv/k6.

K6 installation

K6 is automatically installed the first time you run k6 tests, and it is stored in _build/k6. In case you want to explicitly install it before running any test, you can run mix k6.install.

At the moment the following architectures are supported:

OS	Architecture
MacOs	amd64
MacOs	arm64 (not tested)
Linux	amd64
Linux	arm64 (not tested)

By default the installation task will install k6 version v0.39.0. You can override this in your config file, as documented above.

Contributing

Issues and contributions are welcome!

To run static analysis run:

mix check

To execute tests run:

mix test

The test suite also includes some end-to-end tests, which are not executed by default as they are much slower. To execute all tests run:

mix test --include end_to_end