Compox

Introduction

Compox ensure your whole infrastructure is up before running the tests.

Compox helps you to setup an ephemeral environment to run your tests using the docker-compose.yml present in your project. After all your tests are done, it will take the test environment down. This way your machine won't waste resources having the containers running when they are not needed.

Features

• Reuse created/running containers for other projects (e.g. shared database)
• Automatic start of the required container services
• Automatic stop of the required container services

Installation

Adding compox to your list of dependencies in mix.exs:

def deps do
  [
    {:compox, "~> 0.1.0-rc3", only: [:test]}
  ]
end

Usage

To use Compox follow these steps:

• Create a docker-compose.yml file with the containers that will be started by this application.

• Ensure Compox starts all containers before running the tests:

defp aliases do
  [
    test: ["compox.up", "ecto.create --quiet", "ecto.migrate --quiet", "test"]
  ]
end

• Edit your test_helper.exs to stop the containers after the tests are done:

ExUnit.after_suite(fn _ ->
  Compox.stop()
end)

Upchecks

Sometimes a container is started by it takes a while to be ready to be used by your application. For example, a database container can be started by the database will take few seconds to start accepting connections.

To avoid any errors, Compox supports upchecks probe configurations to validate whether a container can be used or not.

You can implement your own logic to validate if a container is ready (see example below) or use the default provided upchecks:

• Postgres: Compox.Upchecks.Postgrex

Example

Compox allows you to configure a project to start/stop the containers to run the tests, but also provides configuration to work with any kind of situation.

For example, some of or coworkers prefer to have the containers running all the time. In this case you want to ensure the docker containers are started before the test, so people that prefer to save resources will start the containers, but you will also won't to avoid to take containers down.

You config/test.exs file will look like:

use Mix.Config

config :compox,
  auto_start: true,
  auto_stop: false,
  exclude: ["a_service_should_not_be_started"],
  container_upchecks: [
    "postgres-service": {Compox.Upchecks.Postgrex, []},
    another_service: fn ->
      Another.Connection.up?()
    end
  ]

The people who will want to stop the containers after test can use a dotenv library to change the auto_stop config to true on their machines.

This can work the other way around, start/stopping the containers always and having dotfile config to skipping the start/stop.