Mix tasks to test and run on several nodes

Run tests in a distributed environment (cluster with several nodes).

The code is based on the distributed_test by Sam Schneider (credits!)

Usage

¡NB! empd must be started to use this functionality.

Use the default number of nodes (1 master + 4 slaves)

mix test.cluster

Use a specific number of nodes (1 master + n slaves). Note the master is not included in the count.

mix test.cluster --count 7

Setting up github action for CI

The project that uses test_cluster_task should have epmd started before running tests. This is a scaffold of how your GH Action might be configured (thanks to https://github.com/actions/setup-elixir)

name: Test

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    name: OTP ${{matrix.otp}} / Elixir ${{matrix.elixir}}
    strategy:
      matrix:
        otp: [21.3, 22.2]
        elixir: [1.9.4]
    steps:
      - uses: actions/checkout@v2
      - uses: actions/setup-elixir@v1
        with:
          otp-version: ${{matrix.otp}}
          elixir-version: ${{matrix.elixir}}
      - run: MIX_ENV=ci epmd -daemon
      - run: MIX_ENV=ci mix deps.get
      - run: MIX_ENV=ci mix test

Installation

If available in Hex, the package can be installed by adding test_cluster_task to your list of dependencies in mix.exs:

def deps do
  [{:test_cluster_task, "~> 0.3"}]
end