This guide covers configuring continuous integration pipelines for Elixir projects. If you’re new to Drone please read our Tutorial and build configuration guides first.

Build and Test

In the below example we demonstrate a pipeline that executes a series of mix commands. These commands are executed inside the Elixir Docker container, downloaded at runtime from DockerHub.

kind: pipeline
name: default

steps:
- name: test
  image: elixir:1.5
  commands:
  - mix local.rebar --force
  - mix local.hex --force
  - mix deps.get
  - mix test

Please note that you can use any Docker image in your pipeline from any Docker registry. You can use the official Elixir images, or your can bring your own.

Dependencies

If you decide to split your pipeline into multiple steps you need to make sure each step has access to project dependencies. Dependencies are downloaded to /root/.mix which is outside the shared workspace. Create a named volume to share this directory with all pipeline steps:

kind: pipeline
name: default

steps:
- name: install
  image: elixir:1.5
  volumes:
  - name: mix
    path: /root/.mix
  commands:
  - mix local.rebar --force
  - mix local.hex --force
  - mix deps.get

- name: test
  image: elixir:1.5
  volumes:
  - name: mix
    path: /root/.mix
  commands:
  - mix test

volumes:
- name: mix
  temp: {}

Test Multiple Versions

You can use Drone’s multi-pipeline feature to concurrently test against multiple versions of Elixir. This is equivalent to matrix capabilities found in other continuous integration systems.

---
kind: pipeline
name: elixir-1-5

steps:
- name: test
  image: elixir:1.5
  commands:
  - mix local.rebar --force
  - mix local.hex --force
  - mix deps.get
  - mix test

---
kind: pipeline
name: elixir-1-4

steps:
- name: test
  image: elixir:1.4
  commands:
  - mix local.rebar --force
  - mix local.hex --force
  - mix deps.get
  - mix test

...

If you find this syntax too verbose we recommend using jsonnet. If you are unfamiliar with jsonnet please read our guide.

local Pipeline(name, image) = {
  kind: "pipeline",
  name: name,
  steps: [
    {
      name: "test",
      image: image,
      commands: [
        "mix local.rebar --force",
        "mix local.hex --force",
        "mix deps.get",
        "mix test",
      ]
    }
  ]
};

[
  Pipeline("elixir-1-5", "elixir:1.5"),
  Pipeline("elixir-1-4", "elixir:1.4"),
]

Test Multiple Architectures

You can use Drone’s multi-pipeline feature to concurrently test your code on multiple architectures and operating systems.

---
kind: pipeline
name: test-on-amd64

platform:
  arch: amd64

steps:
- name: test
  image: elixir
  commands:
  - mix local.rebar --force
  - mix local.hex --force
  - mix deps.get
  - mix test

---
kind: pipeline
name: test-on-arm64

platform:
  arch: arm64

steps:
- name: test
  image: elixir
  commands:
  - mix local.rebar --force
  - mix local.hex --force
  - mix deps.get
  - mix test

...

If you find this syntax too verbose we recommend using jsonnet. If you are unfamiliar with jsonnet please read our guide.