Elixir Docker Template

This template contains the boilerplate to setup an Elixir application via Docker.

Motivation

As Elixir (as well as other languages) has different versions and prerequisites this template should help being able to have multiple versions at once. There are other ways like f.e. asdf to achieve this but for quickly checking out a project for instance Docker is a nice solution.

Further this should help to get other people onboarded more easily as the stack specifics are "hidden" by Docker.

Lastly the ability to develop under a production alike system environment might help to miss some hurdles.

Features

• Docker based environment for Elixir / Erlang
• Development script for easier handling of the stack

Prerequisites

You need to have the following installed:

• Docker for running the code
• Mutagen for code syncing (optional)

Mutagen is used to overcome the slow bind mounting on platforms like macOS. Note that the use of Mutagen is optional and will only be used if installed and the host machine is macOS. It can be enabled by providing USE_MUTAGEN=1 as shell env var (e.g. USE_MUTAGEN=1 ./dev start).

Usage

To use the template either download the files and augment an existing project or use this template as a starting point.

Per default the template does start an IEx session without anything else.

Init and create a mix project

To use the template for a mix based environment you can use the dev script by running:

./dev create mix new . --app my_app  # Create a mix app name `my_app`

After setting up the project you likely want to change the docker/app/run.sh script and execute iex -S mix instead of only iex.

The dev script

You can use the dev script to perform some common tasks like spinning up the stack.

To see the supported commands you can run:

$ ./dev

This will list all available commands. These can be easily extended by adding new functions to either the .dev directory or in the dev script itself. This is as well meant to be a starting point.

Customization of the Docker stack

The template has a fairly simple stack setup via Docker. But there are some commented lines that can be easily commented in to install f.e. the dependencies on container start as well as spawning a phx.server via the docker/app/run.sh script and/or add a database via the docker-compose.yml.

Renaming containers

You might want to adapt the naming of the Docker stack images like use something more meaningful than f.e. template-mutagen for the sync container. Please check and replace occurrences in the following file:

• docker-compose.yml

Setting up a Phoenix project

This is an example of what needs to be done additionally when setting up a Phoenix project.

• Set up the project via template
• Change the docker-compose.yml and comment in the DB container
• Adapt the docker/app/Dockerfile and comment in the Postgres client and phx_new part
• Adapt the docker/app/run.sh script
• Run ./dev create mix phx.new . --app app_name
  • Answer all question except the dependency installation with yes
• Stop the stack with ./dev clean
• Change the config/dev.exs and set the database hostname to db and the endpoint config to have http: [ip: {0, 0, 0, 0}, port: 4000],
• Start the project with ./dev start

License

MIT