Dockerized Elixir/Phoenix Development Environment

Introduction

I have been working on a long-running personal Phoenix project since Phoenix 1.0.2. Over the past year and a half or so, Phoenix and Elixir have undergone numerous changes, and some of them (okay most of them) broke my application code. Things really went south after I found myself working on multiple different projects that were built on different Phoenix versions. This reminded me a lot of the early Ruby and Rails days (and fighting rbenv and bundle).

This project was conceived to deal with the issues of running different Elixir and Phoenix versions and supporting the development of apps built with different Elixir and Phoenix versions.

New: Support for VS Code Remote Extension

After cloning this repository, open the folder in Visual Studio Code's Remote Extension to get a full Development Environment (with PostgreSQL Database) spun up automatically.

See https://code.visualstudio.com/docs/remote/containers for more details.

Getting Started

It's so simple: just clone this repository.

You can specify a particular Phoenix version by targeting the corresponding release tag of this repository.

For instance, for a dockerized development environment for Phoenix 1.6.0 you could run:

git clone -b v1.6.2 https://github.com/nicbet/docker-phoenix ~/Projects/hello-phoenix

New with Elixir 1.9: Releases

Follow this Github Gist to prepare a minimal Docker release image based on Alpine Linux (about 38MB for a Phoenix Webapp).

New Application from Scratch

Navigate the to where you cloned this repository, for example:

cd ~/Projects/hello-phoenix

Initialize a new phoenix application. The following command will create a new Phoenix application called

hello

src/

/app

./mix phx.new . --app hello

Why does this work? The

docker-compose.yml

src/

/app

/app

mix phoenix.new

NOTE: It is important to specify your app name through the

--app 

.

NOTE: It is okay to answer

Y

/app

NOTE: Starting from 1.3.0 the

mix phoenix.new

phx.new

phoenix.new

mix deps.get

Alternative: Existing Application

Copy your existing code Phoenix application code to the

src/

NOTE: the

src/

Database

Preparation

The

docker-compose.yml

db

db

Modify the Ecto configuration

src/config/dev.exs

# Configure your database
config :test, Test.Repo,
  adapter: Ecto.Adapters.Postgres,
  username: "postgres",
  password: "postgres",
  database: "test_dev",
  hostname: "db",
  pool_size: 10

Initialize the Database with Ecto

When you first start out, the

db

./mix ecto.create

If you copied an existing application, now would be the time to run your database migrations.

./mix ecto.migrate

Starting the Application

Starting your application is incredibly easy, you can either run:

docker-compose up

or

./mix phx.server

Once up, it will be available under http://localhost:4000.

You may need to update

config/dev.exs

0.0.0.0

config :hello_world, HelloWorldWeb.Endpoint,
  # Binding to loopback ipv4 address prevents access from other machines.
  # Change to `ip: {0, 0, 0, 0}` to allow access from other machines.
  http: [ip: {0, 0, 0, 0}, port: 4000],
  check_origin: false,
  code_reloader: true,
  debug_errors: true,
  secret_key_base: "rM/QJOrRiW+3WWLw+lHJ8kUFJK/LTrwakSG/ftGYl8jYN0FKqfgS50l2C9BdKMoK",
  watchers: [
    # Start the esbuild watcher by calling Esbuild.install_and_run(:default, args)
    esbuild: {Esbuild, :install_and_run, [:default, ~w(--sourcemap=inline --watch)]}
  ]

Notes

Executing custom commands

To run commands other than

mix

./run

./run iex -S mix