stephenmoloney/alpine-elixir-phoenix

An Alpine Linux base image containing Elixir, Erlang, Node, Hex, and Rebar. Ready for Phoenix applications!

Elixir/Phoenix on Alpine Linux

This Dockerfile provides everything you need to run your Phoenix application in Docker out of the box.

It is based on my alpine-erlang image, and installs Elixir (1.6.4), Node.js (6.10.x), Hex and Rebar. It can handle compiling your Node and Elixir dependencies as part of it's build.

Usage

NOTE: This image is intended to run in unprivileged environments, it sets the home directory to /opt/app, and makes it globally read/writeable. If run with a random, high-index user account (say 1000001), the user can run an app, and that's about it. If run with a user of your own creation, this doesn't apply (necessarily, you can of course implement the same behaviour yourself). It is highly recommended that you add a USER default instruction to the end of your Dockerfile so that your app runs in a non-elevated context.

To boot straight to a prompt in the image:

$ docker run --rm -it --user=1000001 bitwalker/alpine-elixir-phoenix iex
Erlang/OTP 20 [erts-9.1.3] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:10] [hipe] [kernel-poll:false]

Interactive Elixir (1.6.4) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)>

Extending for your own application:

FROM bitwalker/alpine-elixir-phoenix:latest

# Set exposed ports
EXPOSE 5000
ENV PORT=5000 MIX_ENV=prod

# Cache elixir deps
ADD mix.exs mix.lock ./
RUN mix do deps.get, deps.compile

# Same with npm deps
ADD assets/package.json assets/
RUN cd assets && \
    npm install

ADD . .

# Run frontend build, compile, and digest assets
RUN cd assets/ && \
    npm run deploy && \
    cd - && \
    mix do compile, phx.digest

USER default

CMD ["mix", "phx.server"]

It is recommended when using this that you have the following in .dockerignore when running docker build:

_build
deps
assets/node_modules
test

This will keep the payload smaller and will also avoid any issues when compiling dependencies.

License

MIT