Dockerfile along with docker-compose.yml for a typical phoenix 1.3 elixir application

docker-compose.yml

version: '2'
services:
  db-data:
    image: postgres
    command: /bin/true
  db:
    image: postgres
    volumes_from:
      - db-data
    environment:
      POSTGRES_USER: elichat
      POSTGRES_PASSWORD: "your_password"
  web-data:
    image: busybox
    volumes:
      - /app/priv/static/uploads
  web:
    build: .
    volumes_from:
      - web-data
    volumes:
      - ./prod.secret.exs:/app/config/prod.exs:ro
    ports:
      - "4000:4000"
    depends_on:
      - db
    restart: always

Dockerfile

FROM elixir:1.5
MAINTAINER Sergiy Kukunin <sergey.kukunin@gmail.com>

RUN wget -qO- https://deb.nodesource.com/setup_8.x | bash - && \
    apt-get install -y nodejs
RUN mix local.rebar
RUN mix local.hex --force

WORKDIR /app
ENV MIX_ENV prod

ADD mix.exs /app/mix.exs
ADD mix.lock /app/mix.lock
RUN mix do deps.get, deps.compile

ADD assets/package.json /app/assets/package.json
ADD assets/package-lock.json /app/assets/package-lock.json
RUN cd assets && npm install

ADD . /app
RUN cd assets && npm run deploy

CMD mix do phx.digest, phx.server