Docker compose: elixir-node@ubuntu + postgres@alpine

docker-compose.yml

version: '2.1'

services:
  db:
    image: postgres:alpine
    ports:
      - "8081:5432"
    environment:
      - POSTGRES_PASSWORD=postgres

  web:
    build: .
    ports:
      - "8080:8080"
    links:
      - "db:database"
    depends_on:
      - db
    restart: always

Dockerfile

FROM elixir:1.5

EXPOSE 8080 
ENV PORT=8080 MIX_ENV=prod
ENV LANG=C.UTF-8

RUN apt-get update && mix local.hex --force && mix local.rebar --force

# Install node.js and Elm
RUN curl -sL https://deb.nodesource.com/setup_8.x \
    | bash - && apt-get install -y nodejs openssl \
    && rm -rf /var/lib/apt/lists/* \
    && npm i -g yarn \
    && npm install -g elm --unsafe-perm=true --allow-root

# Cache Elm deps
ADD assets/elm/elm-package.json ./assets/elm/elm-package.json
RUN cd assets/elm && elm-package install --yes && cd ../..
 
# Cache Elixir deps
ADD mix.exs mix.lock ./
RUN mix do deps.get, deps.compile

# Cache npm deps
ADD assets/package.json assets/package.json
RUN cd assets && yarn && cd ..

ADD . .

WORKDIR .
ENTRYPOINT mix do ecto.create, ecto.migrate, phx.server