elixir and phoenixframework with docker-compose

docker-compose.yml

# docker-compose up -d
# docker-compose exec dev bash
# mix phx.new new_project
# in new_project/config/dev.exs replace hostname: "localhost" to hostname: "db",
# cd new_project && mix ecto.create && mix phx.server
version: '3'
services:
  dev:
    build:
        context: .
        dockerfile: Dockerfile
    volumes:
        - .:/code
    ports:
        - 4000:4000
    stdin_open: true
    tty: true
    depends_on:
      - db

  db:
    image: postgres
    restart: always
    environment:
      POSTGRES_PASSWORD: postgres

volumes:
    phoenix_code:

Dockerfile

FROM elixir:slim

# install Node.js (>= 8.0.0) and NPM in order to satisfy brunch.io dependencies
# See https://hexdocs.pm/phoenix/installation.html#node-js-5-0-0
RUN apt-get update -y && \
    apt-get install -y curl git && \
    curl -sL https://deb.nodesource.com/setup_13.x | bash - && \
    apt-get install -y inotify-tools nodejs

WORKDIR /code

RUN useradd -c 'phoenix user' -m -d /home/pho -s /bin/bash pho && \
    chown -R pho.pho /code
USER pho

# install the Phoenix Mix archive
RUN mix local.hex --force && \
    mix local.rebar --force && \
    mix archive.install hex phx_new --force

ENV HOME /home/pho