Docker alpine + Rails + Postgresql

docker-compose.yml

version: '2'
services:
  db:
    image: postgres:9.6.5-alpine
  web:
    build: .
    # command: bin/rails s -p 3000 -b '0.0.0.0'
    command: ./scripts/start.sh
    ports:
      - "3000:3000"
    depends_on:
      - db
    volumes:
      - .:/app
    volumes_from:
      - box

  box:
    image: masterclass_backend
    volumes:
      - /box

Dockerfile

FROM ruby:2.4.1-alpine3.6

RUN apk add --update build-base libffi-dev libxml2-dev libxslt-dev postgresql-dev nodejs tzdata bash

ENV RAILS_ENV=production \
    APP_HOME=/app

ENV BUNDLE_PATH /box

RUN mkdir -p $APP_HOME
WORKDIR $APP_HOME

ADD . $APP_HOME

COPY Gemfile $APP_HOME/Gemfile
RUN touch $APP_HOME/Gemfile.lock

RUN bundle install