Django + Docker + Postgres + ElasticSearch + Redis recipe

docker-compose.yml

version: '2'
services:
  web:
    build: .
    image: uzman
    command: python manage.py runserver 0.0.0.0:8000
    ports:
      - "3000:3000"
      - "8000:8000"
    volumes:
      - .:/code
    depends_on:
      - npm
      - sass
      - migration
      - db
      - redis
      - elasticsearch
  db:
    image: postgres:9.5.4
    volumes:
      - .:/tmp/data/
  npm:
    image: uzman
    command: npm install
    volumes:
      - .:/code
  elasticsearch:
    image: elasticsearch:2.4.0
    command: elasticsearch -Des.network.host=0.0.0.0
    ports:
      - "9200:9200"
      - "9300:9300"
  redis:
    image: redis:3.2.3
  sass:
    image: uzman
    command: gulp [principal task] #TODO: Add main task here
    volumes:
      - .:/code
  migration:
    image: uzman
    command: python manage.py migrate --noinput
    volumes:
      - .:/code

DockerFile

FROM python:3.5.2

RUN apt-get update \
    && apt-get install -y gettext curl sudo \
    && curl -sL https://deb.nodesource.com/setup_6.x | sudo -E bash - \
    && apt-get install -y nodejs \
    && apt-get install -y libpng-dev libtiff5-dev libjpeg62-turbo-dev zlib1g-dev \
        libfreetype6-dev liblcms2-dev libwebp-dev tcl8.6-dev tk8.6-dev python-tk \
        libopenjpeg-dev pngquant libmagickwand-dev imagemagick \
    && apt-get autoremove -y --purge \
    && rm -rf /var/lib/apt/lists/*

# WORKDIR /tmp/
# RUN wget https://nodejs.org/dist/v6.5.0/node-v6.5.0-linux-x64.tar.xz \
#     && tar xvf node-v6.5.0-linux-x64.tar.xz \
#     && cp -rp node-v6.5.0-linux-x64/* /usr/local/ \
#     && rm -rf node-v6.5.0-linux-x64.tar.xz node-v6.5.0-linux-x64/

# WORKDIR /usr/local/lib/

RUN mkdir /code
WORKDIR /code
RUN easy_install -U pip
RUN npm install -g autoprefixer gulpjs/gulp#4.0 node-sass susy # TODO: Verify in which folder packages are installed

ADD requirements.txt /code/requirements.txt
RUN pip install -r requirements.txt

Could you tell me what is the reasoning behind image: uzman on those services? thx.

it is my custom image for the app, when i use it in npm it means npm will use uzman as the base and it will handle it in other way.