...
RUN apt-get update && apt-get install -y --no-install-recommends libjemalloc1 && rm -rf /var/lib/apt/lists/*

RUN apt-get update \
	&& apt-get install -y cassandra="$CASSANDRA_VERSION" \
	&& rm -rf /var/lib/apt/lists/*
...

...
RUN apk add --update --no-cache \
    python \
    python-dev \
    py-pip \
    build-base \
  && pip install virtualenv \
  && rm -rf /var/cache/apk/*
...

FROM
MAINTAINER

ENV FRESHED_AT 2017-01-17
# set timezone if possible
RUN ln -f -s /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

deb http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse

apt-get install python-setuptools
easy_install supervisor

RUN echo "deb http://repos.mesosphere.io/ubuntu/ trusty main" > /etc/apt/sources.list.d/mesosphere.list && \
    apt-key adv --keyserver keyserver.ubuntu.com --recv E56151BF

apt-get install openjdk-7-jre

sudo apt-get autoclean（已卸载软件的安装包）
sudo apt-get clean（未卸载软件的安装包）类似于 rm -rf /var/cache/apt/archives/*
sudo apt-get autoremove （清理系统不再需要的孤立的软件包）

apt-get install -y --no-install-recommends vim

RUN apt-get install -y curl && \
    curl -fL http://apache.fayea.com/zookeeper/zookeeper-3.3.6/zookeeper-3.3.6.tar.gz | tar xzf - -C /usr/local && \
    mv /usr/local/zookeeper-3.3.6 /usr/local/zookeeper