FROM ubuntu:trusty
ENV VER 3.0.0
ENV TARBALL http://download.redis.io/releases/redis-$VER.tar.gz# ==> Install curl and helper tools...
RUN apt-get update
RUN apt-get install -y curl make gcc
# ==> Download, compile, and install...
RUN curl-L $TARBALL | tar zxv
WORKDIR redis-$VER
RUN make
RUN make install
#...# ==> Clean up...
WORKDIR /
RUN apt-get remove -y --auto-remove curl make gcc
RUN apt-get clean
RUN rm -rf /var/lib/apt/lists/* /redis-$VER
#...
CMD ["redis-server"]
结合注释，读起来并不困难，用到的都是常规的几个命令，简要介绍如下：
FROM：顶头写，指定一个基础镜像，此处基于 ubuntu:trusty
ENV：设置环境变量，这里设置了 VER 和 TARBALL 两个环境变量
RUN：最常用的 Dockerfile 指令，用于运行各种命令，这里调用了 8 次 RUN 指令
WORKDIR：指定工作目录，相当于指令 cd
CMD：指定镜像默认执行的命令，此处默认执行 redis-server 命令来启动 redis
执行构建：
$ docker build -t redis:lab-1.
注：国内网络，更新下载可能会较慢
查看大小：
动辄就有 300多 M 的大小，不能忍，下面我们开始一步步优化。
步骤 2: 优化基础镜像
方法：选用更小的基础镜像。
常用的 Linux 系统镜像一般有 ubuntu、centos、debian，其中debian 更轻量，而且够用，对比如下：
Including Red Hat® Enterprise Linux® / RHEL, CentOS and Fedora.
Node.js is available from the NodeSource Enterprise Linux and Fedora binary distributions repository. Support for this repository, along with its scripts, can be found on GitHub at nodesource/distributions.
Note that the Node.js packages for EL 5 (RHEL5 and CentOS 5) depend on the EPEL repository being available. The setup script will check and provide instructions if it is not installed.
Run as root on RHEL, CentOS or Fedora, for Node.js v6 LTS:
# CentOS-Base.repo
#
# This file uses a new mirrorlist system developed by Lance Davis for CentOS.
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-$releasever - Base
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
baseurl=http://mirrors.163.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever - Addons
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=addons
#baseurl=http://mirror.centos.org/centos/$releasever/addons/$basearch/
baseurl=http://mirrors.163.com/centos/$releasever/addons/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
#baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/
baseurl=http://mirrors.163.com/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
#baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/
baseurl=http://mirrors.163.com/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
