centos7.x docker安装及配置，持续更新

1. 安装docker-ce [root]，ce为docker社区版，免费，ee版为企业版，收费

列出所有已安装docker

 # rpm -qa | grep docker

删除已安装docker

 # rpm -e rpmname

安装docker-ce

 # yum install docker-ce.x86_64 # 此命令会自动安装相关依赖包

配置Daocloud加速

 # curl -sSL https://get.daocloud.io/daotools/set_mirror.sh | sh -s http://8ad7943c.m.daocloud.io

2. 开启dock服务，并设置开机自启 [root]

 # systemctl start docker
 # systemctl enable docker.service

3. 测试docker [root]

 # docker run hello-world # 会弹出如下信息，说明安装成功

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 . The Docker client contacted the Docker daemon.
 . The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (amd64)
 . The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 . The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://cloud.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/engine/userguide/

 # docker info #此命令可以查看dock内image和container信息

4. 使特定普通用户可以执行dock命令 [root]

 # visudo

在最下方加入此行，此行会允许特定用户以sudo方式运行docker，第一次运行时要求输入该特定用户的密码，以后每隔5分钟重复运行docker命令时需要输入密码：

 #docker
 username        ALL=(ALL)        /usr/bin/docker

下面这行的区别在于，不需要输入sudo密码，但是并不安全

 #docker
 username        ALL=(ALL)      NOPASSWD: /usr/bin/docker

设置/usr/bin/docker别名

 # alias docker="sudo /usr/bin/docker" 

直接在命令行输入上述命令时，此命令不会永久生效，如果想永久生效，将其加入对应用户的.bashrc中即可

 vim ~/.bashrc

 # .bashrc

 # User specific aliases and functions

 alias rm='rm -i'
 alias cp='cp -i'
 alias mv='mv -i'
 alias docker="sudo /usr/bin/docker"

 # Source global definitions
 if [ -f /etc/bashrc ]; then
         . /etc/bashrc
 fi
 ...

5. 测试 [username]

配置完上述命令之后，指定的普通用户就可以直接运行docker命令了

 # dock info

参考自：

http://cloud.51cto.com/art/201508/488478.htm

http://www.jianshu.com/p/e9b6f5a6f198

https://segmentfault.com/a/1190000007875949