0. 检查卸载已有docker
查看是否安装 docker yum list installed | grep docker
卸载docker yum remove docker docker-common container-selinux docker-selinux docker-engineyum remove -y docker-*
1. 下载安装包
要下载docker-18.06.x-ce版本，否则有些不支持 k8s。。请看版本支持 https://rancher.com/docs/rancher/v1.6/en/hosts/#supported-docker-versions
docker-18.06.x-ce下载地址 https://download.docker.com/linux/static/stable/x86_64/docker-18.06.3-ce.tgz
2. 安装docker
解压 tar zxvf docker-18.06.3-ce.tgz
将解压出来的docker文件内容移动到 /usr/bin/ 目录下 cp docker/* /usr/bin/
将docker注册为service服务 vim /etc/systemd/system/docker.service
编辑内容为：
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target
[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd
ExecReload=/bin/kill -s HUP $MAINPID
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
# Uncomment TasksMax if your systemd version supports it.
# Only systemd 226 and above support this version.
#TasksMax=infinity
TimeoutStartSec=0
# set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes
# kill only the docker process, not all processes in the cgroup
KillMode=process
# restart the docker process if it exits prematurely
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s
[Install]
WantedBy=multi-user.target
加权限 chmod +x /etc/systemd/system/docker.service
3. 启动docker，查看结果
启动docker
systemctl daemon-reload && systemctl start docker && systemctl enable docker.service
systemctl daemon-reload #重新加载daemon
systemctl start docker #启动Docker
systemctl enable docker.service #设置开机自启
查看状态 systemctl status docker
docker版本 docker version
4. 修改配置文件
修改docker数据默认存储地址：
首先在/home下创建 /data/docker，用于存储docker的镜像和数据 mkdir -p /home/data/docker
docker镜像和数据默认存储在 /var/lib/docker 中，
修改 /etc/docker/daemon.json ，vim /etc/docker/daemon.json，没有这个文件，会自动创建
修改内容如下（使用国内阿里云docker镜像库【详解请再往下看】，路径为刚刚创建的目录）：
{
"registry-mirrors": ["https://7bezldxe.mirror.aliyuncs.com/"],
"graph":"/home/data/docker"
}
关于registry-mirrors：
其中registry-mirrors是我使用的阿里云镜像加速服务，这个地址是不相同的。
浏览器进入 阿里云（www.aliyun.com）
在上边的搜索框中搜索 镜像加速服务 ，点击进入“官方镜像加速-容器镜像服务”
左侧点击 “快速入门”- “官方镜像加速”
点击“容器镜像服务控制台”
点击左侧 “镜像中心”- “镜像加速器”
可以看到url地址，将上述registry-mirrors地址替换掉即可
保险起见，重加载配置文件 重启docker
systemctl daemon-reload && systemctl restart docker
5. 验证
查看信息
docker info
Docker Root Dir 默认路径
