一、在线安装
1、yum 包更新到最新
yum update
2、安装需要的软件包， yum-util 提供yum-config-manager功能，另外两个是devicemapper驱动依赖的
yum install -y yum-utils device-mapper-persistent-data lvm2
3、 设置yum源
yum-config-manager --add-repo download.docker.com/linux/cento…
4、 安装docker，出现输入的界面都按 y
yum install -y docker-ce
5、 查看docker版本，验证是否验证成功
docker -v
二、离线安装
1、下载docker 压缩包 如：
docker-20.10.12.tgz
2、制作安装脚本文件 ，创建一个install.sh文件，输入下边的代码（制作sh文件，要使用nodepad++从utf编码格式转化成uinx编码）
#!/bin/sh
echo '解压tar包...'
tar -xvf $1
echo '将docker目录移到/usr/bin目录下...'
cp docker/* /usr/bin/
echo '将docker.service 移到/etc/systemd/system/ 目录...'
cp docker.service /etc/systemd/system/
echo '添加文件权限...'
chmod +x /etc/systemd/system/docker.service
echo '重新加载配置文件...'
systemctl daemon-reload
echo '启动docker...'
systemctl start docker
echo '设置开机自启...'
systemctl enable docker.service
echo 'docker安装成功...'
docker -v
3、制作docker.service，创建docker.service文件，输入下边代码
docker.service
[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
4、制作卸载文件，创建一个uninstall.sh文件，输入下边代码
#!/bin/sh
echo '删除docker.service...'
rm -f /etc/systemd/system/docker.service
echo '删除docker文件...'
rm -rf /usr/bin/docker*
echo '重新加载配置文件'
systemctl daemon-reload
echo '卸载成功...'
将install.sh docker.service 安装包放到一个文件夹下
5、执行启动命令
sh install.sh <docker文件名称>
sh install.sh docker-20.10.12.tgz
