背景介绍
项目开发过程中，客户环境大多是全内网环境，无法连接互联网。这样docker就不能yum在线联网安装，所需要的镜像也不能在线pull下载。
这时就需要进行离线安装docker及镜像。
下载docker安装文件
开始安装
解压：
tar -xvf docker-19.03.6.tar
cp 将解压出来的docker文件内容移动到 /usr/bin/ 目录下 ：
cp docker/* /usr/bin/
docker 注册为服务
创建配置文件
vim /etc/systemd/system/docker.service
内容参考： 补充配置文件 docker.service
重启 docker 服务
chmod +x /etc/systemd/system/docker.service #添加文件权限
systemctl daemon-reload #重载unit配置文件
systemctl start docker #启动Docker
systemctl enable docker.service
注意：如果你的服务已经启动，一定要先停止，否则启动失败，此时 systemctl start docker 无法停止，需要手动 kill掉
验证是否注册为服务
输入命令，观察效果
[root@host-10-227-50-187 system]# systemctl start docker
[root@host-10-227-50-187 system]# systemctl stop docker
[root@host-10-227-50-187 system]# docker ps
补充配置文件 docker.service
[root@host-10-227-50-187 system]# vim /etc/systemd/system/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
# BindsTo=containerd.service
# After=network-online.target firewalld.service containerd.service
After=network-online.target firewalld.service
Wants=network-online.target
# Requires=docker.socket
[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 -H fd:// --containerd=/run/containerd/containerd.sock
ExecStart=/usr/bin/dockerd
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
# Note that StartLimit* options were moved from "Service" to "Unit" in systemd 229.
# Both the old, and new location are accepted by systemd 229 and up, so using the old location
# to make them work for either version of systemd.
StartLimitBurst=3
# Note that StartLimitInterval was renamed to StartLimitIntervalSec in systemd 230.
# Both the old, and new name are accepted by systemd 230 and up, so using the old name to make
# this option work for either version of systemd.
StartLimitInterval=60s
# 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
# Comment TasksMax if your systemd version does not support it.
# Only systemd 226 and above support this option.
# TasksMax=infinity
# 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
[Install]
WantedBy=multi-user.target
~
~
~
~
~
"/etc/systemd/system/docker.service" 50L, 1767C 50,0-1 全部
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
# BindsTo=containerd.service
# After=network-online.target firewalld.service containerd.service
After=network-online.target firewalld.service
Wants=network-online.target
# Requires=docker.socket
[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 -H fd:// --containerd=/run/containerd/containerd.sock
ExecStart=/usr/bin/dockerd
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
# Note that StartLimit* options were moved from "Service" to "Unit" in systemd 229.
# Both the old, and new location are accepted by systemd 229 and up, so using the old location
# to make them work for either version of systemd.
StartLimitBurst=3
# Note that StartLimitInterval was renamed to StartLimitIntervalSec in systemd 230.
# Both the old, and new name are accepted by systemd 230 and up, so using the old name to make
# this option work for either version of systemd.
StartLimitInterval=60s
# 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
# Comment TasksMax if your systemd version does not support it.
# Only systemd 226 and above support this option.
# TasksMax=infinity
# 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
[Install]
WantedBy=multi-user.target