docker安装docker.service lacks both ExecStart= and ExecStop= setting. Refusing.

离线安装docker的时候遇到了这个问题
报错：
Failed to start docker.service: Unit is not loaded properly: Invalid argument.
docker.service lacks both ExecStart= and ExecStop= setting. Refusing.

原因是我看的教程里让我修改的是/usr/lib/systemd/system/下面的docker.service，但实际上改了这个检测不到，真正要改的是/etc/systemd/system/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 --selinux-enabled=false --insecure-registry=127.0.0.1
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

改好之后，

• systemctl daemon-reload
• systemctl start docker
• systemctl enable docker.service
• systemctl status docker
• docker -v
  即可