Failed to start Docker Application Container Engine

$ sudo service docker restart
Redirecting to /bin/systemctl restart  docker.service
Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" f$
r details.

$ sudo systemctl status docker.service                                                                               
● docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/docker.service.d
           └─override.conf
   Active: failed (Result: start-limit) since 五 2017-07-14 11:31:35 CST; 11s ago
     Docs: https://docs.docker.com
  Process: 22799 ExecStart=/usr/bin/docker daemon --storage-driver=overlay --graph=/mnt/docker -H fd:// (code=exited, status=1/FAILURE)
 Main PID: 22799 (code=exited, status=1/FAILURE)

# 但是docker.service明明没有什么daemon。。。

[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

# 仔细看错误，发现
  Drop-In: /etc/systemd/system/docker.service.d
           └─override.conf
# 于是打开这个目录和文件，可以在上面找到那个错误命令
$ cat /etc/systemd/system/docker.service.d/override.conf 
[Service]
ExecStart=
ExecStart=/usr/bin/docker daemon --storage-driver=overlay --graph=/mnt/docker -H fd://

# 再看一下正常的默认的是怎么显示的。在另一台安装docker的机子上看,然后把上面的多余的删掉即可
$ cat  /etc/systemd/system/docker.service.d/override.conf 
[Service]
ExecStart=
ExecStart=/usr/bin/docker daemon -g /mnt/docker

$ sudo systemctl daemon-reload
$ sudo systemctl enable kubelet.service
Created symlink from /etc/systemd/system/multi-user.target.wants/kubelet.service to /usr/lib/systemd/system/kubelet.service.
$ sudo systemctl start kubelet.service
$ sudo systemctl enable kube-proxy.service
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-proxy.service to /usr/lib/systemd/system/kube-proxy.service.
$ sudo systemctl start kube-proxy.service

然后就可以了吧