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
EnvironmentFile=-/etc/sysconfig/docker
EnvironmentFile=-/etc/sysconfig/docker-storage
EnvironmentFile=-/run/docker/runtimes.env
#ExecStartPre=/bin/mkdir -p /run/docker
#ExecStartPre=/usr/libexec/docker/docker-setup-runtimes.sh
# 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 $OPTIONS $DOCKER_STORAGE_OPTIONS $DOCKER_ADD_RUNTIMES
ExecStart=/usr/bin/dockerd $OPTIONS -H=tcp://0.0.0.0:2376 $DOCKER_STORAGE_OPTIONS $DOCKER_ADD_RUNTIMES

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