docker/docker.service

[Unit]
Description=Docker Application Container Engine
Documentation=http://docs.docker.com
After=network.target docker.socket
Requires=docker.socket

[Service]
# 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
EnvironmentFile=/etc/sysconfig/docker
ExecStart=/usr/bin/docker daemon -H fd:// $DOCKER_OPTS
MountFlags=slave
LimitNOFILE=1048576
LimitNPROC=1048576
LimitCORE=infinity
# set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes

[Install]
WantedBy=multi-user.target