[Unit]
Description=Docker Application Container Engine
Documentation=http://docs.docker.com
After=network.target lvm2-monitor.service firewalld.service
# We don't use the docker socket activation, but doing this ensures that the
# docker.socket unit is alive while Docker is (docker.socket has BindsTo, so we
# only need a weak requirement to make sure starting docker.service also
# "starts" the socket service). Forcefully stopping docker.socket will not
# cause docker to die, but there's no nice workaround for that.
Wants=docker.socket

[Service]
EnvironmentFile=/etc/sysconfig/docker

# While Docker has support for socket activation (-H fd://), this is not
# enabled by default because enabling socket activation means that on boot your
# containers won't start until someone tries to administer the Docker daemon.
Type=notify
ExecStart=/usr/bin/dockerd --add-runtime oci=/usr/sbin/runc $DOCKER_OPTS
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=1048576
LimitNPROC=infinity
LimitCORE=infinity

# Uncomment TasksMax if your systemd version supports it.
# Only systemd 226 and above support this property.
TasksMax=infinity

# Set delegate yes so that systemd does not reset the cgroups of docker containers
# Only systemd 218 and above support this property.
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