kubespray/roles/docker/templates/docker.service.j2

[Unit]
Description=Docker Application Container Engine
Documentation=http://docs.docker.com
{% if ansible_os_family == "RedHat" %}
After=network.target docker-storage-setup.service
Wants=docker-storage-setup.service
{% elif ansible_os_family == "Debian" %}
After=network.target docker.socket
Wants=docker.socket
{% endif %}

[Service]
Type=notify
Environment=GOTRACEBACK=crash
ExecReload=/bin/kill -s HUP $MAINPID
Delegate=yes
KillMode=process
ExecStart=/usr/bin/docker daemon \
          $DOCKER_OPTS \
          $DOCKER_STORAGE_OPTIONS \
          $DOCKER_NETWORK_OPTIONS \
          $INSECURE_REGISTRY
TasksMax=infinity
LimitNOFILE=1048576
LimitNPROC=1048576
LimitCORE=infinity
TimeoutStartSec=1min
Restart=on-abnormal

[Install]
WantedBy=multi-user.target