mkdir -p /etc/systemd/system/docker.service.d/

cat << EOF > /etc/systemd/system/docker.service.d/startup_options.conf
# /etc/systemd/system/docker.service.d/override.conf
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd -H fd:// -H tcp://0.0.0.0:2376 
EOF