systemctl cat nfs-server
# /usr/lib/systemd/system/nfs-server.service
[Unit]
Description=NFS server and services
DefaultDependencies=no
Requires= network.target proc-fs-nfsd.mount
Requires= nfs-mountd.service
Wants=rpcbind.socket
Wants=rpc-statd.service nfs-idmapd.service
Wants=rpc-statd-notify.service

After= local-fs.target
After= network.target proc-fs-nfsd.mount rpcbind.socket nfs-mountd.service
After= nfs-idmapd.service rpc-statd.service
Before= rpc-statd-notify.service

# GSS services dependencies and ordering
Wants=auth-rpcgss-module.service
After=rpc-gssd.service gssproxy.service rpc-svcgssd.service

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStartPre=/usr/sbin/exportfs -r
ExecStart=/usr/sbin/rpc.nfsd
ExecStop=/usr/sbin/rpc.nfsd 0
ExecStopPost=/usr/sbin/exportfs -au
ExecStopPost=/usr/sbin/exportfs -f

ExecReload=/usr/sbin/exportfs -r

[Install]
WantedBy=multi-user.target