ubuntu 18.04 cloud-init networking

ubuntu18.04

[instead of /etc/network/interfaces]
/etc/netplan/*.yml
[IPV4 daemon]
systemctl status isc-dhcp-server.service
dpkg -l cloud-init

[install dhcp server]
apt-get install -y isc-dhcp-server

```yml
# netplan yaml sample
network:
    ethernets:
        enp0s3:
            addresses: []
            dhcp4: true
        enp0s8:
            addresses: [192.168.69.69/24]
            gateway4: 192.168.69.1
            nameservers:
                addresses: [8.8.8.8,8.8.4.4]
            dhcp4: no
    version: 2
```