How to change dhcp/static IP on Ubuntu 18.04

For DHCP edit file /etc/netplan/50-cloud-init.yaml and change to:

network:

    ethernets:

        eth0:

            addresses: []

            dhcp4: true

            optional: true

    version: 2

For a static IP edit file /etc/netplan/50-cloud-init.yaml and change to:

network:

    ethernets:

        eth0:

            addresses:

            - 192.168.1.2/24

            gateway4: 192.168.1.1

            nameservers:

                addresses:

                - 1.1.1.1

                search:

                - domain.local

            optional: true

    version: 2

$ sudo netplan apply

$ sudo netplan try

That's it