Script to change hostname and write network configuration for a Ubuntu 22.04 VM guest on an OVH dedicated server

prep.sh

#!/bin/bash

# Setup OVH VM guest networking on Ubuntu 22.04

# Change hostname
read -p "Enter new fully-qualified domain name: "  fqdn
hostname=${fqdn%%.*}
echo "Changing FQDN to $fqdn, hostname to $hostname"
sudo hostnamectl set-hostname $hostname
sudo sed -i "s/\(^127\.0\.1\.1.*$\)/127.0.1.1\t$fqdn $hostname/g" /etc/hosts


# Configure IP addresses
read -p "Enter IPv4 address: "  ipv4addr
read -p "Enter IPv4 gateway (xxx.yyy.zzz.254 of the host): "  ipv4gateway
read -p "Enter IPv6 address: "  ipv6addr
read -p "Enter IPv6 gateway: (gggg:hhhh:iiii:jjff:ff:ff:ff:ff of the host) "  ipv6gateway

echo "Writing new IP address configurations"
sudo bash -c "cat > /etc/netplan/01-dt-setup.yaml" <<EOL
network:
  version: 2
  ethernets:
    eth0:
      dhcp4: false
      optional: false
      addresses:
        - $ipv4addr/32
        - $ipv6addr/64
      routes:
        - to: default
          via: $ipv4gateway
          on-link: true
        - to: default
          via: $ipv6gateway
          on-link: true
      nameservers:
        addresses:
          - 8.8.8.8
          - 1.1.1.1
    eth1:
      dhcp4: true
      dhcp4-overrides:
        use-routes: false

EOL
sudo chmod 600 /etc/netplan/01-dt-setup.yaml
echo "Removing existing cloud-init configuration"
sudo rm /etc/netplan/50-cloud-init.yaml
sudo bash -c "echo \"network: {config: disabled}\" > /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg"
echo "Applying network config"
sudo netplan apply

# Resize filesystem
echo "Resizing partition"
sudo growpart /dev/sda 2
echo "Resizing filesystem"
sudo resize2fs /dev/sda2

echo "Done - suggested to reboot"

#10 maybe handy

#28 #29 just wrong? How are you dealing with your subnet mask / bit count??
I am on phone so might have missed something?