Setup Netplan with WiFi settings on Ubuntu

setup-wifi-netplan-ubuntu.sh

#!/usr/bin/env bash
# Setup Netplan with WiFi settings on Ubuntu
# This should be copied to the target system with Rpi Imager etc.
# Usage: sudo setup-wifi-netplan-ubuntu.sh --ssid <SSID> --password <PASSWORD>

dump_netplan_config() {
    echo "Setting WiFi SSID to \"$1\"."
    echo "Setting WIFI password to \"$2\"."
 
    local cfg="50-cloud-init.yaml"
    truncate -s 0 $cfg  
    cat << EOF >> $cfg # I hate YAML :/
network:
  version: 2
  wifis:
    wlan0:
      dhcp4: true
      access-points:
        "$1":
          password: "$2"
  ethernets:
    eth0:
      optional: true
      dhcp4: true
EOF
    chmod 600 $cfg
    cp -f $cfg /etc/netplan
}

main() {
    local ssid="SSID_NETWORK"
    local pass="password"

    while [[ $# -gt 0 ]]; do
        case "$1" in
            -s|--ssid)
                ssid="$2"
                shift 2
                ;;
            -p|--password)
                pass="$2"
                shift 2
                ;;
            *)
                echo "Unknown option: $1"
                exit 1
                ;;
        esac
    done

    dump_netplan_config "$ssid" "$pass"
    netplan apply
}

main "$@"