This gist updates ipv6 and ipv4 address using dyndns for a ionos domain

dyndns_ionos.sh

#!/bin/bash

# === Configuration ===
API_KEY=${1:-"YOUR API KEY"}
INTERFACE=${2:-"eth0"}
IONOS_API_URL="https://ipv4.api.hosting.ionos.com/dns/v1/dyndns"

# === Get global IPv6 address of the interface ===
IPV6_ADDR=$(ip -6 addr show dev "$INTERFACE" scope global | grep -oP '(?<=inet6\s)[0-9a-f:]+(?=/)' | head -n1)
IPV4_ADDR=$(curl -s ipv4.icanhazip.com)

if [ -z "$IPV6_ADDR" ]; then
    echo "No global IPv6 address found on $INTERFACE"
    exit 1
fi

# === Send GET request to IONOS ===
curl -s -X GET "${IONOS_API_URL}?q=${API_KEY}&ipv4=${IPV4_ADDR}&ipv6=${IPV6_ADDR}"

# === Output result ===
if [ $? -eq 0 ]; then
    echo "Successfully sent IPv6 address: $IPV6_ADDR"
else
    echo "Failed to send IPv6 update $IPV6_ADDR"
    exit 1
fi