linode_dns.sh

#!/bin/bash
# Update a Linode DNS entry with a network interface's IP address.
# Uses Linode's v3 API.
API_KEY=
DOMAIN_ID=
RESOURCE_ID=
INTERFACE=eth0

get_ip_4() {
    ip addr show $INTERFACE |grep 'inet '|awk '{print $2}'|sed -e "s/\/.*$//"
}

get_ip_6() {
    ip addr show $INTERFACE |grep 'inet6 '|awk '{print $2}'|sed -e "s/\/.*$//"
}

curl "https://api.linode.com/?api_key=$API_KEY&api_action=domain.resource.update&DomainID=$DOMAIN_ID&resourceID=$RESOURCE_ID&target=$(get_ip_4)"