Dynamic DNS records for Freifunk nodes from meshviewer.json

ffmuc-nodes-ddns.sh

#!/bin/bash

set -ex

# prefix of node hostnames to filter for
PREFIX=""

# TSIG key name
KEYNAME=""
# base64 encoded TSIG key
KEY=""
# base domain / zone where records should be added
BASEDOMAIN=""
# address of authoritative DNS server for the above specified zone
DNSSERVER=""

NODES=$(curl -sSL https://map.ffmuc.net/data/meshviewer.json | jq '[.nodes[] | select(.hostname | startswith("$PREFIX")) | pick(.hostname, .node_id, .addresses)]')


cmd="
server $DNSSERVER 53
zone $BASEDOMAIN
"

#echo "$NODES" | jq -c '.[]' | while read -r node
while read -r node
do
        hostname=$(echo "$node" | jq -r '.hostname')
        id=$(echo "$node" | jq -r '.node_id')
        ip0=$(echo "$node" | jq -r '.addresses[0]')
        ip1=$(echo "$node" | jq -r '.addresses[1]')
        cmd+="update delete $hostname.$BASEDOMAIN. AAAA"$'\n'
        cmd+="update delete $id.$BASEDOMAIN. AAAA"$'\n'
        cmd+="update add $hostname.$BASEDOMAIN. 300 AAAA $ip0"$'\n' 
        cmd+="update add $hostname.$BASEDOMAIN. 300 AAAA $ip1"$'\n' 
        cmd+="update add $id.$BASEDOMAIN. 300 AAAA $ip0"$'\n'
        cmd+="update add $id.$BASEDOMAIN. 300 AAAA $ip1"$'\n'
done < <(echo "$NODES" | jq -c '.[]')

cmd+="key hmac-sha512:$KEYNAME $KEY"$'\nsend\n'

echo "$cmd" | nsupdate