#!/bin/bash

#[ -z "$DDNS_ADMIN_LOGIN" ] && echo "DDNS_ADMIN_LOGIN not set" && exit 1;
[ -z "$DDNS_DOMAINS" ] && echo "DDNS_DOMAINS not set" && exit 1;
[ -z "$DDNS_PARENT_NS" ] && echo "DDNS_PARENT_NS not set" && exit 1;
[ -z "$DDNS_DEFAULT_TTL" ] && echo "DDNS_DEFAULT_TTL not set" && exit 1;

DDNS_IP=$(curl icanhazip.com)

for d in ${DDNS_DOMAINS//,/ }
do
	if ! grep 'zone "'$d'"' /etc/bind/named.conf > /dev/null
	then
		echo "creating zone...";
		cat >> /etc/bind/named.conf <<EOF
zone "$d" {
	type master;
	file "$d.zone";
	allow-query { any; };
	allow-transfer { none; };
	allow-update { localhost; };
};
EOF
	fi

	if [ ! -f /var/cache/bind/$d.zone ]
	then
		echo "creating zone file..."
		cat > /var/cache/bind/$d.zone <<EOF
\$ORIGIN .
\$TTL 86400	; 1 day
$d		IN SOA	${DDNS_PARENT_NS}. root.${d}. (
				74         ; serial
				3600       ; refresh (1 hour)
				900        ; retry (15 minutes)
				604800     ; expire (1 week)
				86400      ; minimum (1 day)
				)
			NS	${DDNS_PARENT_NS}.
			A	${DDNS_IP}
\$ORIGIN ${d}.
\$TTL ${DDNS_DEFAULT_TTL}
EOF
	fi
done

# If /var/cache/bind is a volume, permissions are probably not ok
chown root:bind /var/cache/bind
chown bind:bind /var/cache/bind/*
chmod 770 /var/cache/bind
chmod 644 /var/cache/bind/*