bin/scripts/update_home_dns.sh
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#!/bin/bash
#
# This is a script to update a Netlify subdomain A record with the current external IP.
# The example below would update the local.example.com A record to the current external IP with a TTL of 5 minutes.
#
# Usage:
# netlify-ddns.sh <ACCESS_TOKEN> <DOMAIN> <SUBDOMAIN> <TTL>
#
# Example:
# netlify-ddns.sh aCcEsStOKeN example.com local 300
#
# if [ "$#" -ne 4 ]; then
# echo "Wrong number of parameters passed"
# echo "Usage:"
# echo "$0 <ACCESS_TOKEN> <DOMAIN> <SUBDOMAIN> <TTL>"
# exit
# fi
# ACCESS_TOKEN="$1"
# DOMAIN="$2"
# SUBDOMAIN="$3"
# TTL="$4"
ACCESS_TOKEN="$NETLIFY_ACCESS_TOKEN"
DOMAIN="prithu.xyz"
SUBDOMAIN="$SUBDOMAIN_"
TTL="300"
NETLIFY_API="https://api.netlify.com/api/v1"
EXTERNAL_IP=`dig +short myip.opendns.com @resolver1.opendns.com`
echo "Current external IP is $EXTERNAL_IP"
HOSTNAME="$SUBDOMAIN.$DOMAIN"
DNS_ZONES_RESPONSE=`curl -s "$NETLIFY_API/dns_zones?access_token=$ACCESS_TOKEN" --header "Content-Type:application/json"`
ZONE_ID=`echo $DNS_ZONES_RESPONSE | jq ".[] | select(.name == \"$DOMAIN\") | .id" --raw-output`
DNS_RECORDS_RESPONSE=`curl -s "$NETLIFY_API/dns_zones/$ZONE_ID/dns_records?access_token=$ACCESS_TOKEN" --header "Content-Type:application/json"`
RECORD=`echo $DNS_RECORDS_RESPONSE | jq ".[] | select(.hostname == \"$HOSTNAME\")" --raw-output`
RECORD_VALUE=`echo $RECORD | jq ".value" --raw-output`
echo "Current $HOSTNAME value is $RECORD_VALUE"
if [[ "$RECORD_VALUE" != "$EXTERNAL_IP" ]]; then
if [[ "$RECORD_VALUE" != "" ]]; then
echo "Deleting current entry for $HOSTNAME"
RECORD_ID=`echo $RECORD | jq ".id" --raw-output`
DELETE_RESPONSE_CODE=`curl -X DELETE -s -w "%{response_code}" "$NETLIFY_API/dns_zones/$ZONE_ID/dns_records/$RECORD_ID?access_token=$ACCESS_TOKEN" --header "Content-Type:application/json"`
if [[ $DELETE_RESPONSE_CODE != 204 ]]; then
echo "There was a problem deleting the existing $HOSTNAME entry, response code was $DELETE_RESPONSE_CODE"
exit
fi
fi
echo "Creating new entry for $HOSTNAME with value $EXTERNAL_IP"
CREATE_BODY=`jq -n --arg hostname "$HOSTNAME" --arg externalIp "$EXTERNAL_IP" --arg ttl $TTL '
{
"type": "A",
"hostname": $hostname,
"value": $externalIp,
"ttl": $ttl|tonumber
}'`
CREATE_RESPONSE=`curl -s --data "$CREATE_BODY" "$NETLIFY_API/dns_zones/$ZONE_ID/dns_records?access_token=$ACCESS_TOKEN" --header "Content-Type:application/json"`
NEW_RECORD_TYPE=`echo $CREATE_RESPONSE | jq ".type" --raw-output`
NEW_RECORD_HOSTNAME=`echo $CREATE_RESPONSE | jq ".hostname" --raw-output`
NEW_RECORD_VALUE=`echo $CREATE_RESPONSE | jq ".value" --raw-output`
NEW_RECORD_TTL=`echo $CREATE_RESPONSE | jq ".ttl" --raw-output`
if [[ $NEW_RECORD_TYPE != "A" ]] || [[ $NEW_RECORD_HOSTNAME != $HOSTNAME ]] || [[ $NEW_RECORD_VALUE != $EXTERNAL_IP ]] || [[ $NEW_RECORD_TTL != $TTL ]]; then
echo "There was a problem creating the new entry, some values did not match"
exit
fi
fi