OpenWRT DDNS Porkbun Updater

openwrt_ddns_porkbun_updater.sh

set -e
set -u

__usage="

$0

OpenWRT DDNS updater ('ddns-scripts') script for the Porkbun API.
The script has been extended to support running it directly (eg. via cron) without having to install the \`ddns-scripts\` opkg package.
Suggested script path: /usr/bin/ddns-update-porkbun.sh

Usage (via DDNS updater):
  - Set the DDNS service provider to '-- custom --'
  - Custom update-script: Path to this script
  - Complete 'Lookup Hostname', 'Domain', 'Username' and 'Password' fields.
  
Usage directly #1:
  Export the following envs before running the script:
    \$hostname - Lookup hostname, the FQDN of the ddns record, eg. \`myhost.subdomain.mydomain.com\`
    \$domain   - The root of the porkbun domain, eg. \`mydomain.com\`
    \$username - Porkbun API username ('apikey')
    \$password - Porkbun API secret ('secretapikey')
    \$__IP (optional) - The actual public IP. If not set, will be looked it up form icanhazip.com.
    \$REGISTERED_IP (optional) - The last registered IP. If not set, it will be looked up using nslookup at 1.1.1.1.

Usage directly #2:
  ddns-update-porkbun.sh <domain> <hostname> <username> <password>
  eg:
  ddns-update-porkbun.sh  mydomain.com  myhost.subdomain.mydomain.com  pk1_b7..f8cd  sk1_65..135f
"

if [[ "${1-}" == '-h' || "${1-}" == '--help' ]]; then
  echo "$__usage"
  exit 0
fi

if [[ -z "${__IP-}" ]]; then
  # The script was started outside of the OpenWRT DDNS updater, so we need to exit when there are no IP changes, instead of triggering a forced DNS update.
  manual_script_run='true'
  
  [[ -z "${domain-}" && -n "${1-}" ]] && domain="$1"
  [[ -z "${hostname-}" && -n "${2-}" ]] && hostname="$2"
  [[ -z "${username-}" && -n "${3-}" ]] && username="$3"
  [[ -z "${password-}" && -n "${4-}" ]] && password="$4"
fi

# Mocking write_log to add support for running the script directly.
command -v write_log >/dev/null || alias write_log=echo

write_log 5 'Starting: ddns-update-porkbun.sh'

[[ -z "${domain-}" ]] && { echo "ERROR: \$domain env missing.""$__usage"; exit 1; }
[[ -z "${hostname-}" ]] && { echo "ERROR: \$hostname env missing.""$__usage"; exit 1; }
[[ -z "${apikey-}" ]] && { echo "ERROR: \$apikey env missing.""$__usage"; exit 1; }
[[ -z "${secretapikey-}" ]] && { echo "ERROR: \$secretapikey env missing.""$__usage"; exit 1; }

if [[ -z "${__IP-}" ]]; then
  __IP=$(wget -q https://icanhazip.com -O -)
  write_log 5 "Detected IP: $__IP"
fi

if [[ -z "${REGISTERED_IP-}" ]]; then
  REGISTERED_IP=$(nslookup -type=A "$hostname" 1.1.1.1 | grep -E 'Address: \d+' | cut -d\  -f2)
  write_log 5 "Looked up registered IP: $REGISTERED_IP"
fi

porkbun_record="${hostname%.$domain}"

[[ "$__IP" == "$REGISTERED_IP" && -n "${manual_script_run-}" ]] && { write_log 5 "There are no IP changes, exiting: $__IP == $REGISTERED_IP"; exit 0; }

[[ "$__IP" == "$REGISTERED_IP" ]] && write_log 7 "The IP hasn't changed, DDNS probably triggered a forced update."

# Check if DNS record exists
current_record=$(wget --post-data="{ \"apikey\": \"$username\", \"secretapikey\": \"$password\" }" \
  https://porkbun.com/api/json/v3/dns/retrieveByNameType/$domain/A/${porkbun_record} -O -)
  
echo $current_record | grep -q 'content' || record_missing='true'

if [[ "${record_missing-}" == 'true' ]]; then
  # Create new DNS record
  wget --post-data="{ \"apikey\": \"$username\", \"secretapikey\": \"$password\", \"name\": \"${porkbun_record}\", \"type\": \"A\", \"content\": \"$__IP\", \"ttl\": \"300\" }" \
    "https://porkbun.com/api/json/v3/dns/create/$domain" -O -
  write_log 7 "Created DNS record: $hostname -> $__IP"
else
  # Update existing record
  wget --post-data="{ \"apikey\": \"$username\", \"secretapikey\": \"$password\", \"content\": \"$__IP\", \"ttl\": \"300\" }" \
    "https://porkbun.com/api/json/v3/dns/editByNameType/$domain/A/${porkbun_record}" -O -
  write_log 7 "Updated DNS record: $hostname  $REGISTERED_IP -> $__IP"
fi


write_log 5 'Exiting: ddns-update-porkbun.sh'

uci_show_ddns.conf

ddns.global=ddns
ddns.global.ddns_dateformat='%F %R'
ddns.global.ddns_loglines='250'
ddns.global.ddns_rundir='/var/run/ddns'
ddns.global.ddns_logdir='/var/log/ddns'

ddns.porkbun.lookup_host="$LOOKUP_HOST_FQDN"
ddns.porkbun.domain="$DOMAIN"
ddns.porkbun.username="$APIKEY"
ddns.porkbun.password="$SECRETAPIKEY"

ddns.porkbun=service
ddns.porkbun.use_ipv6='0'
ddns.porkbun.enabled='1'
ddns.porkbun.update_script='/usr/bin/ddns-update-porkbun.sh'
ddns.porkbun.ip_source='network'
ddns.porkbun.ip_network='wan'
ddns.porkbun.interface='wan'
ddns.porkbun.use_syslog='2'
ddns.porkbun.check_unit='minutes'
ddns.porkbun.force_unit='minutes'
ddns.porkbun.retry_unit='seconds'

zzz.md

Update by curl:

curl -X POST "https://porkbun.com/api/json/v3/dns/editByNameType/$domain/A/${porkbun_record}"
-H "Content-Type: application/json"
--data "{ "username": "$username", "secretusername": "$password", "content": "$__IP", "ttl": "300" }"