update-godaddy-dns.bash

update-godaddy-dns.bash

#! /usr/bin/env bash
#
# Usage: update-godaddy-dns.sh "api_key" "api_secret" "domain_domain" "domain_name" "log_file"
# Note: log_file defaults to /var/log/update-godaddy-dns.log if not provided

set -e
set -o pipefail

log_file="/var/log/update-godaddy-dns.log"

log_write() {
  local message="$1"
  if [ -n "$message" ]; then
    echo "$(date '+%Y-%m-%d %H:%M:%S'): $message" \
    | tee -a "$log_file" 2> /dev/null
  fi
}

log_fatal() {
  local message="${1}"
  local exit_code=${2:-1}
  log_write "$message"
  exit $exit_code
}

main() {
  local curl="curl -sSf --retry 5 --retry-connrefused --retry-delay 1"
  local api_key="${1:?Missing API key}"
  local api_secret="${2:?Missing API secret}"
  local prefix="${3:?Missing domain prefix}"
  local domain="${4:?Missing domain name}"
  log_file="${5:-$log_file}"
  touch "$log_file" &> /dev/null || log_fatal "Cannot write to $log_file"
  local current_ip="$(
    nslookup "${prefix}.${domain}" \
    | grep '^Address:' \
    | grep -oE '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$'
  )"
  [ $? -ne 0 ] && log_fatal "Error determining the currently set IP address"

  local my_ip="$( $curl "http://ipv4.icanhazip.com/" 2>&1 )"
  [ $? -ne 0 ] && log_fatal "Error querying icanhazip: ${my_ip}"

  if [ "$current_ip" == "$my_ip" ]; then
    log_write "No need to update ${prefix}.${domain}. Current IP: ${current_ip}."
    exit 0
  fi

  # Note: increase the TTL for domains with high traffic. 600 seconds is the lowest godaddy allows.
  local body="$( printf '[ { "data":"%s", "ttl": 600 } ]' ${my_ip:?} )"
  local output=$(
    $curl --header "Authorization: sso-key ${api_key:?}:${api_secret:?}" \
          --header 'Accept:application/json' \
          --header 'Content-Type: application/json' \
          --data "${body:?}" \
          "https://api.godaddy.com/v1/domains/${domain:?}/records/A/${prefix:?}" \
          2>&1
  )
  [ $? -ne 0 ] && log_fatal "Error updating domain in GoDaddy: ${output}"

  log_write "Updated domain ${prefix}.${domain} to ${my_ip}"
  exit 0
}

main $@