Update DNS A record with Gandi's API

gandi.sh

#!/bin/sh

# Customize with your data - see: https://api.gandi.net/docs/authentication/
read 2>/dev/null -r APIKEY <APIKEY.txt || APIKEY='...'
read 2>/dev/null -r DOMAIN <DOMAIN.txt || DOMAIN='...'
read 2>/dev/null -r RECORD <RECORD.txt || RECORD='...'

### DO NOT EDIT AFTER THIS LINE
API="https://api.gandi.net/v5/livedns/domains/$DOMAIN"

command -v 'curl' >/dev/null || { echo "[ERROR] - missing 'curl'"; exit 2; }
command -v 'dig'  >/dev/null || { echo "[ERROR] - missing 'dig'" ; exit 2; }
command -v 'jq'   >/dev/null || { echo "[ERROR] - missing 'jq'"  ; exit 2; }

CURRENT_IP="$( curl -4 --silent ifconfig.co/ip )" || exit 1
IPLENGTH="${#CURRENT_IP}"

# check that ifconfig.co give's an IP-address:
test "${IPLENGTH}" -gt 30 || exit 3

NAMESERVER="$( curl --silent --header "Authorization: Apikey ${APIKEY}" "$API/nameservers" | jq  --raw-output '.[0] | sub("^.*?_"; "")' )"
LAST_REGISTERED_IP="$( dig +short "$RECORD.$DOMAIN" "@$NAMESERVER" )"

# only update if needed:
[ "$CURRENT_IP" != "$LAST_REGISTERED_IP" ] && \
  curl --silent -X PUT --header "Authorization: Apikey $APIKEY" \
              --header "Content-Type: application/json" \
              --data "{\"rrset_values\": [\"$CURRENT_IP\"], \"rrset_ttl\": 300}" \
              "$API/records/$RECORD/A"