Add automatic finding of AWS Zone ID for requested domain name

[whereisaaron]

The ACMEScript AWS Route 53 challenge handler should be able to identify the correct Zone ID for each challenge domain name itself. This can be done my checking for the longest suffix of the domain name for which there is a zone listed in Route 53. This would negate the need to specify Zone IDs and would allow certificates for multiple domain names from different zones.

I have an example of this in the dehydrated hook.sh script I wrote. It would be good to port that logic into the main script or Renew-All-Certificates.ps1 .

#
# Remove one level from the front of a domain name
# Returns the rest of the domain name (success), or blank if nothing left (fail)
#
function get_base_name() {
    local HOSTNAME="${1}"

    if [[ "$HOSTNAME" == *"."* ]]; then
      HOSTNAME="${HOSTNAME#*.}"
      echo "$HOSTNAME"
      return 0
    else
      echo ""
      return 1
    fi
}

#
# Find the Route53 zone for this domain name
# Prefers the longest match, e.g. if creating 'a.b.foo.baa.com',
# a 'foo.baa.com' zone will be preferred over a 'baa.com' zone
# Returns the zone name (success) or nothing (fail)
#
function find_zone() {
  local DOMAIN="${1}"

  local ZONELIST=$(cli53 list -format json | jq --raw-output '.[].Name' | sed -e 's/\.$//' | xargs echo -n)

  local TESTDOMAIN="${DOMAIN}"

  while [[ -n "$TESTDOMAIN" ]]; do
    for zone in $ZONELIST; do
      if [[ "$zone" == "$TESTDOMAIN" ]]; then
        echo "$zone"
        return 0
      fi
    done
    TESTDOMAIN=$(get_base_name "$TESTDOMAIN")
  done

  return 1
}