autodetect API by length of API key

petrified

@@ -38,9 +38,18 @@ while getopts ":c:" opt; do
 done
 
 ## v2 API - How to update DNS - DDNS_KEY is unique per domain
-DDNS_URL=https://sync.afraid.org/u/
+DDNS_URL=""
 DDNS_KEY=""
 
+## From Josh, v1 key is variable but v2 is fixed length @24char. When set
+## to 0 (auto) the length of the DDNS_KEY will be used to choose which API
+## endpoint, otherwise specify 1 (API v1) or 2 (API v2) directly
+DDNS_API=0
+
+## API URL endpoints, no trailing slashes
+DDNS_V1U=https://freedns.afraid.org/dynamic/update.php
+DDNS_V2U=https://sync.afraid.org/u
+
 ## Which URL to use to get an IP
 # IPv4 icanhazip (http://major.io/icanhazip-com-faq/)
 DDNS_CHECK="http://4.icanhazip.com"
@@ -106,6 +115,28 @@ fi
 if [[ -z "${DDNS_KEY}" ]]; then
   echo "DDNS_KEY must be configured, exiting."
   exit 1
+else
+  # Set the API version endpoint, IP added later
+  case ${DDNS_API} in
+    0)
+      # From Josh, v2 is fixed @24 but v1 is variable (typically >24)
+      if [[ ${#DDNS_KEY} -ne 24 ]]; then
+        DDNS_URL="${DDNS_V1U}?${DDNS_KEY}&address="
+      else
+        DDNS_URL="${DDNS_V2U}/${DDNS_KEY}/?ip="
+      fi
+      ;;
+    1)
+      DDNS_URL="${DDNS_V1U}?${DDNS_KEY}&address="
+      ;;
+    2)
+      DDNS_URL="${DDNS_V2U}/${DDNS_KEY}/?ip="
+      ;;
+    *)
+      echo "DDNS_API must be 0, 1 or 2; exiting."
+      exit 1
+      ;;
+  esac
 fi
 
 # Make sure that PET_LOG will work if required
@@ -219,7 +250,7 @@ fi
 # If they don't match, tell upstream
 __UPDATED=0
 if [[ "${OLDIP}" != "${NEWIP}" ]]; then
-  UPDURL="${DDNS_URL}${DDNS_KEY}/?ip=${NEWIP}"
+  UPDURL="${DDNS_URL}${NEWIP}"
   RESULT=$(curl -m ${CURL_WAIT} -sk "${UPDURL}" 2>/dev/null)
   logmsg "${RESULT}"
   # "Updated foo from 1.2.3.4 to 5.6.7.8"