Polish KarlDNS production UI and docs

scripts/karldns-update.sh

@@ -8,7 +8,7 @@ if [ -r "$CONFIG_FILE" ]; then
   . "$CONFIG_FILE"
 fi
 
-: "${KARLDNS_UPDATE_URL:?KARLDNS_UPDATE_URL is required in $CONFIG_FILE or the environment}"
+: "${KARLDNS_UPDATE_URL:?Set KARLDNS_UPDATE_URL in $CONFIG_FILE or the environment}"
 KARLDNS_BASE_URL="${KARLDNS_BASE_URL:-https://karldns.de}"
 KARLDNS_LOCK_FILE="${KARLDNS_LOCK_FILE:-/tmp/karldns-updater.lock}"
 KARLDNS_CACHE_FILE="${KARLDNS_CACHE_FILE:-${XDG_CACHE_HOME:-$HOME/.cache}/karldns/last-ip}"
@@ -49,8 +49,8 @@ elif [ "$KARLDNS_IPV6" != "off" ]; then
   ipv6="$KARLDNS_IPV6"
 fi
 
-case "$ipv4" in *" "*) echo "KarlDNS: invalid IPv4 discovery result" >&2; exit 1 ;; esac
-case "$ipv6" in *" "*) echo "KarlDNS: invalid IPv6 discovery result" >&2; exit 1 ;; esac
+case "$ipv4" in *" "*) echo "KarlDNS: could not read a valid IPv4 address" >&2; exit 1 ;; esac
+case "$ipv6" in *" "*) echo "KarlDNS: could not read a valid IPv6 address" >&2; exit 1 ;; esac
 public_ip="${ipv4}|${ipv6}"
 has_discovered_ip=0
 if [ -n "$ipv4" ] || [ -n "$ipv6" ]; then
@@ -87,7 +87,7 @@ case "$response" in
     echo "KarlDNS: $response"
     ;;
   *)
-    echo "KarlDNS: update failed: $response" >&2
+    echo "KarlDNS: update failed. Server said: $response" >&2
     exit 1
     ;;
 esac