ffmyk influx minimize memory usage

roles/install_monitoring/templates/ffmyk-influx/dhcp.php.j2

@@ -2,9 +2,9 @@
 
 require('func.php');
 
-        $data = file_get_contents('/var/lib/dhcp/dhcpd.leases');
+        $data = shell_exec("grep -e 'lease [[:digit:]\.]\+ {' -e '\s\+ends' /var/lib/dhcp/dhcpd.leases");
 
-        preg_match_all('/lease ([\d\.]+) \{[^\}]+ends \d+ (\d{4}\/\d{2}\/\d{2} \d+:\d{2}:\d{2});[^\}]+}/s', $data, $match);
+        preg_match_all('/lease ([\d\.]+) \{\n\s+ends \d+ (\d{4}\/\d{2}\/\d{2} \d+:\d{2}:\d{2});/s', $data, $match);
 
         unset($data, $match[0]);