====== Download a Remote Config File and Delete it afterwards ======

A very simple Method to roll out configfiles on a bunch of Router: 

The Router will try to download a config file from a ftp server with a unique part in the URL. 
After the File was downloaded successfully it will be deleted on the remote ftp server.

This way you won't have a endless download. 

This Script can be used with various triggers: periodicly every XX min, after wan-up, sdk-startup and so on


<code c remote-config-download.are>
/* DESC: The Router will try to download a config file from a ftp server with a unique part in the URL. 
 * DESC: After the File was downloaded successfully it will be deleted on the remote ftp server
 * Copyright (C) 2017 JJ NetModule AG, Switzerland
 */
 
// ftp/http/ftps/https is possible here
url="ftp://myfileserver.ch/";
user="ftpusername";
pw="ftppassword";

// Get Unique Part of the URL via Serial Number or Hostname
//unique=nb_status("info").SERIAL_NUMBER;
unique=nb_config_get("network.hostname");
// File name on the server
image="cfg.zip";


// local file for storage
local="configfile.zip";


//We will have a remote update Link like: ftp://myfileserver.ch/myhostname/cfg.zip
link=sprintf("%s/%s/%s",url,unique,image);


DELAY=120;
TRIES=5;
for  (i=0;i<TRIES; i++) {
		if (0 == nb_transfer_get(user,pw,link,local)) {
			nb_syslog("Configfile Download successful, %s",link);
			nb_transfer_delete(user,pw,link);
			nb_update_config(sprintf("file:///%s",local));
			exit(0);
		} else {
			nb_syslog("Configfile Download not successfull, retry");
		}

	sleep (DELAY);

}
nb_syslog("Could not download for %d seconds, abort config download",DELAY*TRIES);


</code>