Send Router Status Informations to an MQTT Broker - Advanced Version

/* DESC: Advanced version of mqtt_simple_status.are using a template
 * to easily change topics, publish new messages or create several
 * different connections. 
 * Copyright (C) 2018 NetModule AG, Switzerland
 */
 
template mqtt_status{
 
	/* mqtt variables */
 
	HOST = "";
	PORT = 1883;
	USERNAME = "";
	PASSWORD = "";
	TOPIC=""; 
	MESSAGE="";
 
	QOS = 0; /* 0 = publish at most once (fire & forget) , 1 = publish at least once, 2 = publish exactly once */
	RETAIN = 0; /* 1 = the message will be stored and send to a new subscriber of that topic */	
 
 
	/* Constructor to initialize mqtt settings */
	/* hostname, port, username, password for mqtt broker connection */
	/* also a topic must be set via set_topic() */
 
	void mqtt_status(string h, int p, string u, string up){
		this.HOST = h;
		this.PORT = p;
		this.USERNAME = u;
		this.PASSWORD = up;
		// printf("%s, %i, %s, %s", this.HOST, this.PORT, this.USERNAME, this.PASSWORD);
	}
 
	void set_topic(string t){
		this.TOPIC = t;
	}
	/* Queries nb_status() with provided sections to return the value of desired field */
	string status_query(string section, string status_value){
		stat_info = nb_status(section);
		ret = struct_get(stat_info, sprintf("%s", status_value));
		if(is_void(stat_info) || is_void(ret)){
			return "Couldn't get status";
		}else{
			return ret;
		}
	}
 
	int publish(string msg){
		this.MESSAGE = msg;
		ret = nb_mqtt_publish(this.HOST, this.PORT, this.USERNAME, this.PASSWORD, this.TOPIC, this.QOS, this.RETAIN, this.MESSAGE);
		if(ret<0){
			return -1;
		}else{
			return 0;
		}
	}
}
 
/* The actual script --- simple example as in mqtt_simple_status.are */
 
/* mqtt connection settings for the template */
p = new mqtt_status("192.168.240.1", 1883, "test", "test"); 
 
/* Set a topic to publish to */
p.set_topic("mycompany/bus1/");
 
 
/* Simple loop publishing status messages 10 times with an interval of 60 secs */
for (cnt=0; cnt<10; cnt++){
 
	/* Use status_query() to get desired system infos */
	sys_tmp = p.status_query("system", "TEMPERATURE");
	mob1_service = p.status_query("wwan", "MOBILE1_SERVICE_TYPE");
	mob1_signal = p.status_query("wwan", "MOBILE1_SIGNAL_LEVEL"); 
	gps_long = p.status_query("gnss", "GNSS1_LONGITUDE");
	gps_lat = p.status_query("gnss", "GNSS1_LATITUDE"); 
 
	/* Compose a status message to be published */
	msg = sprintf("Status info: \n temp: %s \n mobile1 service: %s\n mobile 1 signal: %s\n gps long: %s\n gps lat %s\n",sys_tmp, mob1_service, mob1_signal, gps_long, gps_lat);
 
	/* Publis the message */
	stat = p.publish(msg);
 
	if(stat<0){
		nb_syslog("Failed to publish mqtt message");
	}
 
	sleep(60);
 
}
 
/* Change to another topic */
p.set_topic("mycompany/bus1/status/");
 
/* Publish another Message to the new topic */
p.publish("Status update done");
 
exit(0);