observability/tp3.md

TP3 : NodeRed

docker run --detach --name nodered ^
  --network tp_net ^
  -p "1880:1880" ^
  -v nodered:/data ^
  -e "TZ=Europe/Paris" ^
  nodered/node-red:4.1

Ajouter la bibliothèque MQTT

#include <curl/curl.h>
#include <string>
#include <iostream>

#include <thread>
#include <atomic>
#include <queue>
#include <mutex>
#include <condition_variable>
#include <csignal>
#include <chrono>
#include <cstring>
#undef timeout
#include "mqtt/async_client.h"

#include <nlohmann/json.hpp>

Dans la fonction ProcessMQTT créer un objet JSON avec les valeurs des différents capteurs.

json obj = {
  {"entree", _digital[IN_FLOW_IN].dvalue},
  {"sortie", _digital[IN_FLOW_OUT].dvalue}
};

Envoyer le message

std::string payload = obj.dump();
auto msg = mqtt::make_message("geii/telemetry", payload);
msg->set_qos(1);
client->publish(msg);