codigos-expo-golang-nodered.md

Hello World con Golang (helloworld.go):

package main
import "fmt"

func main() {
    fmt.Printf("hello, world\n")
}

Webservice, API Rest y MongoDB (Mgo) con Golang (test.go):

package main

import (
	"fmt"
	"log"
	"net/http"
	"github.com/gorilla/mux"
	"gopkg.in/mgo.v2"
	"gopkg.in/mgo.v2/bson"
)

// Modelo para manejar los datos con mongodb
type Person struct {
        Id string
        Name string
}

func main() {
	router := mux.NewRouter().StrictSlash(true)
	router.HandleFunc("/addPerson/{name}/{id}", addPerson).Methods("GET")
	router.HandleFunc("/getPerson/{name}", getPerson).Methods("GET")
	log.Fatal(http.ListenAndServe(":8080", router))
}

func addPerson(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	name := vars["name"]
	id := vars["id"]

	// Insercion en mongo
	session, err := mgo.Dial("mongodb://localhost:27017")
	if err != nil {
                panic(err)
        }
	defer session.Close()

	c := session.DB("testgo").C("people")
        err = c.Insert(&Person{id, name})
        if err != nil {
                log.Fatal(err)
        }
}

func getPerson(w http.ResponseWriter, r *http.Request) {

	vars := mux.Vars(r)
	name := vars["name"]

	// Consulta en mongo
	session, err := mgo.Dial("mongodb://localhost:27017")
	if err != nil {
                panic(err)
        }
	defer session.Close()

	c := session.DB("testgo").C("people")
        result := Person{}
        err = c.Find(bson.M{"name": name}).One(&result)
        if err != nil {
                log.Fatal("error: ", err)
        }

        fmt.Println("id:", result.Id, " - name:",result.Name)
}

Código .ino para NodeMCU con Node-Red y MQTT

#include <ESP8266WiFi.h>
#include <PubSubClient.h>

const char *ssid =	"xxxxxxxxxx";		// cannot be longer than 32 characters!
const char *pass =	"yyyyyyyyyy";		//

// Update these with values suitable for your network.
IPAddress server(192, 168, 1, 50);

void callback(const MQTT::Publish& pub) {
  // handle message arrived
  Serial.println("event");
}

WiFiClient wclient;
PubSubClient client(wclient, server);

void setup() {
  // Setup console
  Serial.begin(115200);
  delay(10);
  Serial.println();
  Serial.println();

  client.set_callback(callback);
}

void loop() {
  if (WiFi.status() != WL_CONNECTED) {
    Serial.print("Connecting to ");
    Serial.print(ssid);
    Serial.println("...");
    WiFi.begin(ssid, pass);

    if (WiFi.waitForConnectResult() != WL_CONNECTED)
      return;
    Serial.println("WiFi connected");
  }

  if (WiFi.status() == WL_CONNECTED) {
    if (!client.connected()) {
      if (client.connect("nodeMCUClient")) {
	client.publish("ourtopic","hello world");
	client.subscribe("thetopic");
      }
    }

    if (client.connected())
      client.loop();
  }
}