Example of MQTT Connection

1public async Task Connect_Client()
2{
3  try
4  {
5    var ca = X509Certificate.CreateFromCertFile(@"grouplink-ca.crt");
6    var cert = new X509Certificate2(@"certificate-with-encrypted-key.pfx", "");
7
8    X509Chain ch = new X509Chain();
9    ch.ChainPolicy.ExtraStore.Add(ca);
10
11    Debug.WriteLine("If");
12    Debug.WriteLine(cert.Issuer);
13    Debug.WriteLine(cert.IssuerName);
14    Debug.WriteLine(cert.Subject);
15    Debug.WriteLine(cert.SubjectName);
16
17    var mqttFactory = new MqttFactory();
18
19    var mqttClient = mqttFactory.CreateMqttClient();
20
21    var mqttClientOptions = new MqttClientOptionsBuilder()
22          .WithTcpServer("mqtt.grouplinknetwork.com", 8883)
23          .WithTls(new MqttClientOptionsBuilderTlsParameters()
24          {
25            UseTls = true,
26            SslProtocol = System.Security.Authentication.SslProtocols.Tls12,
27            Certificates = new List<X509Certificate2> { cert },
28            CertificateValidationHandler = delegate { return true; }
29          })
30          .WithCleanSession()
31          .Build();
32
33    mqttClient.ApplicationMessageReceivedAsync += e =>
34    {
35      Debug.WriteLine("Received application message.");
36      Debug.WriteLine(e.ApplicationMessage.ConvertPayloadToString());
37      return Task.CompletedTask;
38    };
39
40    var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
41    var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder()
42      .WithTopicFilter(
43        f =>
44        {
45          f.WithTopic("message/gl-Dataoris");
46        })
47      .Build();
48
49    var res = await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
50    Debug.WriteLine("MQTT client subscribed to topic.");
51  }
52  catch (Exception ex)
53  {
54    Debug.WriteLine("Exception");
55    Debug.WriteLine(ex.Message);
56  }
57
58  finally
59  {
60    Debug.WriteLine("Finally");
61  }
62}

1const mqtt = require("mqtt");
2const fs = require("fs");
3
4const caFile = fs.readFileSync("grouplink-ca.crt");
5const certFile = fs.readFileSync("private.crt");
6const keyFile = fs.readFileSync("private.key");
7
8const options = {
9  protocol: "mqtts",
10  host: "mqtt.grouplinknetwork.com",
11  port: 8883,
12  ca: [caFile],
13  cert: certFile,
14  key: keyFile,
15  rejectUnauthorized: true,
16  clean: false,
17  clientId: "yourOrgName",
18};
19
20const client = mqtt.connect(options);
21const topic = "message/your-org-name";
22console.log("connecting...");
23
24client.on("connect", function () {
25  console.log("connected");
26  client.subscribe(
27    topic,
28    {
29      qos: 1,
30    },
31    function (err) {
32      if (!err) {
33        console.log("subscribed to " + topic);
34      }
35    },
36  );
37});
38
39client.on("disconnect", function () {
40  console.log("disconnected!");
41});
42
43client.on("offline", function () {
44  console.log("offline!");
45});
46
47client.on("error", function (e) {
48  console.log("error: " + JSON.stringify(e));
49  process.exit(1);
50});
51
52client.on("message", function (topic, message) {
53  console.log(message.toString());
54});
55
56