Azure IoT v2

This library is a built-in class that provides functions to communicate with Azure IoT Hub.

Library usage requirements
Type	Integrations
Name	Azure_IoT_V2
Version	2.1.0
Code size used	4.1KB
Resources used	HTTPS x 1, MQTT x 1, Timers x 1

Limitations

This library only supports device authentication with Shared Access Signature (SAS) tokens.
Device authentication using the x.509 certificate is not supported.

Abstracts

Methods()/Properties	Summary	Note
new AZURE_IOT()	Creates an AZURE_IOT instance.

{AZURE_IOT} Instance

Methods()/Properties	Summary	Note
.generateSasToken()	Generates a SAS token.
.httpPost()	Sends data to Azure IoT Hub via HTTPS.
.abortHttpRequest()	Aborts the currently ongoing HTTP request.
.mqttConnect()	Connects to Azure IoT Hub with MQTT.
.errors	Array containing invalid key names (string) Generated when an invalid parameter is detected in the constructor or .setConfig().
.CONST.VERSION	Version (string)	v2.1.0+

Details

new AZURE_IOT([config])

Creates an AZURE_IOT instance.

Name	Type	M/O	Description	Note
config	Object	optional	Configuration Refer to config for details.
return	{AZURE_IOT}	-	{AZURE_IOT} : Generated {AZURE_IOT}	If invalid parameters are detected, .errors will be generated.

config

Name	Type	M/O	Description	Note
host	string	mandatory	An Azure IoT Hub endpoint By default, the DNS name of Azure IoT Hub looks like `{IoT Hub name}.azure-devices.net`.
deviceId	string	mandatory	Device ID This is created when a device is registered to the identity registry in Azure IoT Hub.
primaryKey	string	mandatory	Service Primary Key Specify a symmetric device key or a shared access key in the identity registry.
ca	string	mandatory	Root CA certificate for Azure IoT Hub Specify a string in PEM format. Use `\n` for line feed code.
tokenTimeout	number	optional	SAS token timeout value [s] Specify the period during which the generated SAS tokens will be valid. The default value is `3600`.
httpTimeout	number	optional	HTTP request timeout value [s] If `0`, the timeout function is disabled. The default value is `0`.	v2.1.0+
timeout	number	-	This parameter is ignored.	Unused

Set the Configuration (config) when creating an AZURE_IOT instance.
If an invalid parameter is detected, an array containing the name of the invalid keys is generated as the .errors property. If the parameters are successful, the .errors property will be deleted.

var iot = new AZURE_IOT({
    host: <value>,
    deviceId: <value>,
    primaryKey: <value>,
    ca: <value>,
    tokenTimeout: <value>
});
if('errors' in iot) {
    //TODO: Handle errors
}

.setConfig(config)

Set the Configuration (config) after the AZURE_IOT instance is created.
If an invalid parameter is detected, an array containing the name of the invalid keys is generated as the .errors property. If the parameters are successful, the .errors property will be deleted.

var iot = new AZURE_IOT();
iot.setConfig({
    host: <value>,
    deviceId: <value>,
    primaryKey: <value>,
    ca: <value>,
    tokenTimeout: <value>
});
if('errors' in iot) {
    //TODO: Handle errors
}

Setter Methods

After the AZURE_IOT instance is created, Configuration (config) can be set individually using the following setter methods.
If successful, the own instance is returned. If an invalid parameter is detected, false is returned.

Setter Method	Description	Note
.setHost(value)	Sets the `host`.
.setDeviceId(value)	Sets the `deviceId`.
.setPrimaryKey(value)	Sets the `primaryKey`.
.setRootCA(value)	Sets the `ca`.
.setTokenTimeout(value)	Sets the `tokenTimeout`.
.setHttpTimeout(value)	Sets the `httpTimeout`.	v2.1.0+
.setTimeout(value)	Sets the `timeout`.	Unused

.generateSasToken([[[[resourceUri],signingKey],policyName],expiresInSecs])

Generates a SAS token.

Name	Type	M/O	Description
resourceUri	string	optional	Specify the URI prefix of the endpoint. The default value is `${config.host}/devices/${config.deviceId}`.
signingKey	string	optional	Specify the signature key for the SAS token. The default value is `config.primaryKey`.
policyName	string	optional	Specify the shared access policy name. Only if specified, the authorization rule name is added to the SAS token. The default value is `undefined`.
expiresInSecs	number	optional	Specify the token timeout value [s]. The expiration time of the token is the time this method is called, added to this timeout value. The default value is `config.tokenTimeout`.
return	string	-	Authentication token used to establish HTTPS requests or MQTT connections

.httpPost(token,length,getBody,callback[[,endpoint],sockTo])

Sends data to Azure IoT Hub via HTTPS.

Name	Type	M/O	Description	Note
token	string	mandatory	Specify the authentication token generated by the .generateSasToken() method.
length	number	mandatory	Specify the size of the data (`body`) to be sent.
getBody	function	mandatory	Execute callback processing at the timing when this method will accept the data (`body`) to be sent. Returns data in `string` or `ArrayBuffer` chunks of 4KB or less until there is no more data, and finally returns `null`.
callback(err, resp)	function	mandatory	Execute callback processing when this method is completed. Notify the processing result using the argument of the callback function. err: {HttpReqError}, null resp: {HttpResponse}, null If an error occurs in the HTTP request, `err` is set; if an HTTP response could be received, `resp` is set.
endpoint	string	optional	Specify the routing endpoint. The default value is `/devices/${config.deviceId}/messages/events?api-version=2018-06-30`.
sockTo	number	optional	Specify the HTTP session timeout value [ms]. This parameter is the `sockTo` setting value of the `https.request()` method. For details, refer to the HTTPS object specification.	v2.1.0+
return	undefined	-

{HttpReqError}

Name	Type	Description	Note
.errCode	number	The error code of the HTTPS request For details, refer to the error code table of the HTTPS object.

{HttpResponse}

Name	Type	Description
.statusCode	number	The status code of the HTTP response
.statusMessage	string	The status message of the HTTP response
.body	string, null	HTTP response data (`Response-Body`)

.abortHttpRequest()

Aborts the currently ongoing HTTP request.

Name	Type	M/O	Description	Note
return	undefined	-

.mqttConnect(token[,options])

Connects to Azure IoT Hub with MQTT.

This method is a wrapper function for the mqtt.connect() method.
Create an MQTT client instance {Client} for MQTT connection to Azure IoT Hub.
Refer to MQTT object specification for information on how to use the generated {Client} instance.

Name	Type	M/O	Description
token	string	mandatory	Specify the authentication token generated by the .generateSasToken() method.
options	object	optional	This parameter is the `options` setting of the `mqtt.connect()` method. For details, refer to the MQTT object specification. Note that some parameters are overridden by this method.
return	{Client}, undefined	-	MQTT client instance for Azure IoT Hub

Configuration values related to `mqtt.connect()` that are overridden by this method:

mqtt.set(’ssl.ca’, certificate)
- certificate: config.ca
mqtt.connect(url[, options])
- url: mqtts://${config.host}:8883
- options.clientId: config.deviceId
- options.username: ${config.host}/${config.deviceId}/?api-version=2018-06-30
- options.password: token

Usage Examples

The following common code is used in all sample code:

Make sure that the root CA certificate is appropriate for the Azure IoT Hub endpoint in advance.
For information on how to obtain a CA certificate, please refer to here.

log.setLevel(0,2); //-1:NONE 0:ERROR 1:WARNING 2:DEBUG 3:TRACE, 0:DISABLE 1:LOG 2:CONSOLE 3:BOTH
log.printLevel(2); //0:DISABLE 1:LOG 2:CONSOLE 3:BOTH

var rootCa = '-----BEGIN CERTIFICATE-----\n...<CA>...\n-----END CERTIFICATE-----';

//TODO: Configuration
var config = {
    host: <value>,
    deviceId: <value>,
    primaryKey: <value>,
    ca: rootCa,
    tokenTimeout: <value>
};
var iot = new AZURE_IOT(config);
if('errors' in iot) {
    //TODO: Handle errors
    throw new Error("Invalid configuration");
}

Sample 1

Send data to Azure IoT Hub via HTTPS.

var token = iot.generateSasToken();
var body = "sample text to send to Azure IoT Hub";

var busy;
var getBody = function() {
    var temp = body;
    body = null;
    return temp;
};
var callback = function(err, resp) {
    if(err) {
        print("Error!", err.errCode);
    } else {
        print("Response:", resp.body);
        print("Status:", resp.statusCode, resp.statusMessage);
    }
    busy = false;
};

busy = true;
iot.httpPost(token, body.length, getBody, callback);
while(busy);
print("Done");

Sample 2

Send data in chunks to Azure IoT Hub via HTTPS.

var token = iot.generateSasToken();
var body = "sample text to send to Azure IoT Hub[...]";

var busy;
var chunkSize = 8; //4KB or less
var index = 0;
var getBody = function() {
    var chunk = body.substring(index, index + chunkSize);
    if(chunk) {
        index = index + chunkSize;
        return chunk;
    }
    return null;
};
var callback = function(err, resp) {
    if(err) {
        print("Error!", err.errCode);
    } else {
        print("Response:", resp.body);
        print("Status:", resp.statusCode, resp.statusMessage);
    }
    busy = false;
};

busy = true;
iot.httpPost(token, body.length, getBody, callback);
while(busy);
print("Done");

Sample 3

Connect to Azure IoT Hub with MQTT.
When the MQTT connection is disconnected, update the token and reconnect MQTT.

var mqttConnect = function(onConnected, onDisconnected) {
    var token = iot.generateSasToken(); //Update token
    print(token);
    var cli = iot.mqttConnect(token);
    if(!cli) return undefined;
    cli.on('error', function(err) {
        //TODO: Handle errors
        print("Error!", err.code, `(${cli.get('errnoConnect')})`);
        if(err.code == 1 && onDisconnected) { //Connection failed
            onDisconnected();
            return;
        }
    });
    cli.on('message', function(topic, message) {
        //TODO: Handle messages
        print("Message:", `[${topic}]`, message);
    });
    cli.on('close', function() {
        print("DISCONNECTED");
        if(onDisconnected) {
            onDisconnected();
        }
    });
    cli.on('connect', function() {
        print("CONNECTED");
        if(onConnected) {
            onConnected();
        }
    });
    return cli;
};

var onMqttConnect = function() {
    client.subscribe(`devices/${config.deviceId}/messages/devicebound/#`, { qos: 1 }, function(err) {
        if(err.code != 0) {
            //TODO: Handle errors
            print("Subscribe failed:", err.code);
        }
    });
};
var onMqttDisconnect = function() {
    if(client) client.end();
    client = undefined;
    setTimeout(function() {
        print("Reconnecting...");
        client = mqttConnect(onMqttConnect, onMqttDisconnect);
        if(!client) {
            onMqttDisconnect();
        }
    }, 10000);
};

var client = mqttConnect(onMqttConnect, onMqttDisconnect);
if(!client) {
    throw new Error("Failed to create mqtt instance");
}

var publishInterval = 5 * 1000;
var publishEvent = false;
var publishCnt = 0;
setInterval(function() {
    publishEvent = true;
}, publishInterval);

while(1) {
    if(client && client.canPublish() && publishEvent) {
        publishEvent = false;
        publishCnt++;
        var message = JSON.stringify({ "message": "publish" + publishCnt });
        client.publish(`devices/${config.deviceId}/messages/events/?api-version=2018-06-30`, message, { qos: 1 }, function(err) {
            if(err.code == 0) {
                print("Publish OK");
            } else {
                //TODO: Handle errors
                print("Publish failed:", err.code);
            }
        });
    }
}

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Updated: 2024-03-26

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Related Documents

Limitations

Abstracts

{AZURE_IOT} Instance

Details

new AZURE_IOT([config])

config

.setConfig(config)

Setter Methods

.generateSasToken([[[[resourceUri],signingKey],policyName],expiresInSecs])

.httpPost(token,length,getBody,callback[[,endpoint],sockTo])

{HttpReqError}

{HttpResponse}

.abortHttpRequest()

.mqttConnect(token[,options])

Configuration values related to `mqtt.connect()` that are overridden by this method:

Usage Examples

Sample 1

Sample 2

Sample 3

Related Documents

Limitations

Abstracts

{AZURE_IOT} Instance

Details

new AZURE_IOT([config])

config

.setConfig(config)

Setter Methods

.generateSasToken([[[[resourceUri],signingKey],policyName],expiresInSecs])

.httpPost(token,length,getBody,callback[[,endpoint],sockTo])

{HttpReqError}

{HttpResponse}

.abortHttpRequest()

.mqttConnect(token[,options])

Configuration values related to mqtt.connect() that are overridden by this method:

Usage Examples

Sample 1

Sample 2

Sample 3

Configuration values related to `mqtt.connect()` that are overridden by this method: