Connect Master API Tutorial

Run the example

  1. Install and run the master gateway. Create the needed certificates as described in the Certificate Management.
  2. Install and run the device gateway. Configure the device gateway to connect to the master gateway as described in the Configuration.
  3. Download the Node.js client library
  4. Copy the certificates.
    • Copy the root certificate of the master gateway to your working directory. As default, the certificate(ca.crt) resides in cert of the installation directory of the master gateway.
    • Copy the administrator certificate and its private key to your working directory.
    • Copy the tenant certificate and its private key to your working directory.
  5. Change the server information in example/connectMaster/test/test.js as needed.

     // the path of the root certificate
     const MASTER_CA_FILE = '../../../../cert/master/ca.crt'; 
    
     // the address of the master gateway
     const MASTER_IP = '192.168.0.2';
     const MASTER_PORT = 4010;
    
     // the paths of the administrator certificate and its key 
     const ADMIN_CERT_FILE = '../../../../cert/master/admin.crt';
     const ADMIN_KEY_FILE = '../../../../cert/master/admin_key.pem';
    
     // the paths of the tenant certificate and its key    
     const TENANT_CERT_FILE = '../../../../cert/master/tenant1.crt';
     const TENANT_KEY_FILE = '../../../../cert/master/tenant1_key.pem';    
    
     // the following values should be same as the IDs in the corresponding certificates
     const TENANT_ID = "tenant1";
     const GATEWAY_ID = "gateway1";   
    
  6. Install packages.

     npm install
    
  7. Run.

     cd example/connectMaster/test
     node test.js
    

    To initialize the database, you have to run with -i option once.

1. CLI

With the Command-Line Interface(CLI), you can test 5 functions related to connection management.

$ node test.js

===== Main Menu =====

(1) Search devices
(2) Connect to a device synchronously
(3) Manage asynchronous connections
(4) Accept devices
(5) Device menu
(q) Quit

>>>>> Select a menu:

(1) Search devices

To connect devices, you have to know their addresses and related options such as connection mode. By using ConnectMaster.SearchDevice, you can get these information in a subnet.

>>>>> Select a menu: 1
Searching devices in the subnet...
***** Found devices: 9
[ { deviceid: 540092578,
    type: 12,
    usedhcp: true,
    connectionmode: 0,
    ipaddr: '192.168.0.120',
    port: 51211,
    usessl: true },
  { deviceid: 544114231,
    type: 13,
    usedhcp: true,
    connectionmode: 0,
    ipaddr: '192.168.0.104',
    port: 51211,
    usessl: false },
  { deviceid: 846,
    type: 18,
    usedhcp: true,
    connectionmode: 0,
    ipaddr: '192.168.0.117',
    port: 51211,
    usessl: false },

(2) Connect to a device synchronously

The simplest way of connecting to a device is to use ConnectMaster.Connect.

>>>>> Select a menu: 2
Connect to a device synchronously...
>> Enter the IP address of the device: 192.168.0.104
>> Enter the port of the device (default: 51211):
>> Use SSL y/n (default: n):
Trying to connect to 192.168.0.104:51211...
Connected to 544114231

[TCP Connected]:  { deviceid: 544114231, status: 1, timestamp: 1584826654 }

(3) Manage asynchronous connections

When you have to manage permanent connections to multiple devices, asynchronous APIs would be a better choice. With these APIs, the gateway will handle connections to devices in the background. For example, if some devices are disconnected, the gateway will try to reconnect them automatically.

>>>>> Select a menu: 3

***** Async connections: 0
[]

===== Async Menu =====

(1) Add async connections
(2) Delete async connections
(3) Refresh the connection list
(q) Return to Main Menu

>>>>> Select a menu: 1
>> Enter the device ID (Press just ENTER if no more device): 540092578
>> Enter the IP address of the device: 192.168.0.120
>> Enter the port of the device (default: 51211):
>> Use SSL y/n (default: n): y
>> Enter the device ID (Press just ENTER if no more device): 939504224
>> Enter the IP address of the device: 192.168.0.110
>> Enter the port of the device (default: 51211):
>> Use SSL y/n (default: n):
>> Enter the device ID (Press just ENTER if no more device):
Adding asynchronous connections for 2 devices...

***** Async connections: 2
[ { deviceid: 540092578,
    connectionmode: 0,
    ipaddr: '192.168.0.120',
    port: 51211,
    status: 0,
    autoreconnect: true,
    usessl: true },
  { deviceid: 939504224,
    connectionmode: 0,
    ipaddr: '192.168.0.110',
    port: 51211,
    status: 0,
    autoreconnect: true,
    usessl: false } ]

[TCP Connected]:  { deviceid: 939504224, status: 1, timestamp: 1584826789 }

[TLS Connected]:  { deviceid: 540092578, status: 2, timestamp: 1584826791 }

(4) Accept devices

In some environments, the devices should connect to the gateway, not vice versa. For devices to connect to the gateway, you have to do the followings;

  1. Change the connection mode to DEVICE_TO_SERVER using ConnectMaster.SetConnectionMode.
  2. By default, the gateway will not accept any incoming connections. You have to add the devices to the accept filter using ConnectMaster.SetAcceptFilter.
>>>>> Select a menu: 4

***** Pending devices: 1
[ { deviceid: 939342898,
    ipaddr: '192.168.0.121',
    lasttry: 1584826860 } ]

***** Accept filter:  { allowall: false,
  deviceidsList: [],
  ipaddrsList: [],
  subnetmasksList: [] }

===== Accept Menu =====

(1) Add devices to the filter
(2) Delete devices from the filter
(3) Allow all devices
(4) Disallow all devices
(5) Refresh the pending device list
(q) Return to Main Menu

>>>>> Select a menu: 3

***** Accept filter:  { allowall: true,
  deviceidsList: [],
  ipaddrsList: [],
  subnetmasksList: [] }

[TLS Connected]:  { deviceid: 939342898, status: 2, timestamp: 1584826884 }

Apart from the IP address, there are two important options for device connections. You can change the connection mode using ConnectMaster.SetConnectionMode and enable/disable SSL using the SSL APIs.

>>>>> Select a menu: 5

***** Managed devices: 4
[ { deviceid: 939504224,
    connectionmode: 0,
    ipaddr: '192.168.0.110',
    port: 51211,
    status: 1,
    autoreconnect: true,
    usessl: false },
  { deviceid: 939342898,
    connectionmode: 1,
    ipaddr: '192.168.0.121',
    port: 0,
    status: 2,
    autoreconnect: false,
    usessl: true },
  { deviceid: 544114231,
    connectionmode: 0,
    ipaddr: '192.168.0.104',
    port: 51211,
    status: 1,
    autoreconnect: false,
    usessl: false },
  { deviceid: 540092578,
    connectionmode: 0,
    ipaddr: '192.168.0.120',
    port: 51211,
    status: 2,
    autoreconnect: true,
    usessl: true } ]

===== Device Menu =====

(1) Set connection mode
(2) Enable SSL
(3) Disable SSL
(4) Disconnect
(5) Disconnect All
(6) Refresh the device list
(q) Return to Main Menu

>>>>> Select a menu: 2

Enter the device IDs to enable SSL
Enter the device ID (Press just ENTER if no more device): 544142231
Enter the device ID (Press just ENTER if no more device):

To change these options, you have to connect to the devices first using menu (2) ~ (4).

2. Synchronous connections

You can use the Synchronous APIs to manage the connections by yourself.

function connectToDevice(gatewayID, addr, port, useSSL) {
  var connInfo = new connectMessage.ConnectInfo();
  connInfo.setIpaddr(addr);
  connInfo.setPort(port);
  connInfo.setUsessl(useSSL);

  var req = new connectMasterMessage.ConnectRequest();
  req.setGatewayid(gatewayID);
  req.setConnectinfo(connInfo);

  return new Promise((resolve, reject) => {
    connectMaster.getClient().connect(req, (err, response) => {
      resolve(response.getDeviceid());
    });
  });
}

function disconnect(deviceIDs) {
  var req = new connectMasterMessage.DisconnectRequest();
  req.setDeviceidsList(deviceIDs);

  return new Promise((resolve, reject) => {
    connectMaster.getClient().disconnect(req, (err, response) => {
      resolve(response);
    });
  });
}
var devID = await connectMaster.connectToDevice(gatewayID, connInfo.getIpaddr(), connInfo.getPort(), connInfo.getUsessl());

// do something with the devID

await connectMaster.disconnect(deviceIDs);

3. Asynchronous connections

With the Asynchronous APIs, you only have to register or deregister devices. The gateway will handle all the connection related tasks in the background.

function addAsyncConnection(gatewayID, connInfos) {
  var req = new connectMasterMessage.AddAsyncConnectionRequest();
  req.setGatewayid(gatewayID);
  req.setConnectinfosList(connInfos);

  return new Promise((resolve, reject) => {
    connectMaster.getClient().addAsyncConnection(req, (err, response) => {
      resolve(response);
    });
  });
}

function deleteAsyncConnection(gatewayID, deviceIDs) {
  var req = new connectMasterMessage.DeleteAsyncConnectionRequest();
  req.setGatewayid(gatewayID);
  req.setDeviceidsList(deviceIDs);

  return new Promise((resolve, reject) => {
    connectMaster.getClient().deleteAsyncConnection(req, (err, response) => {
      resolve(response);
    });
  });
}

You have to use ConnectMaster.GetDeviceList to get the status of the registered devices.

async function showAsyncConnection() {
  var connInfos = [];

  try {
    var devList = await connectMaster.getDeviceList(mainMenu.getGatewayID());

    for(let i = 0; i < devList.length; i++) {
      if(devList[i].autoreconnect) {
        connInfos.push(devList[i]);
      }
    }

    console.log(`\n***** Async connections: ${connInfos.length}`);
    console.log(connInfos);

    return connInfos;
  }  catch (err) {
    console.error('Cannot get the async connections: ', err);
    return null;
  }
}

4. Accept devices

function getAcceptFilter(gatewayID) {
  var req = new connectMasterMessage.GetAcceptFilterRequest();
  req.setGatewayid(gatewayID);

  return new Promise((resolve, reject) => {
    connectMaster.getClient().getAcceptFilter(req, (err, response) => {
      resolve(response.toObject().filter);
    })
  })
}

function setAcceptFilter(gatewayID, filter) {
  var req = new connectMasterMessage.SetAcceptFilterRequest();
  req.setGatewayid(gatewayID);
  req.setFilter(filter);

  return new Promise((resolve, reject) => {
    connectMaster.getClient().setAcceptFilter(req, (err, response) => {
      resolve(response);
    })
  })
}

By default, the gateway will not accept any incoming connections. ConnectMaster.GetPendingList can be used to get the devices, which are trying to connect to the gateway but not in the accept filter.

function getPendingList(gatewayID) {
  var req = new connectMasterMessage.GetPendingListRequest();
  req.setGatewayid(gatewayID);

  return new Promise((resolve, reject) => {
    connectMaster.getClient().getPendingList(req, (err, response) => {
      resolve(response.toObject().deviceinfosList);
    });
  });
}

You can allow all the incoming connections by setting AcceptFilter.allowAll to true. Or, you can specify the devices to be allowed in AcceptFilter.deviceIDs.

async function allowAll() {
  try {
    var filter = new connect.connectMessage.AcceptFilter();
    filter.setAllowall(true);
    filter.setDeviceidsList([]);

    await connectMaster.setAcceptFilter(mainMenu.getGatewayID(), filter);
    await showAcceptFilter();
  } catch (err) {
    console.error('Cannot allow all devices: ', err);
  }
}

async function addDevicesToFilter() {
  var deviceIDs = menu.getDeviceIDs();

  if(deviceIDs.length == 0) {
    console.error('No device to add');
    return;
  }

  try {
    var oldFilter = await connectMaster.getAcceptFilter(mainMenu.getGatewayID());

    var newFilter = new connect.connectMessage.AcceptFilter();
    newFilter.setAllowall(false);
    
    var newDeviceIDs = oldFilter.deviceidsList;

    for(let i = 0; i < deviceIDs.length; i++) {
      let exist = false;

      for(let j = 0; j < newDeviceIDs.length; j++) {
        if(deviceIDs[i] == newDeviceIDs[j]) {
          exist = true;
          break;
        }
      }

      if(!exist) {
        newDeviceIDs.push(deviceIDs[i]);
      }
    }
    
    newFilter.setDeviceidsList(newDeviceIDs);

    await connectMaster.setAcceptFilter(mainMenu.getGatewayID(), newFilter);
    await showAcceptFilter();
  } catch (err) {
    console.error('Cannot add devices to the filter: ', err);
  }
}

5. Connection status

Apart from ConnectMaster.GetDeviceList, you can also get the realtime update using ConnectMaster.SubscribeStatus.

function subscribe(queueSize) {
  var req = new connectMasterMessage.SubscribeStatusRequest();
  req.setQueuesize(queueSize);

  return connMasterClient.subscribeStatus(req);
}
var sub = connectMaster.subscribe(QUEUE_SIZE);
cli.setSubChannel(sub);

sub.on('data', (status) => {
  var devStatus = status.getStatus();

  switch(devStatus) {
    case connect.connectMessage.Status.DISCONNECTED:
      console.log('\n[Disconnected]: ', status.toObject());
      break;

    case connect.connectMessage.Status.TCP_CONNECTED:
      console.log('\n[TCP Connected]: ', status.toObject());
      break;

    case connect.connectMessage.Status.TLS_CONNECTED:
      console.log('\n[TLS Connected]: ', status.toObject());
      break;
  }
});

sub.on('end', () => {
  console.log('Subscription is finished');
});

sub.on('error', (err) => {
  if(err.details === 'Cancelled') {
    console.log("Subscription is cancelled");
  } else {
    console.log('Subscription error: ', err);
  }
})

6. Connection mode

function setConnectionMode(deviceIDs, mode) {
  var req = new connectMasterMessage.SetConnectionModeMultiRequest();
  req.setDeviceidsList(deviceIDs);
  req.setConnectionmode(mode);

  return new Promise((resolve, reject) => {
    connectMaster.getClient().setConnectionModeMulti(req, (err, response) => {
      resolve(response);
    });
  });
}

After setting the connection mode, you have to use different APIs accordingly. With SERVER_TO_DEVICE, you should use the Synchronous APIs or the Asynchronous APIs. to connect to the devices. With DEVICE_TO_SERVER, the AcceptFilter should be configured correctly.

7. SSL

TLS 1.2 can be used for more secure communication between the gateway and devices. Refer to Secure Communication for details.

function enableSSL(deviceIDs) {
  var req = new connectMasterMessage.EnableSSLMultiRequest();
  req.setDeviceidsList(deviceIDs);

  return new Promise((resolve, reject) => {
    connectMaster.getClient().enableSSLMulti(req, (err, response) => {
      resolve(response);
    });
  });
}


function disableSSL(deviceIDs) {
  var req = new connectMasterMessage.DisableSSLMultiRequest();
  req.setDeviceidsList(deviceIDs);

  return new Promise((resolve, reject) => {
    connectMaster.getClient().disableSSLMulti(req, (err, response) => {
      resolve(response);
    });
  });
}