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Connect a HTTP Device via LwM2M Gateway

LwM2M Gateway Introduction​

The LwM2M (Lightweight Machine to Machine) Gateway consists of two main components: an LwM2M client that connects to the LwM2M server and an HTTP client that connects to deviceShifu.The LwM2M Gateway enables deviceShifu to adapt to the LwM2M protocol,handle requests from the LwM2M server, and push data to the cloud, fulfilling the two major functions required by the LwM2M protocol: the capability to pull data from the device and post data from the cloud to the device.

Deploy deviceShifu-HTTP and LwM2M-gateway​

Using lwm2m_gw_http as an example, to implement connecting a HTTP Device via LwM2M Gateway, you need to configure and deploy the corresponding edgedevice, deviceShifu, and LwM2M-gateway. Below are the reference configurations:

Configure the edgedevice.yaml​

Before device integration, you need to edit the device's edgedevice.yaml file. In this case, we're modifying lwm2m_gw_http\deviceshifu-thermometer\thermometer-edgedevice.yaml.

...
spec:
  sku: "Thermometer" 
  connection: Ethernet           # Device network connection method
  address: 192.168.1.100:11111   # Device network address
  protocol: HTTP                 # Communication protocol between gateway and device
  gatewaySettings:               # Additional gateway configuration settings
...

For gatewaySettings, we need to further configure the device Gateway Configuration for LwM2M-server Integration.

Configure deviceShifu's configmap.yaml​

Before gateway integration, we need to configure the commands that the gateway can receive in deviceShifu, along with corresponding instance objects (ObjectId) and data types (DataType). Additionally, we need to configure deviceShifu telemetry settings to enable periodic data collection and transmission to the LwM2M-server. In this case, we're modifying deviceshifu-thermometer\deviceshifu-thermometer-configmap.yaml

...
  instructions: |
    instructionSettings:
      defaultTimeoutSeconds: 8
    instructions:
      read_value:                  # The name of the command you want to set
        gatewayPropertyList:
          ObjectId: /3442/0/130    # Device instance object ID
          DataType: float          # Data type
...

Configure LwM2M-gateway Settings​

After configuring deviceShifu, we need to set up corresponding configurations on the Gateway side. In this case, we're modifyingdeviceshifu-lwm2m\lwm2m-deviceshifu-configmap.yaml

...
  instructions: |
    instructions:
      read_value:                  # Corresponding configuration
        protocolPropertyList:
          ObjectId: /3442/0/130
          EnableObserve: false

Deploy LwM2M deviceShifu​

We'll take connecting a HTTP-based thermometer as an example. Below is the general data flow of our access:

  1. First, we deploy the corresponding LwM2M gateway. The code is located in examples/lwm2m_gw_http/deviceshifu-lwm2m. Let's deploy them in the cluster.
kubectl apply -f examples/lwm2m_gw_http/deviceshifu-lwm2m
  1. Deploy and run the Device Adapter: deviceShifu-HTTP
kubectl apply -f examples/lwm2m_gw_http/deviceshifu-thermometer
  1. Ensure device connection. Our example includes a virtual thermometer device for your testing convenience.

The kubectl command allows you to view the status of deviceShifu:

$ kubectl get pods -n deviceshifu
NAME                                                 READY   STATUS    RESTARTS      AGE
deviceshifu-lwm2m-deployment-794ddd9978-z7lcq        1/1     Running   2 (44m ago)   44m
deviceshifu-thermometer-deployment-b98fbbcf8-6g69b   2/2     Running   3 (42m ago)   43m

Running Results​

We can check our service status using the following command:

$ kubectl get svc -n deviceshifu
NAME                        TYPE           CLUSTER-IP     EXTERNAL-IP   PORT(S)                       AGE
deviceshifu-lwm2m-service   NodePort       10.43.47.30    <none>        80:30080/TCP,5683:30000/UDP   47m
deviceshifu-thermometer     LoadBalancer   10.43.64.126   <pending>     80:31703/TCP                  46m

We can start an Nginx container and perform a simple test:

kubectl exec -it nginx -n deviceshifu -- bash

The following is to get the value through LwM2M-gateway:

$ curl deviceshifu-lwm2m-servicece.deviceshifu.svc.cluster.local/read_value
{"bn":"/3442/0/130/","e":[{"v":19}]}