[Question]An error occurred when using the Modbus Service and Openyurt to connect to a real sensor！

[HuangYuFe]

What happened:
I tried to use the EdgeX project to complete the integration of real sensor devices based on the ModbusRTU protocol. I completed the deployment of EdgeX using Openyurt' Deployment deployer。

In addition, I have completed the access of real sensor devices based on ModbusTCP, which can complete the data collection.

But when I try to collect ModbusRTU device data via the USB hardware interface, I get a problem.

What you expected to happen:
I checked the deployment information of the EdgeX application according to the permission denial prompted by the log message, and I confirmed that the mount path is /dev/ttyUSB0 and I have the r/w permission.

So, it's not clear to me what the cause of the error is, here's the YAML content of my Openyurt deployer:

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?:


Environment:

• OpenYurt version:v1.4
• Kubernetes version (use kubectl version):1.22.4
• OS (e.g: cat /etc/os-release):Ubuntu 20.04.6 LTS
• Kernel (e.g. uname -a):Linux orangepi5plus 6.1.43-rockchip-rk3588
• Install tools:
• Others:

others
/kind question

[rambohe-ch]

@LavenderQAQ PTAL

[LavenderQAQ]

@HuangYuFe Hello, could you please provide the version of EdgeX you are using?

[HuangYuFe]

@HuangYuFe Hello, could you please provide the version of EdgeX you are using?

@LavenderQAQ The version of EdgeX I'm using is levski, and both of them have image versions 2.3.0

[HuangYuFe]

@LavenderQAQ
For the access of ModbusRTU devices, I refer to the official EdgeX manual, but the official deployment is done in the way of DockerCompose, mounting directories, and permissions are all completed through Linux instructions. But this way I tried it and it didn't work. Previously, we discussed with Openyurt that when changing the Service to a NodePort type, the Linux command operation is invalid. At that time, it was achieved by modifying the cm platformadmin-framework provided by Openyurt. So, this time, I also tried to add a mount path and permission upgrade in CM platformadmin-framework.

[LavenderQAQ]

@HuangYuFe Try using a privileged container. Reading and writing to a real device inside a container may require enabling privileges.

apiVersion: v1
kind: Pod
metadata:
  name: privileged-pod
spec:
  containers:
  - name: privileged-container
    image: your-image
    securityContext:
      privileged: true

[HuangYuFe]

@LavenderQAQ Yes, I also took this into account afterwards and modified the YMAL file as follows:

    - deployment:
        selector:
          matchLabels:
            app: edgex-device-modbus
        strategy: {}
        template:
          metadata:
            creationTimestamp: null
            labels:
              app: edgex-device-modbus
          spec:
            initContainers:
            - name: init-permissions
              image: edgexfoundry/device-modbus-arm64:2.3.0
              command: ["sh", "-c",  "chown :0 /dev/ttyUSB0"]
              volumeMounts:
              - name: devices
                mountPath: /dev/ttyUSB0
            containers:
            - env:
              - name: SERVICE_HOST
                value: edgex-device-modbus
              envFrom:
              - configMapRef:
                  name: common-variables
              image: edgexfoundry/device-modbus-arm64:2.3.0
              imagePullPolicy: IfNotPresent
              name: edgex-device-modbus
              ports:
              - containerPort: 59901
                name: tcp-59901
                protocol: TCP
              resources: {}
              volumeMounts:
              - name: devices
                mountPath: /dev/ttyUSB0
              securityContext:
                privileged: true
                runAsUser: 0
            hostname: edgex-device-modbus
          volumes:
          - name: devices
            hostPath:
              path: /dev/ttyUSB0
      name: edgex-device-modbus
      service:
        ports:
        - name: tcp-59901
          port: 59901
          protocol: TCP
          targetPort: 59901
        selector:
          app: edgex-device-modbus

After rebuilding the service, the same permission error is still reported.

ModbusTCP devices are available, ModbusRTU devices are not.