Kubernetes Install

When to Use Each Option

Running the Device Agent in Kubernetes is appropriate when devices are containerized or managed as part of a Kubernetes-based edge or infrastructure platform.

Choose your deployment pattern based on how you manage device identity:

• Fixed Configuration
  Use when the device already exists in FlowFuse and you have a device.yml with its credentials. One deployment maps to one device identity.
• Automatic Provisioning
  Use when devices should register themselves at startup using a Provisioning Token. Each instance requires writable persistent storage.

Any deployment on Kubernetes is going to be specific to the environment and requirements of the solution. The following examples show two common patterns for running the FlowFuse Device Agent on Kubernetes:

• Fixed configuration using a static device.yml
• Automatic provisioning using a FlowFuse Provisioning Token

Choose the approach that matches how you manage device lifecycle and credentials.

Fixed Configuration

If you have an existing device.yml file containing a set of Device Agent credentials.

kubectl create secret generic device-one-secret --from-file=device.yml=./device.yml

The following manifest will create a Deployment and Service for a device using the supplied Secret as its credentials

apiVersion: apps/v1
kind: Deployment
metadata:
  name: device-one
  labels:
    app: device-one
spec:
  replicas: 1 # there can only be one replica as there is one configuration
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: device-one
  template:
    metadata:
      labels:
        app: device-one
    spec:
      containers:
      - name: device-one
        image: flowfuse/device-agent:latest
        ports:
        - containerPort: 1880
        volumeMounts:
        - name: config
          mountPath: "/opt/flowfuse-device/device.yml"
          subPath: "device.yml"
          readOnly: true
        resources:
          limits:
            cpu: 1000m
            memory: 256Mi
          requests:
            cpu: 500m
            memory: 128Mi
      volumes:
      - name: config
        secret:
          secretName: device-one-secret
---
apiVersion: v1
kind: Service
metadata:
  name: device-one-service
spec:
  selector:
    app: device-one
  ports:
  - protocol: TCP
    port: 1880
    targetPort: 1880

Automatic Provisioning

Using a FlowFuse Provisioning Token to automatically configure a new Device Agent on deployment.

Because the Device Agent will need to re-write the device.yml file it can no longer be stored in a Secret and a PersistentVolume must be used for each instance of the Device Agent.

A Secret is used to hold the initial device.yml which contains the provisioning token.

kubectl create secret generic device-provisioning-secret --from-file=device.yml=./device.yml

The following manifest will create a Deployment, Service and PVC for a device using the supplied Secret as the source of the Provisioning token.

The PVC will be used to store the updated device.yml and the Node-RED nodes installed by the Remote Instance.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: device-one
  labels:
    app: device-one
spec:
  replicas: 1 # to scale to more than one instance you should modify this to use a StatefulSet
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: device-one
  template:
    metadata:
      labels:
        app: device-one
    spec:
      initContainers: # on first run copies the device.yml from Secret to PVC volume
      - name: config-copy
        image: busybox:latest
        command: 
        - "/bin/sh"
        - "-c"
        - "if [ ! -f /opt/flowfuse-device/device.yml ]; then cp /tmp/device.yml /opt/flowfuse-device/device.yml; fi"
        volumeMounts:
        - name: config
          mountPath: "/opt/flowfuse-device"
        - name: initial-config
          mountPath: "/tmp/device.yml"
          subPath: "device.yml"
          readOnly: true
      containers:
      - name: device-one
        image: flowfuse/device-agent:latest
        ports:
        - containerPort: 1880
        volumeMounts:
        - name: config
          mountPath: "/opt/flowfuse-device"
        resources:
          limits:
            cpu: 1000m
            memory: 256Mi
          requests:
            cpu: 500m
            memory: 128Mi
      volumes:
      - name: initial-config
        secret:
          secretName: device-provisioning-secret
      - name: config
        persistentVolumeClaim:
          claimName: device-one-pvc
        
---
apiVersion: v1
kind: Service
metadata:
  name: device-one-service
spec:
  selector:
    app: device-one
  ports:
  - protocol: TCP
    port: 1880
    targetPort: 1880
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: device-one-pvc
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi