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75_Bare_Metal_Kubernetes_KubeEdge_Edge_Nodes

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DEPLOYMENT 75 — Bare Metal → Kubernetes → KubeEdge → Edge Nodes

Deployment Stack Overlay

┌──────────────────────────────────────────────────┐
│             Workload (App/Process)             │
├──────────────────────────────────────────────────┤
│                   Edge Nodes                   │
├──────────────────────────────────────────────────┤
│                    KubeEdge                    │
├──────────────────────────────────────────────────┤
│                   Kubernetes                   │
├──────────────────────────────────────────────────┤
│                   Bare Metal                   │
└──────────────────────────────────────────────────┘

Detailed System Infrastructure

┌─────────────────────────────────────────────────────────────────┐
│              CLOUD MANAGEMENT LAYER                             │
│  ┌──────────────────────────────────────────────────────────┐   │
│  │  kubectl (manages both cloud and edge nodes uniformly)   │   │
│  │  Cloud K8s cluster (control plane for all edge nodes)    │   │
│  └──────────────────────────────────────────────────────────┘   │
└────────────────────────────┬────────────────────────────────────┘
                             │  WebSocket tunnel (HTTPS)
┌────────────────────────────▼────────────────────────────────────┐
│              KUBEEDGE CLOUD SIDE (runs in cloud K8s)            │
│  ┌──────────────────────────────────────────────────────────┐   │
│  │  CloudCore (KubeEdge cloud component — K8s pod)          │   │
│  │  ┌────────────────────────────────────────────────────┐  │   │
│  │  │  EdgeHub — manages WebSocket connections to edges  │  │   │
│  │  │  EdgeController — syncs K8s resources to edges     │  │   │
│  │  │  DeviceController — IoT device twin management     │  │   │
│  │  └────────────────────────────────────────────────────┘  │   │
│  └──────────────────────────────────────────────────────────┘   │
└────────────────────────────┬────────────────────────────────────┘
                             │  WebSocket (works through NAT/firewall)
┌────────────────────────────▼────────────────────────────────────┐
│              EDGE NODE (remote location — may be offline)       │
│  ┌──────────────────────────────────────────────────────────┐   │
│  │  EdgeCore (KubeEdge edge component)                      │   │
│  │  ┌────────────────────────────────────────────────────┐  │   │
│  │  │  Edged — local kubelet-like pod manager            │  │   │
│  │  │  EdgeHub — WebSocket client to CloudCore           │  │   │
│  │  │  EventBus — MQTT broker for IoT device events      │  │   │
│  │  │  DeviceTwin — local digital twin for IoT devices   │  │   │
│  │  │  MetaManager — local metadata cache (works offline)│  │   │
│  │  └────────────────────────────────────────────────────┘  │   │
│  │  ┌────────────────────────────────────────────────────┐  │   │
│  │  │  Edge Pods (containers on edge node)               │  │   │
│  │  │  ┌──────────────────────────────────────────────┐  │  │   │
│  │  │  │  AI/ML inference (TensorFlow Lite pod)       │  │  │   │
│  │  │  │  IoT data aggregator pod                     │  │  │   │
│  │  │  │  Protocol adapter pod (Modbus/OPC-UA bridge) │  │  │   │
│  │  │  └──────────────────────────────────────────────┘  │  │   │
│  │  └────────────────────────────────────────────────────┘  │   │
│  │  ┌────────────────────────────────────────────────────┐  │   │
│  │  │  IoT DEVICES (connected to edge node)              │  │   │
│  │  │  Sensors │ Cameras │ PLCs │ Industrial equipment   │  │   │
│  │  └────────────────────────────────────────────────────┘  │   │
│  └──────────────────────────────────────────────────────────┘   │
└────────────────────────────┬────────────────────────────────────┘
                             │
┌────────────────────────────▼────────────────────────────────────┐
│                       BARE METAL (Edge Hardware)                │
│  Raspberry Pi / Jetson Nano / Industrial PC / ARM SBC           │
│  CPU (ARM64 or x86) │ RAM 2GB+ │ Flash/eMMC │ WiFi/LTE/Eth     │
└─────────────────────────────────────────────────────────────────┘

Technical Implementation Details

  • Networking: Uses CNI plugins (Calico/Cilium) for pod-to-pod communication.
  • Storage: Persistent Volumes (PV) managed via CSI drivers.
  • Management: Orchestrated via native CLI or high-level API controllers.

How It Works

  • CloudCore runs in the central cloud K8s cluster and manages all edge nodes
  • EdgeCore runs on each edge device and registers with CloudCore via WebSocket
  • EdgeCore's MetaManager caches pod specs and device configs locally — pods continue running even if cloud is unreachable
  • DeviceTwin provides a digital twin for each IoT device (reported state + desired state)
  • EventBus bridges MQTT from IoT devices into K8s events visible at the cloud level
  • kubectl from the cloud can list and manage pods on remote edge nodes

Use Case

Industrial IoT, smart manufacturing, autonomous vehicles, smart cities — where Kubernetes-managed containers need to run at remote locations with unreliable connectivity.

Pros

  • Works offline — edge pods survive cloud disconnection
  • Kubernetes API consistency from cloud to edge
  • IoT device twin management built-in
  • CNCF project with active community

Cons

  • WebSocket tunnel — limited throughput vs direct K8s
  • Limited edge node resources vs cloud K8s features
  • Complex debug across cloud-edge boundary
  • MQTT bridging adds complexity for IoT
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