在树莓派上玩 K3s：从安装到实战，打造你的私人 Kubernetes 集群

curl -sfL https://get.k3s.io | sh -

# 查看节点状态
sudo kubectl get nodes

# 输出示例：
# NAME         STATUS   ROLES                  AGE   VERSION
# k3s-master   Ready    control-plane,master   1m    v1.28.5+k3s1

# 查看所有 Pod
sudo kubectl get pods -A

# 复制配置文件到用户目录
mkdir -p ~/.kube
sudo cp /etc/rancher/k3s/k3s.yaml ~/.kube/config
sudo chown $(id -u):$(id -g) ~/.kube/config

# 设置环境变量
echo 'export KUBECONFIG=~/.kube/config' >> ~/.bashrc
source ~/.bashrc

# 现在可以不用 sudo 了
kubectl get nodes

# 在树莓派上
sudo cat /etc/rancher/k3s/k3s.yaml

server: https://192.168.1.xxx:6443

sudo cat /var/lib/rancher/k3s/server/node-token

curl -sfL https://get.k3s.io | K3S_URL=https://192.168.1.xxx:6443 K3S_TOKEN=<上面获取的token> sh -

kubectl get nodes
# 应该看到多个节点

# pihole.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: pihole
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: pihole
  namespace: pihole
spec:
  replicas: 1
  selector:
    matchLabels:
      app: pihole
  template:
    metadata:
      labels:
        app: pihole
    spec:
      containers:
      - name: pihole
        image: pihole/pihole:latest
        env:
        - name: TZ
          value: "Asia/Shanghai"
        - name: WEBPASSWORD
          value: "your-secure-password"
        ports:
        - containerPort: 80
          name: http
        - containerPort: 53
          name: dns-tcp
          protocol: TCP
        - containerPort: 53
          name: dns-udp
          protocol: UDP
        volumeMounts:
        - name: pihole-config
          mountPath: /etc/pihole
      volumes:
      - name: pihole-config
        hostPath:
          path: /opt/pihole
          type: DirectoryOrCreate
---
apiVersion: v1
kind: Service
metadata:
  name: pihole
  namespace: pihole
spec:
  type: LoadBalancer
  selector:
    app: pihole
  ports:
  - name: http
    port: 80
    targetPort: 80
  - name: dns-tcp
    port: 53
    targetPort: 53
    protocol: TCP
  - name: dns-udp
    port: 53
    targetPort: 53
    protocol: UDP

kubectl apply -f pihole.yaml

# 查看状态
kubectl get pods -n pihole
kubectl get svc -n pihole

# nginx-demo.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-demo
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx-demo
  template:
    metadata:
      labels:
        app: nginx-demo
    spec:
      containers:
      - name: nginx
        image: nginx:alpine
        ports:
        - containerPort: 80
        resources:
          requests:
            cpu: 50m
            memory: 64Mi
          limits:
            cpu: 100m
            memory: 128Mi
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-demo
spec:
  type: NodePort
  selector:
    app: nginx-demo
  ports:
  - port: 80
    targetPort: 80
    nodePort: 30080
---
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: nginx-demo-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: nginx-demo
  minReplicas: 2
  maxReplicas: 5
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 50

kubectl apply -f nginx-demo.yaml

# 访问
curl http://<树莓派IP>:30080

# 查看 HPA 状态
kubectl get hpa

传感器 → 树莓派 GPIO → Pod (数据采集) → Pod (MQTT Broker) → 云端

# 用 raspi-config 配置启动顺序
sudo raspi-config
# Advanced Options → Boot Order → USB Boot

# ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-app-ingress
  annotations:
    traefik.ingress.kubernetes.io/router.entrypoints: web
spec:
  rules:
  - host: myapp.local
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: my-app
            port:
              number: 80

# K3s 默认用 SQLite，数据在这里
/var/lib/rancher/k3s/server/db/

# 简单备份
sudo cp -r /var/lib/rancher/k3s/server/db/ ~/k3s-backup-$(date +%Y%m%d)

# 看看原因
kubectl describe pod <pod-name>

# 常见原因：
# 1. 资源不足：检查 requests/limits 配置
# 2. 存储问题：PVC 没有对应的 PV
# 3. 镜像拉取失败：检查网络或镜像名

# 卸载 Server 节点
/usr/local/bin/k3s-uninstall.sh

# 卸载 Agent 节点
/usr/local/bin/k3s-agent-uninstall.sh