K3S速度上手找点感觉

K3S 两天速通指南

│ ARM64 / 8核16G 环境 · K3S v1.36.3+k3s1

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Day 1：装好 + 跑起来

1. 安装（一条命令）

# 安装 K3S
官方源：curl -sfL https://get.k3s.io | sh -

用国内源：curl -sfL https://rancher-mirror.rancher.cn/k3s/k3s-install.sh | \
INSTALL_K3S_MIRROR=cn sh -s - \
--system-default-registry "registry.cn-hangzhou.aliyuncs.com"

# 验证
k3s kubectl get nodes
# 看到 Ready 就成功了

# 配置 kubectl 快捷使用
ln -s /usr/local/bin/k3s /usr/local/bin/kubectl
mkdir -p ~/.kube && cp /etc/rancher/k3s/k3s.yaml ~/.kube/config

2. 跑个 Nginx 试试

# 部署 3 个 Nginx
kubectl create deployment nginx --image=nginx:alpine --replicas=3

# 看看 Pod
kubectl get pods -o wide

# 暴露服务（K3S 自带负载均衡，直接用）
kubectl expose deployment nginx --port=80 --type=LoadBalancer

# 拿到 IP 访问
kubectl get svc nginx
# curl http://<EXTERNAL-IP>

3. 常用操作找感觉

# 扩缩容
kubectl scale deployment nginx --replicas=5
kubectl get pods -w          # 实时看 Pod 变化，Ctrl+C 退出

# 缩回去
kubectl scale deployment nginx --replicas=1

# 更新镜像
kubectl set image deployment/nginx nginx=nginx:1.25-alpine
kubectl rollout status deployment/nginx

# 回滚
kubectl rollout undo deployment/nginx

# 进容器看看
kubectl exec -it $(kubectl get pods -l app=nginx -o jsonpath='{.items[0].metadata.name}') -- sh

# 看日志
kubectl logs -f deployment/nginx

# 删掉
kubectl delete deployment nginx

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Day 2：存储 + 配置 + Ingress

4. 存储试试（K3S 自带 local-path）

# 创建一个带持久存储的 Pod
cat << 'YAML' | kubectl apply -f -
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: data-pvc
spec:
  accessModes: ["ReadWriteOnce"]
  resources:
    requests:
      storage: 1Gi
---
apiVersion: v1
kind: Pod
metadata:
  name: storage-demo
spec:
  containers:
  - name: web
    image: nginx:alpine
    volumeMounts:
    - name: data
      mountPath: /usr/share/nginx/html
  volumes:
  - name: data
    persistentVolumeClaim:
      claimName: data-pvc
YAML

# 写点数据进去
kubectl exec storage-demo -- sh -c 'echo "<h1>Hello K3S</h1>" > /usr/share/nginx/html/index.html'

# 查看 PVC
kubectl get pvc

5. ConfigMap 和 Secret

# ConfigMap - 管配置
kubectl create configmap app-config \
  --from-literal=ENV=prod --from-literal=PORT=8080

# Secret - 管密码
kubectl create secret generic db-cred \
  --from-literal=user=admin --from-literal=pass=secret123

# 看看（Secret 不会显示明文）
kubectl get configmap app-config -o yaml
kubectl get secret db-cred -o yaml

6. Ingress 路由（K3S 自带 Traefik）

# 先部署两个服务
kubectl create deployment app1 --image=nginx:alpine
kubectl expose deployment app1 --port=80
kubectl exec deployment/app1 -- sh -c 'echo "App1" > /usr/share/nginx/html/index.html'

kubectl create deployment app2 --image=nginx:alpine
kubectl expose deployment app2 --port=80
kubectl exec deployment/app2 -- sh -c 'echo "App2" > /usr/share/nginx/html/index.html'

# 用 Ingress 按路径路由
cat << 'YAML' | kubectl apply -f -
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
spec:
  rules:
  - http:
      paths:
      - path: /app1
        pathType: Prefix
        backend:
          service:
            name: app1
            port:
              number: 80
      - path: /app2
        pathType: Prefix
        backend:
          service:
            name: app2
            port:
              number: 80
YAML

# 测试路由
kubectl get ingress
# curl http://<节点IP>/app1  → App1
# curl http://<节点IP>/app2  → App2

7. 看看资源占用

kubectl top nodes
kubectl top pods

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速查表

kubectl get pods -A              # 看所有 Pod
kubectl get svc                  # 看服务
kubectl get ingress              # 看路由
kubectl logs -f <pod>            # 看日志
kubectl exec -it <pod> -- sh     # 进容器
kubectl describe pod <pod>       # 排查问题
kubectl delete <资源> <名字>      # 删除
kubectl scale deploy <名> --replicas=N  # 扩缩容

卸载

/usr/local/bin/k3s-uninstall.sh