Kubernetes（容器编排平台）

# 方式 1：安装 Minikube（本地单节点集群，推荐初学者）
# macOS
brew install minikube

# Windows (使用 winget)
winget install Kubernetes.minikube

# Linux
curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
sudo install minikube-linux-amd64 /usr/local/bin/minikube

# 方式 2：Docker Desktop 内置 Kubernetes
# 打开 Docker Desktop → Settings → Kubernetes → 勾选 Enable Kubernetes

# 安装 kubectl（与 K8s 集群交互的命令行工具）
# macOS
brew install kubectl
# Windows
winget install Kubernetes.kubectl

# 启动本地集群（Minikube 方式）
minikube start

# 验证集群连接
kubectl cluster-info
kubectl get nodes

# 第一步：创建 Deployment 配置文件
cat > hello-agent.yaml << 'EOF'
apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello-agent
spec:
  replicas: 3                      # 运行 3 个副本
  selector:
    matchLabels:
      app: hello-agent
  template:
    metadata:
      labels:
        app: hello-agent
    spec:
      containers:
      - name: web
        image: nginx:1.27-alpine   # 用 nginx 做演示
        ports:
        - containerPort: 80
        resources:
          requests:                 # 最低资源保障
            memory: "64Mi"
            cpu: "50m"
          limits:                   # 资源上限
            memory: "128Mi"
            cpu: "100m"
---
apiVersion: v1
kind: Service
metadata:
  name: hello-agent-svc
spec:
  type: NodePort                   # 通过节点端口对外暴露
  selector:
    app: hello-agent
  ports:
  - port: 80
    targetPort: 80
EOF

# 第二步：部署到集群
kubectl apply -f hello-agent.yaml

# 第三步：查看运行状态
kubectl get deployments
kubectl get pods
kubectl get services

# 第四步：访问服务（Minikube 环境）
minikube service hello-agent-svc --url

# 第五步：扩容到 5 个副本
kubectl scale deployment hello-agent --replicas=5
kubectl get pods    # 观察新 Pod 创建过程

# 第六步：清理资源
# kubectl delete -f hello-agent.yaml

$ kubectl get deployments
NAME          READY   UP-TO-DATE   AVAILABLE   AGE
hello-agent   3/3     3            3           30s

$ kubectl get pods
NAME                           READY   STATUS    RESTARTS   AGE
hello-agent-5d7b8f6c4a-abc12   1/1     Running   0          30s
hello-agent-5d7b8f6c4a-def34   1/1     Running   0          30s
hello-agent-5d7b8f6c4a-ghi56   1/1     Running   0          30s

$ kubectl get services
NAME              TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
hello-agent-svc   NodePort   10.96.145.200   <none>        80:31234/TCP   25s