Kubernetes入门与实战部署

Kubernetes入门与实战部署

Kubernetes（K8s）是当前最流行的容器编排平台，它可以自动化容器的部署、扩展和管理。虽然学习曲线较陡，但掌握K8s是现代云原生开发的必备技能。本文将介绍K8s的核心概念和实战部署方法。

一、核心概念

# Pod - 最小部署单元
apiVersion: v1
kind: Pod
metadata:
  name: myapp-pod
spec:
  containers:
  - name: app
    image: myapp:latest
    ports:
    - containerPort: 8080
    resources:
      requests:
        memory: "128Mi"
        cpu: "250m"
      limits:
        memory: "256Mi"
        cpu: "500m"
    livenessProbe:
      httpGet:
        path: /health
        port: 8080
      initialDelaySeconds: 30
      periodSeconds: 10
    readinessProbe:
      httpGet:
        path: /ready
        port: 8080
      initialDelaySeconds: 5
      periodSeconds: 5

二、Deployment与Service

# Deployment - 管理Pod副本集
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - name: myapp
        image: myapp:v1
        ports:
        - containerPort: 8080

---

# Service - 暴露服务
apiVersion: v1
kind: Service
metadata:
  name: myapp-service
spec:
  selector:
    app: myapp
  ports:
  - port: 80
    targetPort: 8080
  type: ClusterIP

三、Ingress与配置管理

# Ingress - HTTP路由
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myapp-ingress
  annotations:
    nginx.ingress.kubernetes.io/ssl-redirect: "true"
spec:
  tls:
  - hosts:
    - myapp.example.com
    secretName: tls-secret
  rules:
  - host: myapp.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: myapp-service
            port:
              number: 80

# ConfigMap - 配置文件
apiVersion: v1
kind: ConfigMap
metadata:
  name: app-config
data:
  DATABASE_HOST: "mysql-service"
  REDIS_HOST: "redis-service"
  APP_ENV: "production"

四、常用命令

# 部署相关
kubectl apply -f deployment.yaml
kubectl get pods
kubectl describe pod myapp-pod
kubectl logs myapp-pod -f
kubectl exec -it myapp-pod -- /bin/sh

# 扩缩容
kubectl scale deployment myapp --replicas=5
kubectl autoscale deployment myapp --min=2 --max=10 --cpu-percent=80

# 更新与回滚
kubectl set image deployment/myapp myapp=myapp:v2
kubectl rollout status deployment/myapp
kubectl rollout undo deployment/myapp
kubectl rollout history deployment/myapp

# 调试
kubectl get events --sort-by=.metadata.creationTimestamp
kubectl top pods
kubectl top nodes

Kubernetes是容器编排的事实标准，学习它需要时间和实践。建议从Minikube本地环境开始，逐步掌握Pod、Service、Deployment等核心概念，再深入到Ingress、存储和网络等高级主题。