Kubernetes 入门与实战

一、核心概念

1.1 Pod

apiVersion: v1
kind: Pod
metadata:
  name: myapp-pod
  labels:
    app: myapp
spec:
  containers:
    - name: myapp
      image: nginx:latest
      ports:
        - containerPort: 80
      resources:
        requests:
          memory: "128Mi"
          cpu: "250m"
        limits:
          memory: "256Mi"
          cpu: "500m"

1.2 Service

apiVersion: v1
kind: Service
metadata:
  name: myapp-service
spec:
  selector:
    app: myapp
  ports:
    - port: 80
      targetPort: 80
      nodePort: 30007
  type: NodePort

1.3 Deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
        - name: myapp
          image: nginx:latest
          ports:
            - containerPort: 80

二、高级配置

2.1 ConfigMap

apiVersion: v1
kind: ConfigMap
metadata:
  name: myapp-config
data:
  DB_HOST: "mysql-service"
  DB_PORT: "3306"
  DEBUG: "false"

2.2 Secret

apiVersion: v1
kind: Secret
metadata:
  name: myapp-secret
type: Opaque
data:
  DB_PASSWORD: cGFzc3dvcmQ=
  API_KEY: YXBpa2V5MTIzNA==

2.3 Ingress

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myapp-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
    - host: example.com
      http:
        paths:
          - path: /app
            pathType: Prefix
            backend:
              service:
                name: myapp-service
                port:
                  number: 80

三、运维命令

# 查看资源
kubectl get pods
kubectl get services
kubectl get deployments
kubectl get nodes

# 查看详情
kubectl describe pod myapp-pod
kubectl describe service myapp-service

# 日志
kubectl logs myapp-pod
kubectl logs -f myapp-pod

# 进入容器
kubectl exec -it myapp-pod -- bash

# 端口转发
kubectl port-forward myapp-pod 8080:80

# 扩展副本
kubectl scale deployment myapp-deployment --replicas=5

# 滚动更新
kubectl set image deployment/myapp-deployment myapp=nginx:1.24

# 回滚
kubectl rollout undo deployment/myapp-deployment

四、常用配置

4.1 资源限制

apiVersion: v1
kind: LimitRange
metadata:
  name: resource-limit
spec:
  limits:
    - default:
        memory: 256Mi
        cpu: 500m
      defaultRequest:
        memory: 128Mi
        cpu: 250m
      type: Container

4.2 节点选择

apiVersion: v1
kind: Pod
metadata:
  name: myapp-pod
spec:
  nodeSelector:
    disk: ssd
    zone: us-east-1a

提示：所有文章内容均为实战经验总结，部分示例来自官方文档和社区最佳实践。

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