Kubernetes NetworkPolicy 双向隔离与命名空间选择器实战

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title: Kubernetes NetworkPolicy 双向隔离与命名空间选择器实战

keywords: NetworkPolicy, namespaceSelector, podSelector, policyTypes, DNS egress

description: 通过 NetworkPolicy 实现后端命名空间的双向隔离，仅允许指定前端命名空间访问，同时保留 DNS 出口。

categories:

• 文章资讯
• 技术教程

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为命名空间打标签（便于选择）：

kubectl label namespace frontend name=frontend --overwrite
kubectl label namespace backend name=backend --overwrite

后端命名空间的 NetworkPolicy：

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: backend-iso
  namespace: backend
spec:
  podSelector:
    matchLabels:
      app: api
  policyTypes:
  - Ingress
  - Egress
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          name: frontend
  egress:
  - to:
    - namespaceSelector:
        matchLabels:
          kubernetes.io/metadata.name: kube-system
      podSelector:
        matchLabels:
          k8s-app: kube-dns
    ports:
    - protocol: UDP
      port: 53
    - protocol: TCP
      port: 53