部署 coredns

创建部署文件 coredns.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: coredns
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: system:coredns
rules:
- apiGroups: [""]  # 核心 API 组
  resources:
  - endpoints
  - services
  - pods
  - namespaces
  verbs:
  - get
  - list
  - watch
- apiGroups: ["discovery.k8s.io"]  # discovery API 组
  resources:
  - endpointslices
  verbs:
  - get
  - list
  - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: system:coredns
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:coredns
subjects:
- kind: ServiceAccount
  name: coredns
  namespace: kube-system
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: coredns
  namespace: kube-system
data:
  Corefile: |
    .:53 {
        errors
        health {
          lameduck 5s
        }
        ready
        kubernetes cluster.local in-addr.arpa ip6.arpa {
          pods insecure
          fallthrough in-addr.arpa ip6.arpa
        }
        prometheus :9153
        forward . 223.5.5.5 223.6.6.6 8.8.8.8 8.8.4.4 {
          prefer_udp
          policy sequential
        }
        cache 30
        loop
        reload
        loadbalance
    }
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: coredns
  namespace: kube-system
  labels:
    k8s-app: kube-dns
spec:
  replicas: 2
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 1
  selector:
    matchLabels:
      k8s-app: kube-dns
  template:
    metadata:
      labels:
        k8s-app: kube-dns
    spec:
      serviceAccountName: coredns
      tolerations:
      - key: node-role.kubernetes.io/master
        effect: NoSchedule
      - key: node-role.kubernetes.io/control-plane
        effect: NoSchedule
      containers:
      - name: coredns
        image: coredns/coredns:1.9.3
        args: [ "-conf", "/etc/coredns/Corefile" ]
        env:
        - name: KUBERNETES_SERVICE_HOST
          value: "10.0.30.47"
        - name: KUBERNETES_SERVICE_PORT
          value: "6443"
        volumeMounts:
        - name: config-volume
          mountPath: /etc/coredns
        - name: host-resolv
          mountPath: /etc/resolv.conf
          readOnly: true
        ports:
        - containerPort: 53
          name: dns
          protocol: UDP
        - containerPort: 53
          name: dns-tcp
          protocol: TCP
        - containerPort: 9153
          name: metrics
          protocol: TCP
        securityContext:
          allowPrivilegeEscalation: false
          capabilities:
            add:
            - NET_BIND_SERVICE
            drop:
            - all
          readOnlyRootFilesystem: true
        livenessProbe:
          httpGet:
            path: /health
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 60
          timeoutSeconds: 5
          successThreshold: 1
          failureThreshold: 5
        readinessProbe:
          httpGet:
            path: /ready
            port: 8181
            scheme: HTTP
        resources:
          limits:
            memory: 170Mi
          requests:
            cpu: 100m
            memory: 70Mi
      volumes:
      - name: config-volume
        configMap:
          name: coredns
          items:
          - key: Corefile
            path: Corefile
      - name: host-resolv
        hostPath:
          path: /etc/resolv.conf
          type: File
---
apiVersion: v1
kind: Service
metadata:
  name: kube-dns
  namespace: kube-system
  labels:
    k8s-app: kube-dns
    kubernetes.io/name: "CoreDNS"
spec:
  selector:
    k8s-app: kube-dns
  clusterIP: 172.16.0.101
  ports:
  - name: dns
    port: 53
    protocol: UDP
  - name: dns-tcp
    port: 53
    protocol: TCP
  - name: metrics
    port: 9153
    protocol: TCP

部署 coredns

kubectl apply -f coredns.yaml