[问题已处理]-k8s的coredns突然变为unheathy

Bertha 。 2022-11-05 13:55 6阅读 0赞

导语：今天测试环境的coredns不知为何突然变成unhealthy了 删除pod无法恢复。应该是configmap改坏了

应该是添加自定义dns 的时候 edit 黏贴了 导致乱码了 可以用patch 替代 参考文档https://v1-19.docs.kubernetes.io/zh/docs/tasks/manage-kubernetes-objects/update-api-object-kubectl-patch/

可以通过如下操作恢复

# 先删除coredns的服务 svc 和deployment
    kubectl delete  deployment/coredns -n kube-system
    kubectl delete  svc/kube-dns -n kube-system
    
    # 如果需要删除account 可以用下面的脚本删除
    wget https://raw.githubusercontent.com/coredns/deployment/master/kubernetes/coredns.yaml.sed
    wget https://raw.githubusercontent.com/coredns/deployment/master/kubernetes/deploy.sh
    chmod +x deploy.sh
    ./deploy.sh | kubectl delete  -f -

创建新的coredns.yaml 如果需要添加自定义dns 最好使用patch

apiVersion: v1
    kind: ServiceAccount
    metadata:
      name: coredns
      namespace: kube-system
    ---
    apiVersion: rbac.authorization.k8s.io/v1
    kind: ClusterRole
    metadata:
      labels:
        kubernetes.io/bootstrapping: rbac-defaults
      name: system:coredns
    rules:
    - apiGroups:
      - ""
      resources:
      - endpoints
      - services
      - pods
      - namespaces
      verbs:
      - list
      - watch
    ---
    apiVersion: rbac.authorization.k8s.io/v1
    kind: ClusterRoleBinding
    metadata:
      annotations:
        rbac.authorization.kubernetes.io/autoupdate: "true"
      labels:
        kubernetes.io/bootstrapping: rbac-defaults
      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
            kubernetes cluster.local in-addr.arpa ip6.arpa {
               pods insecure
               upstream
               fallthrough in-addr.arpa ip6.arpa
            }
            hosts {
                192.168.1.216     rap.yjk.cn
                fallthrough
            }
            prometheus :9153
            proxy . /etc/resolv.conf
            cache 30
            loop
            reload
            loadbalance
        }
    ---
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      labels:
        k8s-app: kube-dns
      name: coredns
      namespace: kube-system
    spec:
      replicas: 1
      revisionHistoryLimit: 10
      selector:
        matchLabels:
          k8s-app: kube-dns
      strategy:
        rollingUpdate:
          maxSurge: 25%
          maxUnavailable: 1
        type: RollingUpdate
      template:
        metadata:
          labels:
            k8s-app: kube-dns
        spec:
          containers:
          - args:
            - -conf
            - /etc/coredns/Corefile
            image:  docker.io/fengyunpan/coredns:1.2.6
            imagePullPolicy: IfNotPresent
            livenessProbe:
              failureThreshold: 5
              httpGet:
                path: /health
                port: 8080
                scheme: HTTP
              initialDelaySeconds: 60
              periodSeconds: 10
              successThreshold: 1
              timeoutSeconds: 5
            name: coredns
            ports:
            - containerPort: 53
              name: dns
              protocol: UDP
            - containerPort: 53
              name: dns-tcp
              protocol: TCP
            - containerPort: 9153
              name: metrics
              protocol: TCP
            resources:
              limits:
                memory: 170Mi
              requests:
                cpu: 100m
                memory: 70Mi
            securityContext:
              allowPrivilegeEscalation: false
              capabilities:
                add:
                - NET_BIND_SERVICE
                drop:
                - all
              procMount: Default
              readOnlyRootFilesystem: true
            terminationMessagePath: /dev/termination-log
            terminationMessagePolicy: File
            volumeMounts:
            - mountPath: /etc/coredns
              name: config-volume
              readOnly: true
          dnsPolicy: Default
          restartPolicy: Always
          schedulerName: default-scheduler
          securityContext: {}
          serviceAccount: coredns
          serviceAccountName: coredns
          terminationGracePeriodSeconds: 30
          tolerations:
          - key: CriticalAddonsOnly
            operator: Exists
          - effect: NoSchedule
            key: node-role.kubernetes.io/master
          volumes:
          - configMap:
              defaultMode: 420
              items:
              - key: Corefile
                path: Corefile
              name: coredns
            name: config-volume
    
    ---
    apiVersion: v1
    kind: Service
    metadata:
      labels:
        k8s-app: kube-dns
        kubernetes.io/cluster-service: "true"
        kubernetes.io/name: KubeDNS
      name: kube-dns
      namespace: kube-system
    spec:
      selector:
        k8s-app: coredns
      clusterIP: 10.96.0.10
      ports:
      - name: dns
        port: 53
        protocol: UDP
        targetPort: 53
      - name: dns-tcp
        port: 53
        protocol: TCP
        targetPort: 53
      selector:
        k8s-app: kube-dns

等coredns的pod起来就恢复正常了