Kubernetes1.15 部署 coredns

末蓝、 2021-11-01 06:34 276阅读 0赞

coredns.yaml文件如下所示

# __MACHINE_GENERATED_WARNING__
    
    apiVersion: v1
    kind: ServiceAccount
    metadata:
      name: coredns
      namespace: kube-system
      labels:
          kubernetes.io/cluster-service: "true"
          addonmanager.kubernetes.io/mode: Reconcile
    ---
    apiVersion: rbac.authorization.k8s.io/v1
    kind: ClusterRole
    metadata:
      labels:
        kubernetes.io/bootstrapping: rbac-defaults
        addonmanager.kubernetes.io/mode: Reconcile
      name: system:coredns
    rules:
    - apiGroups:
      - ""
      resources:
      - endpoints
      - services
      - pods
      - namespaces
      verbs:
      - list
      - watch
    - apiGroups:
      - ""
      resources:
      - nodes
      verbs:
      - get
    ---
    apiVersion: rbac.authorization.k8s.io/v1
    kind: ClusterRoleBinding
    metadata:
      annotations:
        rbac.authorization.kubernetes.io/autoupdate: "true"
      labels:
        kubernetes.io/bootstrapping: rbac-defaults
        addonmanager.kubernetes.io/mode: EnsureExists
      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
      labels:
          addonmanager.kubernetes.io/mode: EnsureExists
    data:
      Corefile: |
        .:53 {
            errors
            health
            kubernetes cluster.local in-addr.arpa ip6.arpa {
                pods insecure
                upstream
                fallthrough in-addr.arpa ip6.arpa
                ttl 30
            }
            prometheus :9153
            forward . /etc/resolv.conf
            cache 30
            loop
            reload
            loadbalance
        }
    ---
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: coredns
      namespace: kube-system
      labels:
        k8s-app: kube-dns
        kubernetes.io/cluster-service: "true"
        addonmanager.kubernetes.io/mode: Reconcile
        kubernetes.io/name: "CoreDNS"
    spec:
      # replicas: not specified here:
      # 1. In order to make Addon Manager do not reconcile this replicas parameter.
      # 2. Default is 1.
      # 3. Will be tuned in real time if DNS horizontal auto-scaling is turned on.
      strategy:
        type: RollingUpdate
        rollingUpdate:
          maxUnavailable: 1
      selector:
        matchLabels:
          k8s-app: kube-dns
      template:
        metadata:
          labels:
            k8s-app: kube-dns
          annotations:
            seccomp.security.alpha.kubernetes.io/pod: 'docker/default'
        spec:
          priorityClassName: system-cluster-critical
          serviceAccountName: coredns
          tolerations:
            - key: "CriticalAddonsOnly"
              operator: "Exists"
          nodeSelector:
            beta.kubernetes.io/os: linux
          containers:
          - name: coredns
            image: k8s.gcr.io/coredns:1.3.1
            imagePullPolicy: IfNotPresent
            resources:
              limits:
               memory: 70Mi
              requests:
                cpu: 100m
                memory: 70Mi
            args: [ "-conf", "/etc/coredns/Corefile" ]
            volumeMounts:
            - name: config-volume
              mountPath: /etc/coredns
              readOnly: true
            ports:
            - containerPort: 53
              name: dns
              protocol: UDP
            - containerPort: 53
              name: dns-tcp
              protocol: TCP
            - containerPort: 9153
              name: metrics
              protocol: TCP
            livenessProbe:
              httpGet:
                path: /health
                port: 8080
                scheme: HTTP
              initialDelaySeconds: 60
              timeoutSeconds: 5
              successThreshold: 1
              failureThreshold: 5
            readinessProbe:
              httpGet:
                path: /health
                port: 8080
                scheme: HTTP
            securityContext:
              allowPrivilegeEscalation: false
              capabilities:
                add:
                - NET_BIND_SERVICE
                drop:
                - all
              readOnlyRootFilesystem: true
          dnsPolicy: Default
          volumes:
            - name: config-volume
              configMap:
                name: coredns
                items:
                - key: Corefile
                  path: Corefile
    ---
    apiVersion: v1
    kind: Service
    metadata:
      name: kube-dns
      namespace: kube-system
      annotations:
        prometheus.io/port: "9153"
        prometheus.io/scrape: "true"
      labels:
        k8s-app: kube-dns
        kubernetes.io/cluster-service: "true"
        addonmanager.kubernetes.io/mode: Reconcile
        kubernetes.io/name: "CoreDNS"
    spec:
      selector:
        k8s-app: kube-dns
     clusterIP: 10.0.0.2
      ports:
      - name: dns
        port: 53
        protocol: UDP
      - name: dns-tcp
        port: 53
        protocol: TCP
      - name: metrics
        port: 9153
        protocol: TCP

修改以上yaml文件中红色部分修改成自己对于的信息

kubectl apply -f coredns.yaml

执行apply  生成pod（需要替换镜像，不然会拉取失败）

[root@k8s-master yaml]# kubectl get all -n kube-system | grep coredns
    pod/coredns-867ccfd476-9ghff              1/1     Running   13         42h
    pod/coredns-867ccfd476-p5md4              1/1     Running   15         42h
    deployment.apps/coredns                2/2     2            2           44h
    replicaset.apps/coredns-867ccfd476              2         2         2       44h
    [root@k8s-master yaml]#

创建测试的pod

[root@k8s-master test]# cat my-apache.yaml 
    apiVersion: extensions/v1beta1
    kind: Deployment
    metadata:
      name: my-apache
    spec:
      replicas: 2
      template:
        metadata:
          labels:
            run: my-apache
        spec:
          containers:
          - name: my-apache
            image: httpd:2.4
            ports:
            - containerPort: 80
    
    ---
    apiVersion: v1
    kind: Service
    metadata:
      name: my-apache
      labels:
        run: my-apache
    spec:
      type: NodePort
      ports:
      - port: 80
        targetPort: 80
        nodePort: 30002
      selector:
        run: my-apache

生成pod

[root@k8s-master test]# kubectl apply -f my-apache.yaml

查看pod运行状态

[root@k8s-master test]# kubectl get pod 
    NAME                         READY   STATUS    RESTARTS   AGE
    my-apache-75f574f468-8psfw   1/1     Running   1          24h
    my-apache-75f574f468-msrrn   1/1     Running   0          24h
    [root@k8s-master test]#

已经全部运行

[root@k8s-master test]# kubectl get svc 
    NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)        AGE
    kubernetes   ClusterIP   10.0.0.1     <none>        443/TCP        2d
    my-apache    NodePort    10.0.0.71    <none>        80:30002/TCP   24h
    [root@k8s-master test]# curl 10.0.0.71
    <html><body><h1>It works!</h1></body></html>
    [root@k8s-master test]#

由此可见dns服务是可用的

转载于:https://www.cnblogs.com/daydev/p/11202323.html