kubernetes dashboard kube-dns

             当搭建完kubernetes后，我们需要使用一个UI平台来对集群进行操作服务, kubernetes 自身就有 dashboard功能
 
               dashboard yaml 如下:
              

[root@kuber-master-141 kube-yaml]# cat kubernetes-dashboard.yaml 

kind: Deployment
apiVersion: extensions/v1beta1
metadata:
  labels:
    app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: kubernetes-dashboard
  template:
    metadata:
      labels:
        app: kubernetes-dashboard
      # Comment the following annotaion if Dashboard must not be deployed on master
      annotations:
        scheduler.alpha.kubernetes.io/tolerations: |
          [
            {
              "key": "dedicated",
              "operator": "Equal",
              "value": "master",
              "effect": "NoSchedule"
            }
          ]
    spec:
      containers:
      - name: kubernetes-dashboard
        image: docker.io/zhouyan/kubernetes-dashboard-amd64:v1.4.2  // docker hub 拉取相应景象
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9090
          protocol: TCP
        args:
          # Uncomment the following line to manually specify Kubernetes API server Host
          # If not specified, Dashboard will attempt to auto discover the API server and connect
          # to it. Uncomment only if the default does not work.
          - --apiserver-host=  // 填写自身的apiserver地址端口
        livenessProbe:
          httpGet:
            path: /
            port: 9090
          initialDelaySeconds: 30
          timeoutSeconds: 30
---
kind: Service
apiVersion: v1
metadata:
  labels:
    app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  type: NodePort
  ports:
  - port: 80
    targetPort: 9090
  selector:
    app: kubernetes-dashboard

                  然后通过 master_ip:端口/ui 访问 dashboard, 如本例就是 10.3.1.141:8080/ui


    

                dashboard中也可以看到, po sv 的yaml, 通过edit进行版本更新

               下面我们来介绍一个kube-dns,老版本的kubernetes安装的是 sky-dns，之后kubernetes也推出了自己的dns套件，kube-dns
               简单介绍下kube-dns的套件，以及相应功能。

               kube-dns:  list/watch k8s service api接口
                kube-dnsmasq: 给pod提供DNS解析，并使用自身的DNS缓存功能
               exechealthz： 检测上述2个服务的健康状态

               kube-dns.yml
               

apiVersion: v1
kind: Service
metadata:
  name: kube-dns
  namespace: kube-system
  labels:
    k8s-app: kube-dns
    kubernetes.io/cluster-service: "true"
    kubernetes.io/name: "KubeDNS"
spec:
  selector:
    k8s-app: kube-dns
  clusterIP: 20.254.176.10 // 根据自己的IP段，设置kube-dns 静态IP
  ports:
  - name: dns
    port: 53
    protocol: UDP
  - name: dns-tcp
    port: 53
    protocol: TCP




---




apiVersion: v1
kind: ReplicationController
metadata:
  name: kube-dns-v20
  namespace: kube-system
  labels:
    k8s-app: kube-dns
    version: v20
    kubernetes.io/cluster-service: "true"
spec:
  replicas: 1
  selector:
    k8s-app: kube-dns
    version: v20
  template:
    metadata:
      labels:
        k8s-app: kube-dns
        version: v20
      annotations:
        scheduler.alpha.kubernetes.io/critical-pod: ''
        scheduler.alpha.kubernetes.io/tolerations: '[{"key":"CriticalAddonsOnly", "operator":"Exists"}]'
    spec:
      containers:
      - name: kubedns
        image: docker.io/swqmaven/kubedns-amd64:1.8
        imagePullPolicy: IfNotPresent
        resources:
          limits:
            memory: 170Mi
          requests:
            cpu: 100m
            memory: 70Mi
        livenessProbe:
          httpGet:
            path: /healthz-kubedns
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 60
          timeoutSeconds: 5
          successThreshold: 1
          failureThreshold: 5
        readinessProbe:
          httpGet:
            path: /readiness
            port: 8081
            scheme: HTTP
          initialDelaySeconds: 5
          timeoutSeconds: 5
        args:
        - --domain=cluster.local.
        - --dns-port=10053
        - --kube_master_url= // 根据自身的apiservice地址填写
        ports:
        - containerPort: 10053
          name: dns-local
          protocol: UDP
        - containerPort: 10053
          name: dns-tcp-local
          protocol: TCP
      - name: dnsmasq
        image: docker.io/swqmaven/kube-dnsmasq-amd64:1.4
        imagePullPolicy: IfNotPresent
        livenessProbe:
          httpGet:
            path: /healthz-dnsmasq
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 60
          timeoutSeconds: 5
          successThreshold: 1
          failureThreshold: 5
        args:
        - --cache-size=1000
        - --no-resolv
        - --server=127.0.0.1#10053
        - --log-facility=-
        ports:
        - containerPort: 53
          name: dns
          protocol: UDP
        - containerPort: 53
          name: dns-tcp
          protocol: TCP
      - name: healthz
        image: docker.io/swqmaven/exechealthz-amd64:1.2
        imagePullPolicy: IfNotPresent
        resources:
          limits:
            memory: 50Mi
          requests:
            cpu: 10m
            memory: 50Mi
        args:
        - --cmd=nslookup kubernetes.default.svc.cluster.local 127.0.0.1 >/dev/null
        - --url=/healthz-dnsmasq
        - --cmd=nslookup kubernetes.default.svc.cluster.local 127.0.0.1:10053 >/dev/null
        - --url=/healthz-kubedns
        - --port=8080
        - --quiet
        ports:
        - containerPort: 8080
          protocol: TCP
      dnsPolicy: Default

        配置kubelet文件，添加dns设置
        [root@kuber-minion-131 data]# grep "ARGS" /etc/kubernetes/kubelet 
        KUBELET_ARGS="--cluster_dns=20.254.176.10 --cluster_domain=cluster.local"
        重启 kubelet.service

        systemctl restart kubelet.service

       新建一个busybox 测试DNS功能
       [root@kuber-minion-131 data]# kubectl get svc --all-namespaces 
        NAMESPACE     NAME                   CLUSTER-IP       EXTERNAL-IP   PORT(S)         AGE
        default       kubernetes             20.254.0.1              443/TCP         31d
        kube-system   kube-dns               20.254.176.10            53/UDP,53/TCP   24d
        kube-system   kubernetes-dashboard   20.254.176.225   nodes         80/TCP          27d

        [root@kuber-minion-131 data]# kubectl exec busybox -- nslookup kube-dns.kube-system
        Server:    20.254.176.10
        Address 1: 20.254.176.10 kube-dns.kube-system.svc.cluster.local

        Name:      kube-dns.kube-system
        Address 1: 20.254.176.10 kube-dns.kube-system.svc.cluster.local

        [root@kuber-minion-131 data]# kubectl exec busybox -- nslookup kubernetes
        Server:    20.254.176.10
        Address 1: 20.254.176.10 kube-dns.kube-system.svc.cluster.local

        Name:      kubernetes
        Address 1: 20.254.0.1 kubernetes.default.svc.cluster.local

       OK, 今天我们要做的2件事都完成了，dashboard与dns部署, 散会.


                          
                                                                                        Cail_wepiao

     
       参考链接：