k8s dns 服务安装配置说明

1. 提前条件

安装k8s 集群

2.  dns  安装配置

安装方式: 使用controller  service

controller  脚本：

基于官方改动

apiVersion: v1
kind: ReplicationController
metadata:
  name: kube-dns-v8
  namespace: kube-system
  labels:
    k8s-app: kube-dns
    version: v8
    kubernetes.io/cluster-service: "true"
spec:
  replicas: 1
  selector:
    k8s-app: kube-dns
    version: v8
  template:
    metadata:
      labels:
        k8s-app: kube-dns
        version: v8
        kubernetes.io/cluster-service: "true"
    spec:
      containers:
      - name: etcd
        image: tlitiwwhtmi/etcd
        resources:
          limits:
            cpu: 100m
            memory: 50Mi
        command:
        - /usr/local/bin/etcd
        - -data-dir
        - /var/etcd/data
        - -listen-client-urls
        - http://127.0.0.1:2379,http://127.0.0.1:4001
        - -advertise-client-urls
        - http://127.0.0.1:2379,http://127.0.0.1:4001
        - -initial-cluster-token
        - skydns-etcd
        volumeMounts:
        - name: etcd-storage
          mountPath: /var/etcd/data
      - name: kube2sky
        image: outrider/kube2sky
        resources:
          limits:
            cpu: 100m
            memory: 50Mi
        args:
        # command = "/kube2sky"
        - --domain=cluster.local
        - --kube_master_url=http://10.25.143.50:8080
      - name: skydns
        image: outrider/skydns
        resources:
          limits:
            cpu: 100m
            memory: 50Mi
        args:
        # command = "/skydns"
        - -machines=http://localhost:4001
        - -addr=0.0.0.0:53
        - -domain=cluster.local
        ports:
        - containerPort: 53
          name: dns
          protocol: UDP
        - containerPort: 53
          name: dns-tcp
          protocol: TCP
        livenessProbe:
          httpGet:
            path: /healthz
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 30
          timeoutSeconds: 5
      - name: healthz
        image: outrider/exechealthz
        resources:
          limits:
            cpu: 10m
            memory: 20Mi
        args:
        - -cmd=nslookup kubernetes.default.svc.cluster.local localhost >/dev/null
        - -port=8080
        ports:
        - containerPort: 8080
          protocol: TCP
      volumes:
      - name: etcd-storage
        emptyDir: {}
      dnsPolicy: Default  # Don‘t use cluster DNS.

service

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: 10.254.0.3
  ports:
  - name: dns
    port: 53
    protocol: UDP
  - name: dns-tcp
    port: 53
    protocol: TCP

　　创建namespace

apiVersion: v1
kind: Namespace
metadata:
  name: kube-system

3. node  进行 dns 配置

在启动脚本添加：

 --cluster-dns=10.254.0.3  --cluster-domain=cluster.local

4. 重启node

5. 测试pod

apiVersion: v1
kind: Pod
metadata:
  name: busybox
  namespace: default
spec:
  containers:
  - image: busybox
    command:
      - sleep
      - "3600"
    imagePullPolicy: IfNotPresent
    name: busybox
  restartPolicy: Always

6. 测试

kubectl  exec busybox -- nslookup ngservice

　测试结果

Server:    10.254.0.3
Address 1: 10.254.0.3

Name:      ngservice
Address 1: 10.254.52.109