Kubernetes DNS Service installation configuration

Kubernetes's DNS service is implemented based on Skydns and requires close communication with API server, which works by creating an API server monitoring service and notifying Skydns to create a domain name resolution record once a new service is created. Communication between API server and Skydns is done by Kube2sky, both Kube2sky and Skydns need to implement shared configuration and service discovery using ETCD. The following is an architectural diagram of ETCD, which clearly illustrates
Kubernetes how to implement DNS.

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about Skydns and Kube2sky is installed in the local or pod installation into the k8s cluster, the author on the internet to see two ways, but the author of the local installation of the way to be skeptical, mainly related to virtual network and physical network connectivity issues, Specifically, the IP of the Skydns server should kube an IP address in the clustered virtual network, meaning that the IP needs to be within the specified IP address range of the Kube-apiserver boot parameter –service-cluster-ip-range. and Skydns If it is a localized installation, it is not possible to bind the IP of the DNS server to the IP of a virtual network (that is, the value of the parameter-addr). I would prefer to install it using mirroring mode.

Installation

The contents of the file Kubernetes-dns.yaml as follows:

apiversion: v1kind: replicationcontrollermetadata:  name: kube-dns-v6   namespace: default  labels:    k8s-app: kube-dns     version: v6    kubernetes.io/cluster-service:  "true" spec:   replicas: 1  selector:    k8s-app: kube-dns     version: v6  template:    metadata:       labels:        k8s-app: kube-dns         version: v6        kubernetes.io/ cluster-service:  "true"     spec:      containers:       - name: etcd        image:  index.tenxcloud.com/google_containers/etcd-amd64:2.2.1        command:         - /bin/etcd        - -listen-client-urls         - http://0.0.0.0:2379,http://0.0.0.0:4001         - -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:  index.tenxcloud.com/google_containers/kube2sky:1.14        resources:           limits:             cpu: 100m            memory: 50mi         livenssProbe:           httpget:            path: /healthz             port: 8080             scheme: HTTP           initialDelaySeconds: 60           timeoutseconds: 5          successthreshold:  1          failurethreshold: 5         readinessprobe:          httpget:             path: /readiness             port: 8081             scheme: http        initaldelayseconds: 30         timeoutseconds: 5      args :      - --domain=cluster.local      -  Name: skydns        image: index.tenxcloud.com/google_ containers/skydns:2015-10-13-8c72f8c        resources:         args:        - -machines=http://127.0.0.1:4001         - -addr=0.0.0.0:53        - - ns-rotate=false        - -domain=cluster.local.         ports:        - containerport:  53          name: dns           protocol: UDP        -  containerport: 53          name: dns-tcp           protocol: TCP       dnspolicy: default     - name: healthz        image: index.tenxcloud.com/google_containers/exechealthz:1.0       resources:          limits:             cpu: 100m            memory: 50mi        args:       - -cmd=nslookup  kubernetes.defaults.svc.cluster.local 127.0.0.1 >/dev/null        - -port=8080       ports:        - containerport: 8080         protocol:  tcp

use the following command: Kubectl create - F Kubernetes-dns.yaml

This article is from the "Network Technology exploration" blog, please be sure to keep this source http://heshengkai.blog.51cto.com/5014551/1946236

Kubernetes DNS Service installation configuration