为了是集群内的服务能使用dns进行服务解析，集群内需要使用dns服务器，可以按照kube官方dns，即kubedns或者其他的dns，比如coredns，
本例中按照的为coredns，按照简单，编辑文件执行create部署即可，使用现成的镜像安装。
在/etc/kubernetes/yamlfile新增配置文件coredns.yaml,当然这个文件你随意放置，我只是归类而已，安装节点为master节点，node无需安装
1、预先下载corends的镜像
docker pull registry.docker-cn.com/coredns/coredns:0.9.10
2、新增配置文件coredns.yaml配置文件内容：
注意配置文件中红色指定的image在本地仓库一定要存在，按照第一步下载下来接口，且名称要对应上
apiVersion: v1kind: ServiceAccountmetadata: ?name: coredns ?namespace: kube-system ?labels: ?????kubernetes.io/cluster-service: "true" ?????addonmanager.kubernetes.io/mode: Reconcile---apiVersion: rbac.authorization.k8s.io/v1kind: ClusterRolemetadata: ?labels: ???kubernetes.io/bootstrapping: rbac-defaults ???addonmanager.kubernetes.io/mode: Reconcile ?name: system:corednsrules:- apiGroups: ?- "" ?resources: ?- endpoints ?- services ?- pods ?- namespaces ?verbs: ?- list ?- watch---apiVersion: rbac.authorization.k8s.io/v1kind: ClusterRoleBindingmetadata: ?annotations: ???rbac.authorization.kubernetes.io/autoupdate: "true" ?labels: ???kubernetes.io/bootstrapping: rbac-defaults ???addonmanager.kubernetes.io/mode: EnsureExists ?name: system:corednsroleRef: ?apiGroup: rbac.authorization.k8s.io ?kind: ClusterRole ?name: system:corednssubjects:- kind: ServiceAccount ?name: coredns ?namespace: kube-system---apiVersion: v1kind: ConfigMapmetadata: ?name: coredns ?namespace: kube-system ?labels: ?????addonmanager.kubernetes.io/mode: EnsureExistsdata: ?Corefile: | ???.:53 { ???????errors ???????log stdout ???????health ???????kubernetes cluster.local 10.254.0.0/16 ???????prometheus ???????proxy . /etc/resolv.conf ???????cache 30 ???}---apiVersion: extensions/v1beta1kind: Deploymentmetadata: ?name: coredns ?namespace: kube-system ?labels: ???k8s-app: coredns ???kubernetes.io/cluster-service: "true" ???addonmanager.kubernetes.io/mode: Reconcile ???kubernetes.io/name: "CoreDNS"spec: ?replicas: 1 ?selector: ???matchLabels: ?????k8s-app: coredns ?template: ???metadata: ?????labels: ???????k8s-app: coredns ???spec: ?????serviceAccountName: coredns ?????tolerations: ???????- key: node-role.kubernetes.io/master ?????????effect: NoSchedule ???????- key: "CriticalAddonsOnly" ?????????operator: "Exists" ?????containers: ?????- name: coredns ???????image: registry.docker-cn.com/coredns/coredns:0.9.10 ???????imagePullPolicy: IfNotPresent ???????resources: ?????????limits: ???????????memory: 170Mi ?????????requests: ???????????cpu: 100m ???????????memory: 70Mi ???????args: [ "-conf", "/etc/coredns/Corefile" ] ???????volumeMounts: ???????- name: config-volume ?????????mountPath: /etc/coredns ???????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 ?????dnsPolicy: Default ?????volumes: ???????- name: config-volume ?????????configMap: ???????????name: coredns ???????????items: ???????????- key: Corefile ?????????????path: Corefile---apiVersion: v1kind: Servicemetadata: ?name: coredns ?namespace: kube-system ?labels: ???k8s-app: coredns ???kubernetes.io/cluster-service: "true" ???addonmanager.kubernetes.io/mode: Reconcile ???kubernetes.io/name: "CoreDNS"spec: ?selector: ???k8s-app: coredns ?clusterIP: 10.254.0.2 ?ports: ?- name: dns ???port: 53 ???protocol: UDP ?- name: dns-tcp ???port: 53 ???protocol: TCP ?- name: metrics ???port: 9153 ???protocol: TCP3、部署coredns
kubectl create -f coredns.yaml
执行完成后开始添加服务及启动，可以通过kubectl cluster-info查看
以及
kubectl get services coredns -n kube-system
Kubernetes1.91（K8s）安装部署过程（七）--coredns安装
原文地址：https://www.cnblogs.com/netsa/p/8376438.html