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This article introduces the relevant knowledge of "how to deploy coredns in K8s". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Why do I need DNS?

Usually, service discovery in k8s cluster is implemented through dns, which can be implemented using kubedns or coredns.

The namespace specified by DNS is usually kube-system. When viewing, you need to specify namespace to view.

Edit the coredns yaml file

# cat coredns.yaml 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 health kubernetes cluster.local. In-addr.arpa ip6.arpa {pods insecure upstream fallthrough in-addr.arpa ip6.arpa} prometheus: 9153 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: 2 strategy: type: RollingUpdate rollingUpdate: maxUnavailable: 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: coredns/coredns:1.0.6 imagePullPolicy: IfNotPresent resources: limits: Memory: 170Mi requests: cpu: 100m memory: 70Mi args: ["- conf" VolumeMounts:-name: config-volume mountPath: / etc/coredns ports:-containerPort: 53 name: dns protocol: UDP-containerPort: 53 name: dns-tcp 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: 10.1.0.2 ports:-name: dns port: 53 protocol: UDP-name: dns-tcp port: 53 protocol: TCP

Create deployment

Kubectl create-f coredns.yaml

View relevant information

Kubectl get svc-n kube-systemkubectl get pod-o wide-n kube-system

Note that the cluster IP specified in the creation coredns deployment yaml file is specified according to the K8s cluster plan.

This is the end of "how to deploy coredns in K8s". Thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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