DNS部署

基于上一篇文章从零开始搭建基于calico的kubenetes，已经完成了kubernetes的部署。但未 部署DNS。本章节将介绍DNS部署。

配置文件准备

skydns-rc.yaml 注意此文件与kubernetes官方提供的模板相比，在此mount了从节点的配置文件/etc/kubernetes/worker-kubeconfig.yaml,原因在于DNS部署有时候会出现很多未知的错误，如：10.100.0.1:443链接被拒绝、或者证书加载错误等:

# Copyright 2016 The Kubernetes Authors. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # TODO - At some point, we need to rename all skydns-*.yaml.* files to kubedns-*.yaml.* # Warning: This is a file generated from the base underscore template file: skydns-rc.yaml.base 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: shenshouer/kubedns-amd64:1.9 resources: # TODO: Set memory limits when we've profiled the container for large # clusters, then set request = limit to keep this container in # guaranteed class. Currently, this container falls into the # "burstable" category so the kubelet doesn't backoff from restarting it. 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 # we poll on pod startup for the Kubernetes master service and # only setup the /readiness HTTP server once that's available. initialDelaySeconds: 3 timeoutSeconds: 5 args: # command = "/kube-dns" - --domain=cluster.local. - --dns-port=10053 # - --kube-master-url=https://172.18.8.101 - --kubecfg-file=/etc/kubernetes/worker-kubeconfig.yaml - --federations=myfederation=federation.test ports: - containerPort: 10053 name: dns-local protocol: UDP - containerPort: 10053 name: dns-tcp-local protocol: TCP volumeMounts: - mountPath: /etc/ssl/certs name: "ssl-certs" - mountPath: /etc/kubernetes/worker-kubeconfig.yaml name: "kubeconfig" readOnly: true - mountPath: /etc/kubernetes/ssl name: "etc-kube-ssl" readOnly: true - name: dnsmasq image: shenshouer/kube-dnsmasq-amd64:1.4 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: shenshouer/exechealthz-amd64:1.2 resources: limits: memory: 50Mi requests: cpu: 10m # Note that this container shouldn't really need 50Mi of memory. The # limits are set higher than expected pending investigation on #29688. # The extra memory was stolen from the kubedns container to keep the # net memory requested by the pod constant. 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 # Don't use cluster DNS. volumes: - name: "ssl-certs" hostPath: path: "/usr/share/ca-certificates" - name: "kubeconfig" hostPath: path: "/etc/kubernetes/worker-kubeconfig.yaml" - name: "etc-kube-ssl" hostPath: path: "/etc/kubernetes/ssl"

skydns-svc.yaml与官方模板相同:

# Copyright 2016 The Kubernetes Authors. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # TODO - At some point, we need to rename all skydns-*.yaml.* files to kubedns-*.yaml.* # Warning: This is a file generated from the base underscore template file: skydns-svc.yaml.base 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: 172.30.0.10 ports: - name: dns port: 53 protocol: UDP - name: dns-tcp port: 53 protocol: TCP

http://blog.csdn.net/shenshouer/article/details/52946194?locationNum=2&fps=1

http://blog.csdn.net/shenshouer/article/details/53035948

https://github.com/kubernetes/kubernetes/tree/master/cluster/addons/dns

本文转自开源中国-k8s dns 带证书配置