018.Kubernetes二进制部署插件coredns

一 修改配置文件

1.1 下载解压

  1 [root@k8smaster01 ~]# cd /opt/k8s/work/kubernetes/
  2 [root@k8smaster01 kubernetes]# tar -xzvf kubernetes-src.tar.gz

提示：k8smaster01节点已解压完毕，可直接修改配置。

1.2 修改配置

  1 [root@k8smaster01 ~]# cd /opt/k8s/work/kubernetes/cluster/addons/dns/coredns
  2 [root@k8smaster01 coredns]# cp coredns.yaml.base coredns.yaml
  3 [root@k8smaster01 coredns]# source /opt/k8s/bin/environment.sh
  4 [root@k8smaster01 coredns]# sed -i -e "s/__PILLAR__DNS__DOMAIN__/${CLUSTER_DNS_DOMAIN}/" -e "s/__PILLAR__DNS__SERVER__/${CLUSTER_DNS_SVC_IP}/" coredns.yaml
  5 [root@k8smaster01 coredns]# vi coredns.yaml
  6 ……
  7         image: registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.3.1
  8 ……
  9 #修改image的源。

二 创建 coredns

2.1 创建coredns并检查

  1 [root@k8smaster01 coredns]# kubectl create -f coredns.yaml

2.2 检查 coredns 功能

  1 [root@k8smaster01 coredns]# kubectl get all -n kube-system

三 确认验证

3.1 新建Deployment

  1 [root@k8smaster01 ~]# cd /opt/k8s/work
  2 [root@k8smaster01 work]# cat > my-nginx.yaml <  3 apiVersion: extensions/v1beta1
  4 kind: Deployment
  5 metadata:
  6   name: my-nginx
  7 spec:
  8   replicas: 2
  9   template:
 10     metadata:
 11       labels:
 12         run: my-nginx
 13     spec:
 14       containers:
 15       - name: my-nginx
 16         image: nginx:1.7.9
 17         ports:
 18         - containerPort: 80
 19 EOF

3.2 export该Deployment

  1 [root@k8smaster01 work]# kubectl expose deploy my-nginx

3.3 查看该service

  1 [root@k8smaster01 work]# kubectl get services --all-namespaces | grep my-nginx
  2 default  my-nginx  ClusterIP  10.254.157.163    80/TCP  9s
  3 

3.4 创建另一个pod

  1 [root@k8smaster01 ~]# cd /opt/k8s/work
  2 [root@k8smaster01 work]# cat > dnsutils-ds.yml <  3 apiVersion: v1
  4 kind: Service
  5 metadata:
  6   name: dnsutils-ds
  7   labels:
  8     app: dnsutils-ds
  9 spec:
 10   type: NodePort
 11   selector:
 12     app: dnsutils-ds
 13   ports:
 14   - name: http
 15     port: 80
 16     targetPort: 80
 17 ---
 18 apiVersion: extensions/v1beta1
 19 kind: DaemonSet
 20 metadata:
 21   name: dnsutils-ds
 22   labels:
 23     addonmanager.kubernetes.io/mode: Reconcile
 24 spec:
 25   template:
 26     metadata:
 27       labels:
 28         app: dnsutils-ds
 29     spec:
 30       containers:
 31       - name: my-dnsutils
 32         image: tutum/dnsutils:latest
 33         command:
 34           - sleep
 35           - "3600"
 36         ports:
 37         - containerPort: 80
 38 EOF
 39 [root@k8smaster01 work]# kubectl create -f dnsutils-ds.yml
 40 [root@k8smaster01 work]# kubectl get pods -lapp=dnsutils-ds

3.5 检查解析

  1 [root@k8smaster01 ~]# kubectl create clusterrolebinding kube-apiserver:kubelet-apis --clusterrole=system:kubelet-api-admin --user kubernetes
  2 [root@k8smaster01 ~]# kubectl -it exec dnsutils-ds-4f2nt bash
  3 root@dnsutils-ds-4f2nt:/# cat /etc/resolv.conf
  4 nameserver 10.254.0.2
  5 search default.svc.cluster.local svc.cluster.local cluster.local
  6 options ndots:5
  7 
  8 [root@k8smaster01 work]# kubectl exec dnsutils-ds-4f2nt nslookup kubernetes
  9 [root@k8smaster01 work]# kubectl exec dnsutils-ds-4f2nt nslookup www.baidu.com
 10 [root@k8smaster01 work]# kubectl exec dnsutils-ds-4f2nt nslookup my-nginx
 11 [root@k8smaster01 work]# kubectl exec dnsutils-ds-4f2nt nslookup kube-dns.kube-system.svc
 12 [root@k8smaster01 work]# kubectl exec dnsutils-ds-4f2nt nslookup kube-dns.kube-system.svc.cluster.local
 13 [root@k8smaster01 work]# kubectl exec dnsutils-ds-4f2nt nslookup kube-dns.kube-system.svc.cluster.local.