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

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 <<EOF
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  <none>  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 <<EOF
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.