八.kubernetes dns 部署

[在minion节点]

修改启动服务的参数

vim start_k8s_minion.sh

#添加
dns_ip="172.100.10.1"

#增加--cluster-dns  --cluster-domain
nohup kubelet --address=0.0.0.0 --port=10250 --v=1 --log_dir=/var/log/k8s/kubelet --hostname_override=$local_ip --api_servers=http://$master_ip:8080 --cluster-dns=$dns_ip --cluster-domain=cluster.local. --logtostderr=false &

重启服务

./start_k8s_minion.sh

下载相关镜像，由于国外镜像被墙，所以下载国内第三方镜像

docker pull chasontang/kubedns-amd64:1.7
docker pull chasontang/kube-dnsmasq-amd64:1.3
docker pull chasontang/exechealthz-amd64:1.1

给镜像打标签

docker tag chasontang/kubedns-amd64:1.7 gcr.io/google_containers/kubedns-amd64:1.7
docker tag chasontang/kube-dnsmasq-amd64:1.3 gcr.io/google_containers/kube-dnsmasq-amd64:1.3
docker tag  chasontang/exechealthz-amd64:1.1 gcr.io/google_containers/exechealthz-amd64:1.1

[在master节点]

准备dns的yaml文件

dns yaml文件位置： /root/kubernetes/cluster/addons/dns
文件名称：
skydns-rc.yaml.in
skydns-svc.yaml.in

cd /root/kubernetes/cluster/addons/dns
cp skydns-rc.yaml.in skydns-svc.yaml.in /root/
cd /root/
mv skydns-rc.yaml.in skydns-rc.yaml
mv skydns-svc.yaml.in skydns-svc.yaml

编辑dns的yaml文件

vim skydns-rc.yaml

replicas: {{ pillar['dns_replicas'] }}  
修改为  
replicas: 1

args:
# command = "/kube-dns"
- --domain={{ pillar['dns_domain'] }}.
- --dns-port=10053
{{ pillar['federations_domain_map'] }}

修改为

args:
# command = "/kube-dns"
- --domain=cluster.local.
- --dns-port=10053
- --kube-master-url=http://10.2.1.11:8080

- -cmd=nslookup kubernetes.default.svc.{{ pillar['dns_domain'] }} 127.0.0.1 >/dev/null && nslookup kubernetes.default.svc.{{ pillar['dns_domain'] }} 127.0.0.1:10053 >/dev/null

修改为

- -cmd=nslookup kubernetes.default.svc.cluster.local. 127.0.0.1 >/dev/null && nslookup kubernetes.default.svc.cluster.local. 127.0.0.1:10053 >/dev/null

vim skydns-svc.yaml

clusterIP: {{ pillar['dns_server'] }}

修改为

clusterIP: 172.100.10.1

启动rc与svc

kubectl create -f skydns-rc.yaml
kubectl create -f skydns-svc.yaml

测试

vim test.yaml

apiVersion: v1
kind: ReplicationController
metadata:
  name: test
  namespace: kube-system
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: test
    spec:
      containers:
      - name: test
        image: 10.2.3.223:5000/base:v1.2.1_autoserver
        ports:
        - containerPort: 80
          protocol: TCP
        volumeMounts:
        - mountPath: /work
          name: test-volume
      volumes:
        - name: test-volume
          hostPath:
            path: /work/test
---
kind: Service
apiVersion: v1
metadata:
  labels:
    app: test
  name: test
  namespace: kube-system
spec:
  type: NodePort
  ports:
  - port: 80
    targetPort: 30080
  selector:
    app: test

启动

kubectl create -f test.yaml

测试，登陆的刚刚启动容器

ssh 172.100.35.3

查看DNS

cat /etc/resolv.conf 
search kube-system.svc.cluster.local. svc.cluster.local. cluster.local.
nameserver 172.100.10.1
options ndots:5

ping test
PING test.kube-system.svc.cluster.local (172.100.252.152) 56(84) bytes of data.

可以解析，成功

参考资料

• https://my.oschina.net/fufangchun/blog/732762
• http://ju.outofmemory.cn/entry/285913
• http://weixinrensheng.com/v4bfMDLY/
• http://blog.csdn.net/carter115/article/details/51133688
• http://www.cnblogs.com/openxxs/p/5015734.html