kubernetes部署-Kubernetes DNS(九)

字数 7090阅读 1190评论 0赞 1

#  kubernetes部署-Kubernetes DNS 
 ## 部署-Kubernetes DNS

创建DNS 用来自动对应主机和集群IP

## 直接创建yaml文件来创建dns
```
apiVersion: v1  
kind: Service  
metadata:  
name: kube-dns  
namespace: kube-system  
labels:  
k8s-app: kube-dns  
kubernetes.io/cluster-service: "true"  
addonmanager.kubernetes.io/mode: Reconcile  
kubernetes.io/name: "KubeDNS"  
spec:  
selector:  
k8s-app: kube-dns  
clusterIP: 10.0.0.2 #我们指定一个dns地址空的没用的ip,这个地址其实在node1,2的kubelet.config里有指定  
ports:  
- name: dns  
port: 53  
protocol: UDP  
- name: dns-tcp  
port: 53  
protocol: TCP  
---  
apiVersion: v1  
kind: ServiceAccount  
metadata:  
name: kube-dns  
namespace: kube-system  
labels:  
kubernetes.io/cluster-service: "true"  
addonmanager.kubernetes.io/mode: Reconcile  
---  
apiVersion: v1  
kind: ConfigMap  
metadata:  
name: kube-dns  
namespace: kube-system  
labels:  
addonmanager.kubernetes.io/mode: EnsureExists  
---  
apiVersion: extensions/v1beta1  
kind: Deployment  
metadata:  
name: kube-dns  
namespace: kube-system  
labels:  
k8s-app: kube-dns  
kubernetes.io/cluster-service: "true"  
addonmanager.kubernetes.io/mode: Reconcile  
spec:  
# replicas: not specified here:  
# 1. In order to make Addon Manager do not reconcile this replicas parameter.  
# 2. Default is 1.  
# 3. Will be tuned in real time if DNS horizontal auto-scaling is turned on.  
strategy:  
rollingUpdate:  
maxSurge: 10%  
maxUnavailable: 0  
selector:  
matchLabels:  
k8s-app: kube-dns  
template:  
metadata:  
labels:  
k8s-app: kube-dns  
annotations:  
scheduler.alpha.kubernetes.io/critical-pod: ''  
spec:  
tolerations:  
- key: "CriticalAddonsOnly"  
operator: "Exists"  
volumes:  
- name: kube-dns-config  
configMap:  
name: kube-dns  
optional: true  
containers:  
- name: kubedns  
image: registry.cn-hangzhou.aliyuncs.com/google_containers/k8s-dns-kube-dns-amd64:1.14.7  
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: /healthcheck/kubedns  
port: 10054  
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:  
- --domain=cluster.local. # 这个名字是之前创建证书里创建的  
- --dns-port=10053  
- --config-dir=/kube-dns-config  
- --v=2  
env:  
- name: PROMETHEUS_PORT  
value: "10055"  
ports:  
- containerPort: 10053  
name: dns-local  
protocol: UDP  
- containerPort: 10053  
name: dns-tcp-local  
protocol: TCP  
- containerPort: 10055  
name: metrics  
protocol: TCP  
volumeMounts:  
- name: kube-dns-config  
mountPath: /kube-dns-config  
- name: dnsmasq  
image: registry.cn-hangzhou.aliyuncs.com/google_containers/k8s-dns-dnsmasq-nanny-amd64:1.14.7  
livenessProbe:  
httpGet:  
path: /healthcheck/dnsmasq  
port: 10054  
scheme: HTTP  
initialDelaySeconds: 60  
timeoutSeconds: 5  
successThreshold: 1  
failureThreshold: 5  
args:  
- -v=2  
- -logtostderr  
- -configDir=/etc/k8s/dns/dnsmasq-nanny  
- -restartDnsmasq=true  
- --  
- -k  
- --cache-size=1000  
- --no-negcache  
- --log-facility=-  
- --server=/cluster.local/127.0.0.1#10053  
- --server=/in-addr.arpa/127.0.0.1#10053  
- --server=/ip6.arpa/127.0.0.1#10053  
ports:  
- containerPort: 53  
name: dns  
protocol: UDP  
- containerPort: 53  
name: dns-tcp  
protocol: TCP  
# see: https://github.com/kubernetes/kubernetes/issues/29055 for details  
resources:  
requests:  
cpu: 150m  
memory: 20Mi  
volumeMounts:  
- name: kube-dns-config  
mountPath: /etc/k8s/dns/dnsmasq-nanny  
- name: sidecar  
image: registry.cn-hangzhou.aliyuncs.com/google_containers/k8s-dns-sidecar-amd64:1.14.7  
livenessProbe:  
httpGet:  
path: /metrics  
port: 10054  
scheme: HTTP  
initialDelaySeconds: 60  
timeoutSeconds: 5  
successThreshold: 1  
failureThreshold: 5  
args:  
- --v=2  
- --logtostderr  
- --probe=kubedns,127.0.0.1:10053,kubernetes.default.svc.cluster.local,5,SRV  
- --probe=dnsmasq,127.0.0.1:53,kubernetes.default.svc.cluster.local,5,SRV  
ports:  
- containerPort: 10054  
name: metrics  
protocol: TCP  
resources:  
requests:  
memory: 20Mi  
cpu: 10m  
dnsPolicy: Default # Don't use cluster DNS.  
serviceAccountName: kube-dns

```
kubectl apply -f kube-dns.yaml

## 查看一下pod是否已经正常运行

```
[root@node dns]# kubectl apply -f kube-dns.yaml ^C  
[root@node dns]# kubectl get pod -o wide -n kube-system  
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GAT  
ESheapster-c679b85f9-bldkw 1/1 Running 0 27m 172.17.71.6 10.167.130.206    
kube-dns-5c74856c48-j44h4 3/3 Running 0 51m 172.17.71.8 10.167.130.206    
kubernetes-dashboard-7b79f98f97-wxkkc 1/1 Running 0 5d19h 172.17.71.4 10.167.130.206    
monitoring-grafana-76bd45d446-8v6bb 1/1 Running 0 27m 172.17.71.5 10.167.130.206    
monitoring-influxdb-84f8f76d94-76ffj 1/1 Running 0 27m 172.17.71.7 10.167.130.206    
```
可以看到kube-dns已经Running了

## 创建新的pod进行dns的验证看是否正常

```
cd /home/dns

cat > my-nginx.yaml<<EOF
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: my-nginx   #最终会显示到svc中,与集群IP对应关系
spec:
  replicas: 2
  template:
    metadata:
      labels:
        run: my-nginx
    spec:
      containers:
      - name: my-nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80
EOF

kubectl create -f my-nginx.yaml
deployment "my-nginx" created

```
Expose 该Deployment，生成my-nginx 服务  
```
kubectl expose deploy my-nginx  
  
[root@k8s-master01 pod]# kubectl get svc  
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE  
kubernetes ClusterIP 10.0.0.1  443/TCP 11d  
my-nginx ClusterIP 10.0.0.157  80/TCP 51m  
nginx NodePort 10.0.0.116  88:31961/TCP 10d  
tomcat LoadBalancer 10.0.0.16  8080:32934/TCP 6d19h  
```
然后创建另外一个Pod，查看/etc/resolv.conf是否包含kubelet配置的–cluster-dns 和–cluster-domain，是否能够将服务my-nginx 解析到上面显示的CLUSTER-IP 10.0.0.157 上  
```
cat > pod-nginx.yaml<<EOF
apiVersion: v1
kind: Pod
metadata:
  name: podnginx
spec:
  containers:
  - name: nginx
    image: nginx:1.7.9
    ports:
    - containerPort: 80
EOF

kubectl create -f pod-nginx.yaml
pod "podnginx" created

kubectl exec  podnginx -i -t /bin/bash   #终端交互进入podnginx容器内
查看一下/etc/resolv.conf  看是否是我们创建的dns地址10.0.0.2

[root@node dns]# kubectl exec podnginx -it /bin/bash
root@podnginx:/# cat /etc/resolv.conf 
nameserver 10.0.0.2
search default.svc.cluster.local. svc.cluster.local. cluster.local.
options ndots:5

尝试ping一下我们之前创建的my-nginx
root@podnginx:/# ping my-nginx
PING my-nginx.default.svc.cluster.local (10.0.0.157): 48 data bytes   #正确解析到了集群IP,ping是不通的,但是可以解析到就OK

```

kubernetes部署 Kubernetes

著作权归作者所有

如果觉得我的文章对您有用，请点赞。您的支持将鼓励我继续创作！

添加新评论0 条评论

Ctrl+Enter 发表

匿名评论

kubernetes部署-Kubernetes DNS(九)

添加新评论0 条评论

作者其他文章

相关文章

相关问题

相关资料