k8s系列---Service之ExternalName用法
2024-08-31 17:56:47
需求：需要两个不同的namespace之间的不同pod可以通过name的形式访问
实现方式：
A:在其他pod内ping [svcname].[namespace] ping出来到结果就是svc的ip地址
B:通过externalname，把对方到[svcname].[namespace].svc.cluster.local，绑定到externalname定义到字符串上
1：创建A名称空间的pod
[root@k8s-m lihongxing]# cat myapp.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: myapp
namespace: cjy-test
spec:
replicas: 1
selector: #标签选择器
matchLabels: #匹配的标签为
app: myapp
release: canary
template:
metadata:
labels:
app: myapp #和上面的myapp要匹配
release: canary
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
ports:
- name: http
containerPort: 80
2：创建无头service，无头服务直接把请求解析到后端pod上，如果创建NodePort，ClusterIP那么后续验证就不要ping了，因为这个解析到是svc的IP，直接telnet加端口，或者curl 业务加端口验证
dig -t A myapp-svc.cjy-test.svc.cluster.local @172.16.132.10
[root@k8s-m lihongxing]# cat myapp-svc-headless.yaml
apiVersion: v1
kind: Service
metadata:
name: myapp-svc
namespace: cjy-test
spec:
selector:
app: myapp #挑选的pod还是myapp。一个pod可以有多个service
release: canary
clusterIP: None #None表示是无头service
ports:
- port: 39320 #service ip中的端口
targetPort: 80 #容器ip中的端口
3：创建ExternalName
[root@k8s-m lihongxing]# cat myapp-svc-extername.yaml
kind: Service
apiVersion: v1
metadata:
name: myapp-svcname
namespace: cjy-test
spec:
type: ExternalName
externalName: myapp-svc.cjy2-test.svc.cluster.local
在另一个名称空间的创建方式同上三步
两个名称空间都做完后，验证
[root@k8s-m ~]# kubectl get pods -n cjy-test
NAME READY STATUS RESTARTS AGE
myapp-deploy-f4db5d79c-zdgvv 1/1 Running 0 116m
myapp-f4db5d79c-xfs9l 1/1 Running 0 47m
[root@k8s-m ~]# kubectl exec -it myapp-f4db5d79c-xfs9l -n cjy-test -- /bin/sh
/ # nslookup myapp-svcname
nslookup: can't resolve '(null)': Name does not resolve Name: myapp-svcname
Address 1: 172.16.129.11 172-16-129-11.maypp.cjy2-test.svc.cluster.local
/ # ping myapp-svcname
PING myapp-svcname (172.16.129.11): 56 data bytes
64 bytes from 172.16.129.11: seq=0 ttl=64 time=0.534 ms
^C
--- myapp-svcname ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 0.534/0.534/0.534 ms / # nslookup myapp-svc.cjy2-test.svc.cluster.local
nslookup: can't resolve '(null)': Name does not resolve Name: myapp-svc.cjy2-test.svc.cluster.local
Address 1: 172.16.129.11 172-16-129-11.maypp.cjy2-test.svc.cluster.local / # exit
command terminated with exit code 127 [root@k8s-m ~]# kubectl get pods -n cjy2-test -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
myapp-f4db5d79c-6mpsm 1/1 Running 0 50m 172.16.129.11 k8s-w1.sai.corp <none> <none>
[root@k8s-m ~]# kubectl get svc -n cjy2-test -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
maypp ClusterIP 172.16.135.109 <none> 6381/TCP 101m app=myapp
myapp-svc ClusterIP None <none> 39321/TCP 55m app=myapp,release=canary
[root@k8s-m ~]# kubectl get svc -n cjy-test
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
maypp ClusterIP 172.16.134.116 <none> 6380/TCP 105m
myapp-svc ClusterIP None <none> 39320/TCP 69m
myapp-svcname ExternalName <none> myapp-svc.cjy2-test.svc.cluster.local <none> 62m
最新文章
- mysql中文乱码问题解决
- 实践中的Git常用指令分析
- [Jquery]焦点图轮播效果
- 【LeetCode OJ】Pascal's Triangle II
- ios项目记录
- VTL说明文档
- hdu 1754 I Hate It (模板线段树)
- htaccess 实现网址缩短
- ref与out之间的区别整理 摘自与望楼http://blog.csdn.net/xiaoning8201/article/details/6893154
- 蓝桥杯-平方怪圈-java
- visual studio错误中断处理
- 【django之stark组件】
- Ubuntu下安装GTK环境
- Android初级教程使用服务注册广播接收者监听手机解锁屏变化
- log4j日志文件名与行号显示乱码? 问号? 参数问号? 日志问号?【转】【补】
- Word 如何设置空白页不编码，其他页码连续
- hdu 1394(线段树) 最小逆序数
- JS - 兼容到ie7的自定义样式的滚动条封装
- imageNamed 、imageWithContentsOfFile、 initWithContentsFile区别
- linux下elasticsearch集成mongodb详细教程