问题：k8s启动的tomcat服务，每次访问都带了session会话，每次调整不同的pod导致session实效，系统登录失败。
处理：在server中添加session保持
sessionAffinity: ClientIP
实验：
启动服务：
[root@master test]# more Deploy.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: spring-k8s
spec:
replicas: 4
selector:
matchLabels:
app: spring-k8s
template:
metadata:
labels:
app: spring-k8s
spec:
containers:
- name: spring-k8s
image: jiangbo920827/spring-k8s:liveness
ports:
- containerPort: 8080
[root@master test]# more Service.yaml
apiVersion: v1
kind: Service
metadata:
name: spring-k8s
spec:
selector:
app: spring-k8s
type: NodePort
ports:
- nodePort: 30008
port: 80
protocol: TCP
targetPort: 8080
容器启动：
[root@master ~]# kubectl get pods |grep sprin spring-k8s-7db85b44fc-4d9xg 1/1 Running 0 1h spring-k8s-7db85b44fc-4rjp4 1/1 Running 0 1h spring-k8s-7db85b44fc-64v76 1/1 Running 0 1h spring-k8s-7db85b44fc-s5hhw 1/1 Running 0 1h
没加session亲和信参数：分布到各个pod
[root@master test]# for i in {1..10};do curl http://192.168.10.98:30008/hostname;echo ;done
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-4rjp4
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-64v76
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-s5hhw
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-64v76
spring-k8s-7db85b44fc-s5hhw
添加session亲和性参数：sessionAffinity: ClientIP
[root@master test]# more Service.yaml
apiVersion: v1
kind: Service
metadata:
name: spring-k8s
spec:
selector:
app: spring-k8s
type: NodePort
ports:
- nodePort: 30008
port: 80
protocol: TCP
targetPort: 8080
sessionAffinity: ClientIP
[root@master test]# for i in {1..10};do curl http://192.168.10.98:30008/hostname;echo ;done
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-4d9xg
spring-k8s-7db85b44fc-4d9xg