service session sticky
kind: Service
apiVersion: v1
metadata:name: my-service
spec:selector:app: my-appports:- name: httpprotocol: TCPport: 80targetPort: 80sessionAffinity: ClientIPsessionAffinityConfig:clientIP:timeoutSeconds: 10
ingress
- 问题:为什么在ingress中不能使用上面service的session sticky。
- 答案:因为ingress controller中配置的是POD的地址，不经过service，所以上面的service方式不生效。
Nginx Controller
https://kubernetes.github.io/ingress-nginx/examples/affinity/cookie/
Session affinity can be configured using the following annotations:
| Name | Description | Value |
|---|---|---|
| nginx.ingress.kubernetes.io/affinity | Type of the affinity, set this to cookie to enable session affinity | string (NGINX only supports cookie) |
| nginx.ingress.kubernetes.io/affinity-mode | The affinity mode defines how sticky a session is. Use balanced to redistribute some sessions when scaling pods or persistent for maximum stickyness. | balanced (default) or persistent |
| nginx.ingress.kubernetes.io/session-cookie-name | Name of the cookie that will be created | string (defaults to INGRESSCOOKIE) |
| nginx.ingress.kubernetes.io/session-cookie-path | Path that will be set on the cookie (required if your Ingress paths use regular expressions) | string (defaults to the currently matched path) |
| nginx.ingress.kubernetes.io/session-cookie-samesite | SameSite attribute to apply to the cookie | Browser accepted values are None, Lax, and Strict |
| nginx.ingress.kubernetes.io/session-cookie-conditional-samesite-none | Will omit SameSite=None attribute for older browsers which reject the more-recently defined SameSite=None value | “true” or “false” |
| nginx.ingress.kubernetes.io/session-cookie-max-age | Time until the cookie expires, corresponds to the Max-Age cookie directive | number of seconds |
| nginx.ingress.kubernetes.io/session-cookie-expires | Legacy version of the previous annotation for compatibility with older browsers, generates an Expires cookie directive by adding the seconds to the current date | number of seconds |
| nginx.ingress.kubernetes.io/session-cookie-change-on-failure | When set to false nginx ingress will send request to upstream pointed by sticky cookie even if previous attempt failed. When set to true and previous attempt failed, sticky cookie will be changed to point to another upstream. | true or false (defaults to false) |
You can create the example Ingress to test this:
bash-3.2$less ingress.yaml
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:name: nginx-testannotations:nginx.ingress.kubernetes.io/affinity: "cookie"nginx.ingress.kubernetes.io/session-cookie-name: "route"nginx.ingress.kubernetes.io/session-cookie-expires: "172800"nginx.ingress.kubernetes.io/session-cookie-max-age: "172800"spec:rules:- host: stickyingress.example.comhttp:paths:- backend:serviceName: http-svcservicePort: 80path: /bash-3.2$kubectl create -f ingress.yaml
验证
You can confirm that the Ingress works:
$ kubectl describe ing nginx-test
Name: nginx-test
Namespace: default
Address:
Default backend: default-http-backend:80 (10.180.0.4:8080,10.240.0.2:8080)
Rules:Host Path Backends---- ---- --------stickyingress.example.com/ nginx-service:80 (<none>)
Annotations:affinity: cookiesession-cookie-name: INGRESSCOOKIEsession-cookie-expires: 172800session-cookie-max-age: 172800
Events:FirstSeen LastSeen Count From SubObjectPath Type Reason Message--------- -------- ----- ---- ------------- -------- ------ -------7s 7s 1 {nginx-ingress-controller } Normal CREATE default/nginx-test$ curl -I http://stickyingress.example.com
HTTP/1.1 200 OK
Server: nginx/1.11.9
Date: Fri, 10 Feb 2017 14:11:12 GMT
Content-Type: text/html
Content-Length: 612
Connection: keep-alive
Set-Cookie: INGRESSCOOKIE=a9907b79b248140b56bb13723f72b67697baac3d; Expires=Sun, 12-Feb-17 14:11:12 GMT; Max-Age=172800; Path=/; HttpOnly
Last-Modified: Tue, 24 Jan 2017 14:02:19 GMT
ETag: "58875e6b-264"
Accept-Ranges: bytes
traefik Controller
https://docs.traefik.io/routing/providers/kubernetes-ingress/
kind: Ingress
apiVersion: networking.k8s.io/v1beta1
metadata:name: myingressannotations:traefik.ingress.kubernetes.io/service.sticky.cookie: "true"traefik.ingress.kubernetes.io/service.sticky.cookie.name: foobarspec:rules:- host: example.comhttp:paths:- path: /barbackend:serviceName: whoamiservicePort: 80- path: /foobackend:serviceName: whoamiservicePort: 80