ingress的rewrite作用

前提需求：

Ingress targets exactly one Ingress controller by specifying the ingress.class annotation；（yaml有重定向注解部分）

 you have an ingress controller running in your cluster.（集群部署有ingress controller）

包含四种注解说明：

nginx.ingress.kubernetes.io/rewrite-target

nginx.ingress.kubernetes.io/ssl-redirect

nginx.ingress.kubernetes.io/force-ssl-redirect

nginx.ingress.kubernetes.io/app-root

nginx.ingress.kubernetes.io/use-regex

Captured groups are saved in numbered placeholders, chronologically, in the form $1, $2 ... $n. These placeholders can be used as parameters in the rewrite-target annotation.（通俗就是以path匹配的第一个()括号为$1。以此为顺序排序）

例子（实现、*.com/ 跳转*.com/abc）：

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: nacos-headless
  namespace: nacos
  annotations:
    kubernetes.io/ingress.class: "nginx"
    nginx.ingress.kubernetes.io/app-root: /nacos/
    nginx.ingress.kubernetes.io/rewrite-target: /nacos/$2
    #nginx.ingress.kubernetes.io/configuration-snippet: |
      #rewrite ^(/nacos)$ $1/ redirect;
spec:
  rules:
  - host: *.com
    http:
      paths:
      - backend:
          serviceName: nacos-headless
          servicePort: server
        path: /nacos(/|$)(.*)