请问在负载均衡ALB ingress里可以通过annotation实现吗?

在负载均衡ALB ingress中，可以通过添加注解（annotation）来实现一些高级功能，以下是使用注解的一些示例：

1. 自定义HTTP头部

通过添加注解，可以自定义HTTP请求的头部信息，添加一个名为XCustomHeader的自定义头部：

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myingress
  annotations:
    alb.ingress.kubernetes.io/scheme: internetfacing
    alb.ingress.kubernetes.io/listenports: '[{"HTTP": 80}, {"HTTPS":443}]'
    alb.ingress.kubernetes.io/actions.sslredirect: '{"Type": "redirect", "RedirectConfig": { "Protocol": "HTTPS", "Port": "443", "StatusCode": "HTTP_301"}}'
    alb.ingress.kubernetes.io/headers: '{"XCustomHeader": "myvalue"}'
spec:
  ingressClassName: alb
  rules:
  http:
      paths:
      path: /
        pathType: Prefix
        backend:
          service:
            name: myservice
            port:
              number: 80

2. SSL重定向

通过添加注解，可以实现将HTTP请求重定向到HTTPS。

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myingress
  annotations:
    alb.ingress.kubernetes.io/scheme: internetfacing
    alb.ingress.kubernetes.io/listenports: '[{"HTTP": 80}, {"HTTPS":443}]'
    alb.ingress.kubernetes.io/actions.sslredirect: '{"Type": "redirect", "RedirectConfig": { "Protocol": "HTTPS", "Port": "443", "StatusCode": "HTTP_301"}}'
spec:
  ingressClassName: alb
  rules:
  http:
      paths:
      path: /
        pathType: Prefix
        backend:
          service:
            name: myservice
            port:
              number: 80

3. 自定义健康检查路径和状态码

通过添加注解，可以自定义健康检查的路径和状态码。

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myingress
  annotations:
    alb.ingress.kubernetes.io/scheme: internetfacing
    alb.ingress.kubernetes.io/listenports: '[{"HTTP": 80}, {"HTTPS":443}]'
    alb.ingress.kubernetes.io/healthcheckpath: "/custompath"
    alb.ingress.kubernetes.io/healthcheckfailurethreshold: '3'
    alb.ingress.kubernetes.io/healthythresholdcount: '3'
    alb.ingress.kubernetes.io/healthythresholdtime: '5'
    alb.ingress.kubernetes.io/successcodes: '200,201'
spec:
  ingressClassName: alb
  rules:
  http:
      paths:
      path: /
        pathType: Prefix
        backend:
          service:
            name: myservice
            port:
              number: 80

以上示例展示了如何在ALB ingress中使用注解实现自定义HTTP头部、SSL重定向和自定义健康检查路径及状态码。