在K8S 的ingress上配置HTTP认证的方法如下：

1 . 使用htpasswd创建一个auth文件：

htpasswd -c ./auth myusername
cat auth
myusername:$apr1$78Jyn/1K$ERHKVRPPlzAX8eBtLuvRZ0
  1. 创建一个K8S的secret:
kubectl create secret generic mysecret --from-file auth --namespace=monitoring 
kubectl --namespace=monitoring get secret mysecret 
NAME      TYPE    DATA    AGE 
mysecret Opaque   1      106d
  1. 通过以下参数将创建的secret与ingress关联起来:
ingress.kubernetes.io/auth-type: "basic"
ingress.kubernetes.io/auth-secret: "mysecret"
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
 name: prometheus-dashboard
 namespace: monitoring
 annotations:
   kubernetes.io/ingress.class: traefik
   ingress.kubernetes.io/auth-type: "basic"
   ingress.kubernetes.io/auth-secret: "mysecret"
spec:
 rules:
 - host: dashboard.prometheus.example.com
   http:
     paths:
     - backend:
         serviceName: prometheus
         servicePort: 9090

最后创建就可以了：

kubectl create -f prometheus-ingress.yaml -n monitoring

参考：

https://docs.traefik.io/user-guide/kubernetes/

https://docs.traefik.io/configuration/backends/kubernetes/