I am trying to rate limit number GRPC connections based on a token included in the Authorization header. I tried the following settings in the Nginx configmap and Ingress annotation but Nginx rate limiting is not working.

```
---
apiVersion: v1
kind: ConfigMap
metadata:
name: nginx-ingress-controller
namespace: default
data:
http-snippet: |
limit_req_zone $http_authorization zone=zone-1:20m rate=10r/m;
limit_req_zone $http_token zone=zone-2:20m rate=10r/m;

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/backend-protocol: GRPC
nginx.ingress.kubernetes.io/configuration-snippet: |
limit_req zone=zone-1;
limit_req_log_level notice;
limit_req_status 429;
```
I try to have Nginx Ingress Controller to rate limit the GRPC/HTTP2 stream connection based on the value in the $http_authorization variable. I have modified the Nginx log_format to log the $http_authorization value and observe that Nginx receives the value. The problem I am facing is that for some reason the rate limiting rule doesn't get triggered.

Is this the correct approach?

Any help and feedback would be much appreciated!

Thanks