Add support for proxy-hide-headers

[autherlj]

Is this a request for help? (If yes, you should use our troubleshooting guide and community support channels, see https://kubernetes.io/docs/tasks/debug-application-cluster/troubleshooting/.):

What keywords did you search in NGINX Ingress controller issues before filing this one? (If you have found any duplicates, you should instead reply there.):

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Is this a BUG REPORT or FEATURE REQUEST? (choose one):

NGINX Ingress controller version:
nginx-ingress-controller:0.9.0

Kubernetes version (use kubectl version):

Client Version: version.Info{Major:"1", Minor:"8", GitVersion:"v1.8.4", GitCommit:"9befc2b8928a9426501d3bf62f72849d5cbcd5a3", GitTreeState:"clean", BuildDate:"2017-11-20T05:28:34Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"8", GitVersion:"v1.8.4", GitCommit:"9befc2b8928a9426501d3bf62f72849d5cbcd5a3", GitTreeState:"clean", BuildDate:"2017-11-20T05:17:43Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}

Environment:

• Cloud provider or hardware configuration: Azure
• OS (e.g. from /etc/os-release): Ubuntu 17.04
• Kernel (e.g. uname -a): Linux 4.10.0-42-generic Fix unittests #46-Ubuntu SMP Mon Dec 4 14:38:01 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
• Install tools:
• Others:

What happened:
I am using [https://github.com/kubernetes/ingress-nginx/tree/master/deploy] Mandatory commands to deploy nginx-control with rbac. I want to pass proxy-hide-headers: Content-Encoding to nginx.conf by configMap, but it is not working, I have tried both for Annotations:nginx.org/proxy-hide-headers: Content-Encoding kind: ingress also cannot working. I am not sure is rbac have problem any addition config needed?

What you expected to happen:
I want proxy-hide-headers: Content-Encoding can write in the nginx.conf http part by using configMap.

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know:

[autherlj]

in fact, why I need this is I hit two Content-Encoding respones that cannot gzip by chrome, if I using the nginx-control

Response Headers
view source
Access-Control-Allow-Headers:ISC-Auth-Token
Access-Control-Allow-Headers:x-requested-with
Access-Control-Allow-Methods:POST
Access-Control-Allow-Methods:POST, GET,PUT, OPTIONS, DELETE
Access-Control-Allow-Origin:*
Access-Control-Max-Age:3600
Cache-Control:no-cache, no-store, must-revalidate
Connection:keep-alive
Content-Encoding:
Content-Encoding:gzip
Content-Type:application/json
Date:Thu, 11 Jan 2018 07:26:15 GMT

[https://trac.nginx.org/nginx/ticket/1406] and I looked this same issues for nginx1.8