Adding proxy cache date

to check how long my cache will exist

Signed-off-by: Rajesh Rajendran <rjshrjndrn@gmail.com>

kubernetes/helm_charts/core/nginx-public-ingress/values.j2

@@ -212,6 +212,7 @@ proxyconfig: |
       proxy_cache_key "$request_uri|$request_body";
       proxy_cache framework_cache;
       add_header X-Proxy-Cache $upstream_cache_status;
+      add_header X-Proxy-Cache-Date $upstream_http_date;
       proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504;
       proxy_cache_methods GET HEAD POST;
       proxy_cache_background_update on;
@@ -237,6 +238,7 @@ proxyconfig: |
       proxy_cache_key $proxy_host$request_uri;
       proxy_cache framework_cache;
       add_header X-Proxy-Cache $upstream_cache_status;
+      add_header X-Proxy-Cache-Date $upstream_http_date;
       proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504;
       proxy_cache_background_update on;
       proxy_cache_lock on;
@@ -662,6 +664,7 @@ proxyconfig: |
       proxy_cache_key $proxy_host$request_uri;
       proxy_cache proxy_cache;
       add_header X-Proxy-Cache $upstream_cache_status;
+      add_header X-Proxy-Cache-Date $upstream_http_date;
       proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504;
       proxy_cache_background_update on;
       proxy_cache_lock on;
@@ -679,6 +682,7 @@ proxyconfig: |
       proxy_cache_key $proxy_host$request_uri;
       proxy_cache framework_cache;
       add_header X-Proxy-Cache $upstream_cache_status;
+      add_header X-Proxy-Cache-Date $upstream_http_date;
       proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504;
       proxy_cache_background_update on;
       proxy_cache_lock on;