Nginx 反代 Gravatar

nginx.conf

proxy_cache_path  /home/wwwroot/example.com/cache  levels=1:2   keys_zone=gravatar:10m inactive=7d max_size=1g;
server
{
    listen       80;
    server_name example.com
location / {
       proxy_cache gravatar;
       proxy_cache_valid 200 302 1h;
       proxy_cache_valid 404 1m;
       proxy_redirect off;
       proxy_set_header X-Real-IP $remote_addr;
       proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
       proxy_set_header X-Forwarded-Proto https;
       proxy_pass https://secure.gravatar.com;
       proxy_set_header Host "secure.gravatar.com";
       proxy_set_header Accept-Encoding "";
       proxy_set_header User-Agent $http_user_agent;
  }
    access_log off; #access_log end
    error_log /dev/null; #error_log end
}