How do I not force a redirect if it's from a social media site like reddit,facebook & twitter? Currently my setting is set to redirect any direct access to image files but I don't want to redirect if it's from social media sites so it can fetch image preview.
proxy_cache_path /var/www/img.example.com/htdocs/cache-store levels=1:2 keys_zone=pixstore:10m max_size=5g inactive=7d use_temp_path=off;
server {
server_name img.example.com www.img.example.com;
access_log /var/log/nginx/img.example.com.access.log ;
error_log /var/log/nginx/img.example.com.error.log;
add_header X-Proxy-Cache $upstream_cache_status;
location / {
proxy_cache pixstore;
proxy_cache_revalidate on;
proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504;
proxy_cache_lock on;
add_header X-Cache-Status $upstream_cache_status;
proxy_pass http://xxx.xxx.xxx.xxx:8090;
proxy_redirect off;
include proxy_params;
proxy_cache_valid 200 7d;
proxy_cache_valid 404 5m;
}
location ~ "^/c/600x1200_90_webp/img-master/img/\d+/\d+/\d+/\d+/\d+/\d+/((?<filenum>\d+)[^/]+\.(jpg|png|webp))$" {
proxy_pass http://xxx.xxx.xxx.xxx:8090;
return 301 http://view.example.com/artwork/$filenum;
}
}