Nginx + Image filter (resize/crop) + Proxy cache (optional) + Secure link (optional)

nginx.conf

# nginx.conf
load_module /etc/nginx/modules/ngx_http_image_filter_module.so;

# host.conf
proxy_cache_path /tmp levels=1:2 keys_zone=thumbs:10m inactive=24h max_size=100M;

server {
    listen 80;

    root /usr/share/nginx/html;

    location /i/ {
        # comment if not used secure link
        # echo -n '/i/crop/100x100/test.jpg SECURE' | openssl md5 -binary | openssl base64 | tr +/ -_ | tr -d =
        # ruby convert Base64.encode64(url).gsub('+','-').gsub('/','_').gsub('=','').strip
        secure_link $arg_hash;
        secure_link_md5 "$uri SECURE";
        if ($secure_link = "") {
          return 403;
        }
        if ($secure_link = "0") {
          return 418;
        }
        
        gzip_static on;
        expires max;
        add_header Cache-Control public;

        proxy_pass http://127.0.0.1:8080;
        
        # comment if not used proxy cache
        proxy_cache thumbs;
        proxy_cache_valid  200      24h;
        proxy_cache_valid  404 415  1m;
    }
}

server {
  listen 127.0.0.1:8080;

  root /usr/share/nginx/html;

  image_filter_buffer         10m;
  image_filter_jpeg_quality   90;
  image_filter_interlace      on;

  location ~ ^/i/resize/(?<width>\d+|-)x(?<height>\d+|-)(?<path>/.*?\.(?:jpg|gif|png))$ {
      rewrite ^.*$ /$path;
      image_filter resize $width $height;
      break;
  }

  location ~ ^/i/crop/(?<width>\d+|-)x(?<height>\d+|-)(?<path>/.*?\.(?:jpg|gif|png))$ {
      rewrite ^.*$ /$path;
      image_filter crop $width $height;
      break;
  }
}