nginx image filter

nginx.conf

server {
  # Internal image resizing server.
  server_name localhost;
  listen 8888;

  location /resize {
    alias /var/www/app/current/public/imgs;
    image_filter resize $arg_width $arg_height;
    image_filter_jpeg_quality 75;
    allow 127.0.0.0/8;
    deny all;
  }
}

server {
  listen 80;
  root /var/www/app/current/public;
  
  location ^~ /imgs/ {
    gzip_static on;
    expires max;
    add_header Cache-Control public;

    if ($arg_width) {
      set $resize width;
    }
    if ($arg_height) {
      set $resize "${resize}height";
    }

    if ($uri ~* "^/imgs/(.*)$" ) {
      set $basename $1;
    }

    if ($resize = widthheight) {
      rewrite .* /imgs-resize/$arg_width/$arg_height/$basename last;
    }
    if ($resize = width) {
      rewrite .* /imgs-resize/$arg_width/-/$basename last;
    }
    if ($resize = height) {
      rewrite .* /imgs-resize/-/$arg_height/$basename last;
    }
  }

  location ~* /imgs-resize/(?<width>.+)/(?<height>.+)/(?<image_name>.+) {
    set $image_root /var/www/app/current/public/imgs;
    set $image_path "/resize/${width}/${height}/${image_name}";
    alias $image_root/resize;

    if (!-f $image_root$image_path) {
      proxy_pass http://127.0.0.1:8888/resize/$image_name?width=$width&height=$height;
      break;
    }

    proxy_store          $image_root$image_path;
    proxy_store_access   user:rw  group:rw  all:r;
    proxy_temp_path      /tmp/images;
    proxy_set_header     Host $host;
  }
}