nginx remote file proxying

remotefiles.conf

location ~* ^/remote-files/(http[s]*://)(.*?)/(.*) {
          # Do not allow people to mess with this location directly
          # Only internal redirects are allowed
          internal;
          
          # nginx has to be able to resolve the remote URLs
          resolver 8.8.8.8;

          # Location-specific logging
          #access_log /usr/local/etc/nginx/logs/internal_redirect.access.log main;
          error_log /usr/local/etc/nginx/logs/internal_redirect.error.log warn;

          # Extract download url from the request
          set $download_uri $3;
          set $download_host $2;
          set $download_protocol $1;

          # Compose download url
          set $download_url $download_protocol$download_host/$download_uri;

          # The next two lines could be used if your storage 
          # backend does not support Content-Disposition 
          # headers used to specify file name browsers use 
          # when save content to the disk
          proxy_hide_header Content-Disposition;
          add_header Content-Disposition 'attachment; filename="$args"';

          # Do not touch local disks when proxying 
          # content to clients
          proxy_max_temp_file_size 0;

          # Download the file and send it to client
          proxy_pass $download_url;
        }

There's no reason to parse out and reconstruct the url unless there's a desire to set the Host header as demonstrated in other example. Simplifying the regex results in a more concise definition:

location ~ ^/remote-files/(.+) {
   internal;
   resolver 8.8.8.8; # nginx has to be able to resolve the external url
   proxy_pass $1;
}