How i can translate uppercase to lowercase letters in a rewrite rule in nginx web server?

Question

I need to translate the address:

www.example.com/TEST in ---> www.example.com/test

Answer 1

Yes, you are going to need perl. If you are using Ubuntu, instead of apt-get install nginx-full, use apt-get install nginx-extras, which will have the embedded perl module. Then, in your configuration file:

  http {
  ...
    # Include the perl module
    perl_modules perl/lib;
    ...
    # Define this function
    perl_set $uri_lowercase 'sub {
      my $r = shift;
      my $uri = $r->uri;
      $uri = lc($uri);
      return $uri;
    }';
    ...
    server {
    ...
      # As your first location entry, tell nginx to rewrite your uri,
      # if the path contains uppercase characters
      location ~ [A-Z] {
        rewrite ^(.*)$ $scheme://$host$uri_lowercase;
      }
    ...

Answer 2

location /dupa/ {
    set_by_lua $request_uri_low "return ngx.arg[1]:lower()" $request_uri;
    rewrite ^ https://$host$request_uri_low;
}

Answer 3

i managed to achieve the goal using embedded perl:

location ~ [A-Z] {
  perl 'sub { my $r = shift; $r->internal_redirect(lc($r->uri)); }';
}

Answer 4

location ~*^/test/ {
  return 301 http://www.example.com/test;
}

A location can either be defined by a prefix string, or by a regular expression. Regular expressions are specified with the preceding “~*” modifier (for case-insensitive matching), or the “~” modifier (for case-sensitive matching).

Soruce: http://nginx.org/en/docs/http/ngx_http_core_module.html#location

Answer 5

Based on Adam's answer, I ended up using lua, as it's available on my server.

set_by_lua $request_uri_low "return ngx.arg[1]:lower()" $request_uri;
if ($request_uri_low != $request_uri) {
   set $redirect_to_lower 1;
}
if (!-f $request_uri) {
    set $redirect_to_lower "${redirect_to_lower}1";
}
if ($redirect_to_lower = 11) {
    rewrite . https://$host$request_uri_low permanent;
}