Question:

Some time ago I developed a shortlink service (like goo.gl).

Shortlinks in the browsers addressbar are displayed as example.com/Lg1Q

Recently I migrated from Lighty to Nginx, due to performance benefits. In Lighttpd I used

url.rewrite-if-not-file = ( "^/(.*)(\?.*)?$" => "/index.php?fwd=$1" )

to hand over the "Lg1Q" part from the URL to the index.php script.

The index.php script processes the not-file-part from the URL as follows:

if ( !empty( $myUrl ) && $_SERVER['REQUEST_URI'] !== '/index.php' && $_SERVER['REQUEST_URI'] !== '/index.html' && $_SERVER['REQUEST_URI'] !$ $query = htmlspecialchars( str_replace("fwd=","", $_SERVER['QUERY_STRING']) ); require_once 'src/clsForwardURL.class.php'; $myForward = new clsForwardURL(); $url = $myForward->fForwardURL( $query ); $url = ( $url[0]['su_longurl'] ); echo header( 'location:'.$url ); }//end if

I tried to rebuild the rewrite rule from Lighttpd to Nginx syntax like:

rewrite "^/(.*)(\?.*)?$" /index.php?fwd=$1;

After that, I inserted this rule subsequently in the location ~ \.php block and the location / block of the nginx host container in /etc/nginx/sites-available.

Unfortunally in both cases the browser showed a '404' or a '500' error.

My question is: How can I properly setup the rewrite rule for the 'shortlink' purpose?

The rewrite in the location / block will rewrite everything - not just your short URIs. You could qualify the rewrite operation using a try_files statement. See <a href="http://nginx.org/en/docs/http/ngx_http_core_module.html#try_files" rel="nofollow">this document</a> for more.

For example:

location / { try_files $uri $uri/ @rewrite; } location @rewrite { rewrite ^/(.*)$ /index.php?fwd=$1 last; }

Notice that the query string component is not part of the normalised URI used by the rewrite directive. See <a href="http://nginx.org/en/docs/http/ngx_http_rewrite_module.html#rewrite" rel="nofollow">this document</a> for more.

You can simplify the above further, if you modify the PHP code to accept a leading / in the fwd parameter, in which case you could use:

location / { try_files $uri $uri/ /index.php?fwd=$uri; }

You don't need a rewrite, the whole capture logic can be in the root location itself, e.g:

location ~ \.php$ { ... } # using a name variable instead of $1 location ~ ^/(?<short_url>.*)$ { try_files $uri $uri/ /index.php?fwd=$short_url; }