仅当目录不存在时，才如何从nginx中的URL删除尾部斜杠?

我正在使用PHP-FastCGI在nginx 1.4.1上运行服务器.目前，我已对其进行设置，以使其从我的URL中删除结尾的斜杠并发出301重定向.但是，当我访问一个存在的目录时，我被迫进入重定向循环.我当前的文档根目录如下:

I am running a server on nginx 1.4.1 with PHP-FastCGI. Currently I have it setup so that it removes trailing slashes from my URLs and issues a 301 redirect. However, when I visit a directory that exists, I am forced into a redirect loop. My current document root looks like this:

- index.php (app)
- webgrind
    - index.php
- static 
    - css

当前，我无法访问example.com/webgrind或任何其他目录.我的访问日志反复读取类似于:

Currently I cannot visit example.com/webgrind or any other directory. My access logs repeatedly read similar to:

GET /webgrind/ HTTP/1.1" 301 178 "-"
GET /webgrind  HTTP/1.1" 301 178 "-"

这是我的nginx.conf中的服务器块:

This is the server block in my nginx.conf:

server {
        listen 80;
        server_name example.com;

        location / {
            try_files $uri $uri/ /index.php?$args;
            root /var/www/example/public;
            index  index.php index.html index.htm;
        }

        rewrite ^/(.*)/$ /$1 permanent;

        location = /favicon.ico {
            access_log     off;
            log_not_found  off;
        }

        location ~ \.php$ {
            try_files $uri $uri/ /index.php?$args;
            root /var/www/example/public;
            index index.php index.html index.htm;

            fastcgi_pass   unix:/var/run/php5-fpm.sock;
            fastcgi_index  index.php;
            fastcgi_param  SCRIPT_FILENAME  /var/www/example/public$fastcgi_script_name;
            fastcgi_param  APPLICATION_ENV testing;
            fastcgi_param  PATH /usr/bin:/bin:/usr/sbin:/sbin;
            fastcgi_intercept_errors on;
            include        fastcgi_params;
        }
    }

我知道rewrite ^/(.*)/$ /$1 permanent;是违规行.如果我删除它并访问example.com/webgrind，由于它是一个目录，因此会发出301重定向到example.com/webgrind/.但是，我的应用程序现在将接受尾随和非尾随的斜杠(即example.com/users/和example.com/users)，这不是我想要的.

I am aware that rewrite ^/(.*)/$ /$1 permanent; is the offending line. If I remove it and visit example.com/webgrind, a 301 is issued for me to redirect to example.com/webgrind/ since it is a directory. However, my application will now accept both trailing and non-trailing slashes (i.e. example.com/users/ and example.com/users) and this is not what I want.

如下所示，将'if'指令包装在我的重写周围，仍然为我的目录创建重定向循环( if是邪恶的，但是在这种情况下，重写指令被认为是安全的):

Wrapping the 'if' directive around my rewrite as follows still creates a redirect loop for my directories (if is evil, apparently, but a rewrite directive in this case is considered safe):

if (!-d $request_filename) {
    rewrite ^/(.*)/$ /$1 permanent;
}

(我知道访问webgrind/index.php可以解决我的问题，但是当我的生产目录实时发布时，我想避免昂贵且不专业的重定向循环.)

那么我如何有条件地仅对不存在的资源(我的Web应用程序路径)去除尾部斜杠?

So how can I conditionally strip trailing slashes only for resources that don't exist (my web application paths)?

更新:我的(未更改)fastcgi_params配置:

UPDATE: My (unaltered) fastcgi_params config:

fastcgi_param   QUERY_STRING            $query_string;
fastcgi_param   REQUEST_METHOD          $request_method;
fastcgi_param   CONTENT_TYPE            $content_type;
fastcgi_param   CONTENT_LENGTH          $content_length;

fastcgi_param   SCRIPT_FILENAME         $request_filename;
fastcgi_param   SCRIPT_NAME             $fastcgi_script_name;
fastcgi_param   REQUEST_URI             $request_uri;
fastcgi_param   DOCUMENT_URI            $document_uri;
fastcgi_param   DOCUMENT_ROOT           $document_root;
fastcgi_param   SERVER_PROTOCOL         $server_protocol;

fastcgi_param   GATEWAY_INTERFACE       CGI/1.1;
fastcgi_param   SERVER_SOFTWARE         nginx/$nginx_version;

fastcgi_param   REMOTE_ADDR             $remote_addr;
fastcgi_param   REMOTE_PORT             $remote_port;
fastcgi_param   SERVER_ADDR             $server_addr;
fastcgi_param   SERVER_PORT             $server_port;
fastcgi_param   SERVER_NAME             $server_name;

fastcgi_param   HTTPS                   $https;

# PHP only, required if PHP was built with --enable-force-cgi-redirect
fastcgi_param   REDIRECT_STATUS         200;