Redirect all URLs to other (external) site except for one path?

CDuv

10/11/23, 10:18 AM

I have a working website (http://www.example.com) that (uses PHP-FPM) for which I want to redirect all incoming trafic to an URL on another website (ttps://www.other-example.com/foo.html) except one specific path (/api).

Here is the Nginx configuration I tried (put the PHP handling stuff in a dedicated location for /api and a return 301 on location /):

upstream php {
    server unix:/var/run/php/php7.4-fpm.sock;
}

server {
    listen 80;
    listen [::]:80;

    server_name www.example.com;

    root /var/www/www.example.com;
    index index.php;

    location  ~ ^/api(?:/(.*))?$ {
        #return 418;
        try_files $uri $uri/ /index.php$is_args$args;
    
        location ~ \.php$ {
            #include snippets/fastcgi-php.conf;

            # regex to split $uri to $fastcgi_script_name and $fastcgi_path
            fastcgi_split_path_info ^(.+?\.php)(/.*)$;

            # Check that the PHP script exists before passing it
            try_files $fastcgi_script_name =404;

            # Bypass the fact that try_files resets $fastcgi_path_info
            # see: http://trac.nginx.org/nginx/ticket/321
            set $path_info $fastcgi_path_info;
            fastcgi_param PATH_INFO $path_info;

            fastcgi_index index.php;
            include fastcgi.conf;
            include fastcgi_params;

            fastcgi_pass php;
        }
    }

    location / {
        return 301 https://www.other-example.com/foo.html;
    }
}

But all my requests (http://www.example.com, http://www.example.com/foo and http://www.example.com/api) gets a HTTP/1.1 301 Moved Permanently with Location: https://www.other-example.com/foo.html.

I know the location ~ ^/api(?:/(.*))?$ works because if I uncomment the return 418; I get 418 responses for http://www.example.com/api requests but 301 for the other requests.

697

1 + 2

nginx

redirect

Richard Smith

10/11/23, 10:39 AM

Where is `index.php`. Your `try_files` sends requests to `/index.php` which is not handled by the `/api` location. Should it `/api/index.php`?

CDuv

10/11/23, 2:44 PM

I see what you mean, but the API is handled by the same PHP application that handles (handled in fact) the other pages, and it's entrypoint is the `index.php` located at `/var/www/www.example.com/index.php`.

Score:0

Server

Tero Kilkanen

10/11/23, 11:06 PM

The nginx processing goes as follows in your case:

Request to /api/test_endpoint matches the location ~ ^/api(?:/(.*))?$ block.
In try_files, it matches the /index.php$is_args$args part. Since it is the last part, it triggers an internal redirect.
nginx restarts the processing with uri /index.php. This matches location / block, which triggers the redirect.

One solution to address the issue is the following configuration:

location  ~ ^/api(?:/(.*))?$ {
    #return 418;
    try_files $uri $uri/ /index.php$is_args$args;
}

location / {
    return 301 https://www.other-example.com/foo.html;
}

location = /index.php {
    internal;
    #include snippets/fastcgi-php.conf;

    # regex to split $uri to $fastcgi_script_name and $fastcgi_path
    fastcgi_split_path_info ^(.+?\.php)(/.*)$;

    # Check that the PHP script exists before passing it
    try_files $fastcgi_script_name =404;

    # Bypass the fact that try_files resets $fastcgi_path_info
    # see: http://trac.nginx.org/nginx/ticket/321
    set $path_info $fastcgi_path_info;
    fastcgi_param PATH_INFO $path_info;

    fastcgi_index index.php;
    include fastcgi.conf;
    include fastcgi_params;

    fastcgi_pass php;
}

With this configuration, nginx finds a match for index.php in step 3 of the request processing. The internal keyword prevents external requests to /index.php matching this block. External requests to /index.php will be served by location / block.

+ 1

CDuv

10/12/23, 2:19 PM

Thanks, it works. I know understand with the `try_files` made things go wrong.

Elon Musk

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EN: Redirect all URLs to other (external) site except for one path?

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