Forum: NGINX Issue with auto subdomain nd trailing slash

Hi All,

I am running into a weird issue, after having configured nginx 0.7.67 
(comes
with debian 6) for serving PHP pages, with automatic subdomains.
It works fine for the most part, but when requesting a url that 
correspond
to an actual folder, but without a trailing slash, the subdomain 
recognition
fails.

Here is the start of the config:

server {

    listen 80;

    # base domain
    set $root_domain XXXX.net;

    server_name XXXX.net *.XXXX.net;

    if ($host ~* ^www\.XXXX\.net$) {
      rewrite ^(.*) $scheme://XXXX.net$1 permanent;
      break;
    }

    set $sub_domain "";
    if ($host ~* ^(.*)\.XXXX\.net$) {
      set $sub_domain $1;
    }

    if ($sub_domain) {
# debugging instruction: figure out what's the value of $host
rewrite ^ http://google.com?q=$host permanent;
break;
     set $root_path /var/www/$root_domain/$sub_domain/public;
    }

    if ($sub_domain = "") {
# debugging instruction: figure out what's the value of $host
rewrite ^ http://google.com?q=$host permanent;
break;
      set $root_path /var/www/$root_domain/www/public;
    }

 #if the directory doesn't exist, prevent access
    if (!-d $root_path) {
        return 403;
    }

    #if we have made it here, set the root to the computed directory
    root $root_path;

    # logging
    access_log  /var/log/nginx/$sub_domain.$root_domain.access.log;
    error_log   /var/log/nginx/$sub_domain.$root_domain.error.log;

    location / {
        index  index.html index.php;

        # serve static files that exist without running other rewrite 
tests
        if (-f $request_filename) {
            expires  30d;
            break;
        }

        # send all non-existing file or directory requests to index.php
        if (!-e $request_filename) {
            rewrite  ^/(.*)  /index.php  last;
        }
    }

    # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
    try_files $uri =404;
    location ~ \.php$ {
        include /etc/nginx/fastcgi_params;
        fastcgi_pass   127.0.0.1:9000;
        fastcgi_index  index.php;
        fastcgi_param  SCRIPT_FILENAME  $root_path$fastcgi_script_name;
    }


    # optional authentication
    # would require to be put in its own server block
    # if only valid for some sub-domais
    #location / {
    #      auth_basic            "Authentication Required";
    #      auth_basic_user_file  $root_path/private/authfile;
    #}


    location ~ /\.ht{
        deny all;
    }
}


With this setup, you can access XXXX.net and any subdomain is served 
based
on the corresponding folder under web root. All of that works very fine
except in one case:

If you request: http://subD1.XXXX.net/admin/, and /admin/ is a folder 
under
the subD1 web site, everything goes well, the index file (index.php) is
served.
Now if one requests http://subD1.XXXX.net/admin (without trailing 
slash),
the sub domain is not recognized anymore, and the root path is set to 
the
path to XXXX.net instead of that associated with subD1.

Now the real weird thing is that it is the $host variable that's wrong. 
In
the first case (request for a folder with trailing slash), $host 
contains
subD1.XXXX.net, and the regexp matches, the sub domain is properly
calculated.
In the second case (no trailing slash), $host is wrong: it contains 
XXXX.net
instead of subD1.XXXX.net, and so the regexp doesn't match and the sub
domain is not recognized.

Please note that my question is not about trying to redirect urls with 
or
without trailing slash to its counterpoint. My issue is with the 
subdomain
regexp not matching because the $host value is wrong.

Any pointer as to what's going on? Am I doing something wrong?

Thanks for any pointer and best regards

Posted at Nginx Forum: 
http://forum.nginx.org/read.php?2,236469,236469#msg-236469

On Fri, Feb 22, 2013 at 06:27:27AM -0500, shumisha wrote:

> I am running into a weird issue, after having configured nginx 0.7.67 (comes
> with debian 6) for serving PHP pages, with automatic subdomains.
> It works fine for the most part, but when requesting a url that correspond
> to an actual folder, but without a trailing slash, the subdomain recognition
> fails.

What is probably happening is that when you ask for /dir, you get a http
redirect to /dir/. That redirect must include the full url, including
the hostname. And nginx has to choose which hostname to use. And it
doesn't choose the one that you want it to choose.

What is the output of

  curl -i http://subD1.XXXX.net/admin

? I guess it will show http://XXXX.net/admin/. You then separately
request http://XXXX.net/admin/, and therefore shouldn't be surprised
that the subdomain recognition fails, because in this request there is
no subdomain.

Possibly setting server_name_in_redirect
(http://nginx.org/r/server_name_in_redirect) to "off" will work for
you? The docs say that default is off, but I think that may have been
different in the 0.7 series.

  f
--
Francis Daly        francis@daoine.org

Hi Francis,

Thanks a lot for your message, I think I got things under control thanks 
to
you!

You're right, there's indeed a 301 thrown by nginx from
http://subdomain.xxxx.net/admin to http://xxxx.net/admin/
(as shown by the curl output).

I had tried server_name_in_redirect to off before, to no avail, but I 
tried
again, just in case. I looked up the documentation again, and I 
realized:

- it's probably not active on my version, as nginx still uses the first
server in the server_name directive regardless of the directive value.
However, it's a valid config value
- but that got me thinking and I simply switched the orders of server, 
so
that it reads:

server_name *.xxxx.net xxxx.net;

So now the automatic redirect still happens (I think it should be
configurabe, maybe it is) but by placing the *.xxxx.net server first in 
the
server_name directive, the sub domain is preserved and the redirect now
happens with the correct host.

Thanks again for your help :)

Rgds

Posted at Nginx Forum: 
http://forum.nginx.org/read.php?2,236469,236477#msg-236477