Question on Rewrite / If statements

[Resicow]

Hi Maxim,

Thanks! Never even thought of doing that with just a reg exp that way - 
I was able to adapt this and make it work!

It's amazing how powerful nginx really is. We have fairly low traffic, 
and some big boxes, so I'm not too concerned with the added performance 
penalty / overhead of the if / rewrite module.

I know it is ugly, but the rewrite module does allow us to do some great 
things at the server level, that we used to have to do in php.

Thanks again, and I'm going to brush up on my reg exp skills a little 
tonight.

John




Maxim Dounin wrote:
> Hello!
>
> On Fri, Sep 18, 2009 at 10:28:50AM -0500, Resicow wrote:
>
>   
>> Hi Igor,
>>
>> Thanks for your response.
>>
>> We have lots of virtual hosting domains setup, using $host to point
>> to the correct root directory. This way we can add / subtract
>> domains without touching the nginx config.
>>
>> Similar to the "Wildcard Subdomains in a Parent Folder" at
>> http://wiki.nginx.org/NginxVirtualHostExample
>>
>> This has been working perfectly for us, however we want to stop
>> leeching by checking the HTTP Referer.
>>
>> Since the configuration is "virtual", only the $host variable
>> actually "knows" the name of the vhost.
>>
>> So we want to test to ensure that either $http_referer contains
>> $host (using an if statement), or using the HTTP Referer module with
>> something like this:
>>
>> valid_referers none blocked $host;
>>
>> Can you think of anyway to have nginx test two variables in this
>> fashion? Because of our setup, it is not possible to manually enter
>> these values in the config file, or manually setup a vhost for each
>> domain.
>>     
>
> As a workaround you may use something like:
>
>     set $blah "$host:$http_host";
>
>     if ($blah ~ "^([^:]+):\1$") {
>         return 403;
>     }
>
> Maxim Dounin
>
>
>   
>> Thanks,
>>
>> John
>>
>>
>>
>>
>>
>> Igor Sysoev wrote:
>>     
>>> On Wed, Sep 16, 2009 at 08:03:26PM -0500, Resicow wrote:
>>>
>>>       
>>>> Hello,
>>>>
>>>> I have learned that the http_referer module does *not* support variables.
>>>>
>>>> I am trying to work around this with if / rewrite statements,
>>>> but may have run into the same issue.
>>>>
>>>> How can I make this work?
>>>>
>>>> set $myvar mydomain.com;
>>>> if ($http_referer ~* $myvar) {
>>>> do something
>>>> }
>>>>
>>>> When I run that, it always returns false. However this works:
>>>>
>>>> if ($http_referer ~* mydomain.com) {
>>>> do something
>>>> }
>>>>
>>>> It appears that the if statement doesn't evaluate the variable.
>>>> Is there anyway around this?
>>>>         
>>> Yes, "if" is ugly hack and it does not evaluate a right part of expression.
>>>
>>> What task do you want to resolve using $http_referer ?
>>>
>>>
>>>       
>>     
>
>