# How do I redirect/handle requests from search engines via nginx using location regex

**URL:** <https://www.ruby-forum.com/t/how-do-i-redirect-handle-requests-from-search-engines-via-nginx-using-location-regex/219250>\
**Category:** NGINX\
**Created:** [April 25, 2012, 10:41am UTC](https://www.ruby-forum.com/t/how-do-i-redirect-handle-requests-from-search-engines-via-nginx-using-location-regex/219250 "2012-04-25T10:41:46Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Gurdipe\_D](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/b77776/32.png) [@Gurdipe\_D](https://www.ruby-forum.com/u/Gurdipe_D)\
**Post date:** [April 25, 2012, 10:41am UTC](https://www.ruby-forum.com/t/how-do-i-redirect-handle-requests-from-search-engines-via-nginx-using-location-regex/219250/1 "2012-04-25T10:41:46Z")

</div>

Hi,

I have developed an ajax-based web application with hash bang urls.

I am trying to redirect requests from search engines to another server  
which generates HTML snapshots and send the response. I am trying to  
achieve this in nginx with the location directive as mentioned below:

```
  location ~ ^(/?_escaped_fragment_=).*$ {
     proxy_set_header Host $host;
      proxy_set_header X-Real-IP $remote_addr;
  proxy_set_header X-Forwarded-For 

```

$proxy\_add\_x\_forwarded\_for;  
proxy\_set\_header X-Forwarded-Proto $scheme;

```
      client_max_body_size 10m;
      client_body_buffer_size 128k;
      proxy_connect_timeout 60s;
      proxy_send_timeout 90s;
      proxy_read_timeout 90s;
      proxy_buffering off;
      proxy_temp_file_write_size 64k;
      proxy_pass http://x1.x2.x3.x4:8080;
      proxy_redirect off;
  }

```

But I am not able to get this working. Can someone correct the regex I  
am  
using (or) provide me an alternative solution to achieve this.

Thanks in advance,

## Ravi

This message contains confidential information and is intended only for  
the  
individual named. If you are not the named addressee you should not  
disseminate, distribute or copy this e-mail. Please notify the sender  
immediately by e-mail if you have received this e-mail by mistake and  
delete this e-mail from your system. E-mail transmission cannot be  
guaranteed to be secure or error-free as information could be  
intercepted,  
corrupted, lost, destroyed, arrive late or incomplete, or contain  
viruses.  
The sender therefore does not accept liability for any errors or  
omissions  
in the contents of this message, which arise as a result of e-mail  
transmission. If verification is required please request a hard-copy  
version. Pipal Tech Ventures Private Limited ([www.pipaltechventures.com](http://www.pipaltechventures.com))

---

<div class="post-metadata">

**Author:** ![Raviteja\_Dodda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/a587f6/32.png) [@Raviteja\_Dodda](https://www.ruby-forum.com/u/Raviteja_Dodda)\
**Post date:** [April 25, 2012, 9:23pm UTC](https://www.ruby-forum.com/t/how-do-i-redirect-handle-requests-from-search-engines-via-nginx-using-location-regex/219250/2 "2012-04-25T21:23:52Z")

</div>

On Wed, Apr 25, 2012 at 02:10:53PM +0530, Raviteja Dodda wrote:

Hi there,

> I have developed an ajax-based web application with hash bang urls.
> 
> I am trying to redirect requests from search engines to another server  
> which generates HTML snapshots and send the response.

I confess I’m not sure how to tie “requests from search engines” and  
“hash bang urls” into the details of your question. But that probably  
doesn’t matter.

nginx doesn’t care how or why the url arose; it just knows what request  
was made to it, and it processes that request in the one location that  
is configured for the request.

So I’ll (try to) describe what nginx sees and what nginx does, and then  
maybe it will be clear to you how that maps to your application and your  
configuration.

In general, the url is of the form

[http://one](http://one):two/three?four#five

where some of the parts may be missing.

nginx uses the part before the first single / – one:two – to decide  
which server{} to use. (That’s not quite true, but it’s close enough  
for now.)

nginx then is only sent the part from the first single / to just before  
the first # – so all nginx can see is /three?four.

When it comes to matching against the location{}s that are defined,  
nginx stops just before the first ? – in this case, /three

So: can you identify the http requests that are made when someone uses  
your web application? Or the http requests that come from search  
engines?

Then see what is the part that nginx will consider relevant for the  
location matching – from the first single / to just before the first #  
or ? – and then write a location directive to match those.

> I am trying to  
> achieve this in nginx with the location directive as mentioned below:
> 
> ```
> location ~ ^(/?_escaped_fragment_=).*$ {
> 
> ```

There is one subtlety, in that it is possible for nginx to consider  
? to be part of the url that can be matched in the location directive;  
but only if it was properly url-encoded originally (which means that  
the client did not ask for /?four, but for something like /%3ffour).

But that’s not a common setup; so I’m going to guess that you are not  
using that, in which case the request that it looks like you are trying  
to match is exactly “/”.

> But I am not able to get this working. Can someone correct the regex I am  
> using (or) provide me an alternative solution to achieve this.

Hopefully the above gives you enough information to find the answer.

If not, if you can include one url that you are attempting to access  
(ideally using something like curl, so that it is easily repeatable  
without being concerned with browser caching), and the response you  
expect  
and the response you get, then someone may be able to provide more help.

## f

Francis D. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)