Getting address from address bar after using Apache mod rewrite

URI address php Apache mod_rewrite

[kpkammer]

I'm trying to get the subdomain that is displayed in the address bar.

I'm using the following

mod_rewrite

to redirect people accessing a subdomain to view another subdomain (transparently)

RewriteEngine on
RewriteCond %{HTTP_HOST} ^(.+)\.domain\.com
RewriteRule ^(.*)$ http://test.domain.com/$1?sub=%1 [P]

So when users go to

http://anotherone.domain.com/login.php

the URL in the address bar will not change but

http://test.domain.com/login.php

will be loaded.

However the below code does NOT help:

echo $_SERVER['HTTP_HOST'];
echo $_SERVER['SERVER_NAME'];

They return

test.domain.com

and I'm trying to get

anotherone.domain.com

Please help! :)

[phranque]

welcome to WebmasterWorld, kpkammer!

you cannot rewrite to another hostname.
when you specify the protocol and hostname in the RewriteRule that implies an external redirect.

you must either rewrite to a resource on the same virtual host or use a proxy server.

[kpkammer]

Thanks!

I'm not sure exactly what you're saying, because the mod_rewrite is not using an external redirect. It is working as I described it.

When users go to

http://anotherone.domain.com/login.php

the URL in the address bar will not change but

http://test.domain.com/login.php

will be loaded.

I just want to be able to find

anotherone.domain.com

[tommytx]

Can we get some clarification. Is the rewrite working ok but when you try to read the domain it is not providing the results you want..
Do you mean when your use this code in a php file located on the landing domain it is showing the current subdomain and not the domain they came from... what you are trying to do is really confusing.
echo $_SERVER['HTTP_HOST'];
echo $_SERVER['SERVER_NAME'];

IF you could start over and use an actual domain name (even ficticious) we can help you....

For example lets name the original folks say come in to your site on
sam.mydomain.com and they are being redirected correctly to bill.mydomain.com.

But when you read the
echo $_SERVER['HTTP_HOST'];
echo $_SERVER['SERVER_NAME'];
it is reporting to you that it is bill.mydomain.com and you want it to actually report the domain they were originally coming to which was sam.mydomain.com

Using absolute domain names will help up follow you better....

[kpkammer]

Your example is exactly what I'm trying to do.

I'm trying to do this because I have a web based application that I want to have 1 code base, but unique to each sub domain. I was originally using $_SERVER['SERVER_NAME']; to be the key of my database to pull information for each sub domain.

So in the end I want all the sub domains Sam.mydomain.com fred.mydomain.com tom.mydomain.com to point to the code base bill.mydomain.com and I want to be able to read what the URL says (Sam, etc) so I can configure the code base uniquely each time.

[g1smd]

What you have here is not a redirect or rewrite, it's a Proxy pass-through.

Request arrives at server A. Server A asks server B for some content over the web. Server B sends it back to Server A over the web. Server A sends it back to whatever made the original request. This is double the work, and unless you take appropriate steps various things in the original request header don't make it through to the server where the content actually resides.

In this case Server A and Server B appear to be the same machine. If you continue with this method, you will need to look at the various

X-FORWARDED-____

headers, and you'll need to configure both servers to detect and/or set these.

Since this is all the same base hostname you should probably be looking to use internal rewrites for this, and then the information you want will be more readily available.

[edited by: g1smd at 7:42 pm (utc) on Sep 16, 2012]

[phranque]

i missed the [P] flag in your RewriteRule.
do you have mod_proxy enabled?

[lucy24]

it's a Proxy pass-through

You're trying to confuse us again, aren't you? In Apache-speak, "proxy" and "passthrough" are different things:

proxy [P] Force the substitution URL to be internally sent as a proxy request.

passthrough [PT] Forces the resulting URI to be passed back to the URL mapping engine for processing of other URI-to-filename translators, such as Alias or Redirect.

Both carry an implied [L].

Not all hosts are alike, but quick detour to my list of available mods shows that I've got mod_proxy. Also a long string of mod_proxy_{morestuff}. Also-- woo hoo, never realized I had access to it myself-- mod_security (third party, good for squashing evil robots).


Nice going, moderators. Thread was moved at the precise instant I hit Preview, making me wonder what on earth could have caused it to be locked :)

[kpkammer]

I'm really new to this, could you explain this a little more (with an example if possible) :)

Since this is all the same base hostname you should probably be looking to use internal rewrites for this, and then the information you want will be more readily available.

---

I don't know about this?

do you have mod_proxy enabled?

---

Or if you have a suggestion on how I could do this differently/more easily?
Thanks!

[lucy24]

Before everyone starts going off in different directions:

Do the domain and the subdomain physically live on the same server?

If it's shared hosting (I assume yes, or you'd know for sure which mods you have), are the domain and subdomain in the same userspace?

If yes to both, then you almost certainly don't need to mess about with proxies at all. A quiet rewrite should do it. In fact a proxy is just a fancier and more energy-intensive variant on the ordinary rewrite. So your final code will probably be easier to understand and maintain than what you've got now :)

[kpkammer]

You're correct, the answer is yes to both.

The reason I was using the proxy

[P]

is so the URL doesn't change. When a user goes to sam.domain.com, I want them to see sam.domain.com (not codebase.domain.com).

Is there a way for me to accomplish this without using the proxy?

Thanks again!

[kpkammer]

I'm just going to write a cookie and use that.

RewriteEngine on
RewriteCond %{HTTP_HOST} ^(.+)\.domain\.com
RewriteRule ^(.*)$ http://codebase.domain.com/$1 [P,CO=subdomain:%1:.domain.com:126144000:/]

Thanks everyone!