Forum: NGINX rewrite help please.

I've got a WP site that also provides landing pages for a number of
other sites. I've set it up as the default server config for that IP,
and that's working fine. However, the requirement I've got is to go to a
specific landing page dependant on domain name. This is how I've gone
about it ( as there are a lot of pages...


map $http_host $page_redirect {
hostnames;

default notset;

.example1.com /link/example1;
...
}

hostname example.com;

location = / {
if ( $page_redirect ~ notset ) {
rewrite ^ /index.php break;
}
# this one works but rewrites the url.
rewrite ^ $page_redirect redirect;
#try_files $page_redirect $page_redirect/ /index.php?$page_redirect;
}

So I'm basically only trying to redirect from http://www.example.com for
example, but not http://www.example.com/index.php, and only from
predefined domains.

As the comment says, this does work if I use a rewrite ... redirect; but
the URL then changes to http://www.example1.com/link/example1, whereas I
want to see http://www.example1.com alone.

The try_files comes up with a 404, which is really perplexing... I
expected it to go through the .php block like the others!

Any ideas what I'm doing wrong?

Cheers,

Steve

On Sun, Dec 09, 2012 at 07:06:01PM +1300, Steve Holdoway wrote:

Hi there,

> I've got a WP site that also provides landing pages for a number of
> other sites. I've set it up as the default server config for that IP,
> and that's working fine.

The usual nginx way is to have a different configuration for each
server_name in different server{} blocks, which is usually based on the
Host: header sent by the browser.

You want slightly different handling for different Host: headers, but
all in the same server{} block. That's ok, but when you start adding
more special cases, you should probably consider switching to multiple
server{} blocks.

> However, the requirement I've got is to go to a
> specific landing page dependant on domain name. This is how I've gone
> about it ( as there are a lot of pages...
>
>
> map $http_host $page_redirect {

Some small points:

$http_host is "whatever the browser sent, including :80 if it did
that". $host is "the hostname part of that, apart from a couple of
exceptions". If you're not sure which to use, use $host.

"redirect" usually suggests "send a http 301 to the browser, so that
it issues a new request". That's not what you want to happen. Perhaps
$landing_page would be clearer for the next person to read? But that's
not directly relevant to the configuration issue.

> hostnames;
>
> default notset;
>
> .example1.com /link/example1;

When you have many things in the one server block, consistency is great.

"notset" is a flag which means "do something special".

What is "/link/example1"? A file that should be served? A file that
should be php-processed? A directory containing a file that should be
php-processed?

Maybe something like

  default /index.php;
  .example1.com /link/example1/index.php;

would allow you to handle all situations equivalently.

> }
>
> hostname example.com;
>
> location = / {
> if ( $page_redirect ~ notset ) {
> rewrite ^ /index.php break;
> }

location -> if -> "return ..." is OK.
location -> if -> "rewrite ... last" is OK.
location -> if -> anything else, and you're on your own. It's 
consistent,
but not necessarily easily predictable what will happen.

> # this one works but rewrites the url.
> rewrite ^ $page_redirect redirect;

Yes - "redirect" means "rewrite the url".

> #try_files $page_redirect $page_redirect/ /index.php?$page_redirect;
> }
>
> So I'm basically only trying to redirect from http://www.example.com for
> example, but not http://www.example.com/index.php, and only from
> predefined domains.

Given your above configuration, am I right that what you want is:

http://www.example.com/ -> php-process /usr/local/nginx/html/index.php
http://www.example.com/index.php -> php-process 
/usr/local/nginx/html/index.php
http://www.example.com/file.png -> send /usr/local/nginx/html/file.png
http://www.example1.com/ -> php-process 
/usr/local/nginx/html/link/example1/index.php
http://www.example1.com/index.php -> php-process 
/usr/local/nginx/html/index.php
http://www.example1.com/file.png -> send /usr/local/nginx/html/file.png

where in each case "send" or "php-process" means "respond http 200 with
the output of that file"?

> As the comment says, this does work if I use a rewrite ... redirect; but
> the URL then changes to http://www.example1.com/link/example1, whereas I
> want to see http://www.example1.com alone.
>
> The try_files comes up with a 404, which is really perplexing... I
> expected it to go through the .php block like the others!

After "location -> if -> anything else", I find it's usually not worth
wondering why things do or don't work as hoped. You're in "here be
dragons" territory anyway. That's nginx.

> Any ideas what I'm doing wrong?

With the assumptions and changes from above, maybe

  location = / {
    fastcgi_pass unix:php.sock;
    include fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $document_root$page_redirect;
  }

is closer to what you want?

Good luck with it,

  f
--
Francis Daly        francis@daoine.org

On Sun, 2012-12-09 at 10:29 +0000, Francis Daly wrote:

> where in each case "send" or "php-process" means "respond http 200 with
> wondering why things do or don't work as hoped. You're in "here be
>   }
>
> is closer to what you want?
>
> Good luck with it,

Thanks for the ideas Francis, it's cleaned up my config no end!

This is a WordPress site, so all requests have to go to /index.php to be
processed. The URL dictates the page returned.

I can't seem to find a way of mimicing what I'm trying to do with your
method, no matter what fastcgi_params I try setting up.

Cheers,


Steve

On Mon, 2012-12-10 at 09:51 +1300, Steve Holdoway wrote:
> On Sun, 2012-12-09 at 10:29 +0000, Francis Daly wrote:

> > Good luck with it,
>
>
> Steve
>
As with everything like this, 2 extra minutes with google found me the
answer. I need to add

fastcgi_param  PATH_INFO $page_redirect;

and it works perfectly.

Chanks for putting me on the right track,

Steve

On Mon, Dec 10, 2012 at 10:05:58AM +1300, Steve Holdoway wrote:
> On Mon, 2012-12-10 at 09:51 +1300, Steve Holdoway wrote:

Hi there,

> fastcgi_param  PATH_INFO $page_redirect;
>
> and it works perfectly.

"works perfectly" is always a good report. Glad you found what you 
wanted.

All the best,

  f
--
Francis Daly        francis@daoine.org