website/admin behind my reverse proxy doesn't work

[Maxim Dounin]

Hello!

On Wed, Dec 28, 2022 at 11:01:11PM +0000, Mik J via nginx wrote:

> Hello,
> I have a website hosted on a server using nginx behind a nginx 
> reverse proxy but things don't work properly.
> https://mywebsite.org => works
> https://mywebsite.org/admin => doestn't work it redirects to https://mywebsite.org
> 
> On my backend serverserver {
>         listen 80;
>         server_name mywebsite.org ;
>         index index.php;
>         root /var/www/htdocs/sites/mywebsite;...
>         location / {
>           try_files $uri $uri/ /index.php$is_args$args;
> 
>           location ~ \.php$ {
>               root           /var/www/htdocs/sites/mywebsite;
>               try_files $uri =404;
>               fastcgi_pass   unix:/run/php-fpm.mywebsite.org.sock;
>               fastcgi_split_path_info ^(.+\.php)(/.+)$;
>               fastcgi_index  index.php;
>               fastcgi_param  SCRIPT_FILENAME $document_root$fastcgi_script_name;
>               include        fastcgi_params;
>           }
>         }}
> On my reverse proxyserver {
> #    listen 80;
> #    listen [::]:80;
>     listen 443 ssl;
>     listen [::]:443 ssl;
>     server_name http://mywebsite.org;...
>     root /var/www/htdocs/mywebsite;
>     location ^~ / {
>         proxy_pass              http://10.12.255.23:80;
>         proxy_redirect          off;
>         proxy_set_header        Host    $host;
>         proxy_http_version 1.1;
>         proxy_set_header  X-Real-IP        $remote_addr;
>         proxy_set_header  X-Forwarded-Host $host;
>         proxy_set_header  X-Forwarded-For  $proxy_add_x_forwarded_for;
>         proxy_set_header        Referer         "http://mywebsite.org/";
>         proxy_pass_header Set-Cookie;
>         proxy_set_header  X-Forwarded-Proto $scheme;
>     }
> }
> 
> 
> So I can't access 
> 
> In the backend server logs I see
> [28/Dec/2022:23:54:33 +0100] "GET /admin/ HTTP/1.1" 302 5 "http://mywebsite.org/" ...
> [28/Dec/2022:23:54:33 +0100] "GET / HTTP/1.1" 499 0 "http://mywebsite.org/" ...

In your nginx configurations no redirects are returned.  
Accordingly, it looks like redirects you are seeing are returned 
by the backend's PHP code.  To find out why these are returned 
you'll probably have to look into the PHP code.

-- 
Maxim Dounin
http://mdounin.ru/