How do I merge these two nginx rules so that it works properly?

Question

I was running Apache before using an htaccess rule but switched to nginx running a docker instance of the Discourse forum software. I am running nginx outside of the docker instance and then using proxypass so that it is located in domain.com/forum. Before I had it setup as seen below in order to take whatever subdomain is input minus www. and append it to the end of the url. If no subdomain is provided, it would just end up working as normal.

RewriteEngine on
RewriteCond %{HTTP_HOST} !^www. [NC]
RewriteCond %{HTTP_HOST} .example.com$ [NC]
RewriteRule ^(.*)$ http://example.com/forum/t/%1$1 [L,NC,QSA]

I used a converter from htaccess to nginx which gave me this:

location / {
  if ($http_host !~ "^www\."){
   rewrite ^(.*)$ http://example.com/forum/t/%1$1 redirect;
  }
}

My current location setup looks like this:

location /forum {
    proxy_pass http://unix:/var/discourse/shared/standalone/nginx.http.sock:;
    proxy_set_header Host $http_host;
    proxy_http_version 1.1;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto https;
   }
    fastcgi_read_timeout 60;
 }

So my question is, how can I merge my converted code in the if statement with my current code that contains the proxy_pass stuff? I tried to just put it in there but that just ended up with a loop.

Any insight would be appreciated, Thanks!

Answer 1

This is what I ended up with that worked. I added some additional things after the fact for specific subdomains, but this was what got that actually working.

 server {
    server_name example.com www.example.com;
    listen ipaddress;

    root /home/me/public_html;
    index index.html index.htm index.php;
    access_log /var/log/virtualmin/example.com_access_log;
    error_log /var/log/virtualmin/example.com_error_log;
    fastcgi_param GATEWAY_INTERFACE CGI/1.1;
    fastcgi_param SERVER_SOFTWARE nginx;
    fastcgi_param QUERY_STRING $query_string;
    fastcgi_param REQUEST_METHOD $request_method;
    fastcgi_param CONTENT_TYPE $content_type;
    fastcgi_param CONTENT_LENGTH $content_length;
    fastcgi_param SCRIPT_FILENAME /home/me/public_html$fastcgi_script_name;
    fastcgi_param SCRIPT_NAME $fastcgi_script_name;
    fastcgi_param REQUEST_URI $request_uri;
    fastcgi_param DOCUMENT_URI $document_uri;
    fastcgi_param DOCUMENT_ROOT /home/me/public_html;
    fastcgi_param SERVER_PROTOCOL $server_protocol;
    fastcgi_param REMOTE_ADDR $remote_addr;
    fastcgi_param REMOTE_PORT $remote_port;
    fastcgi_param SERVER_ADDR $server_addr;
    fastcgi_param SERVER_PORT $server_port;
    fastcgi_param SERVER_NAME $server_name;
    fastcgi_param HTTPS $https;
    location ~ \.php$ {
        try_files $uri =404;
        fastcgi_pass unix:/var/php-nginx/15187383894597.sock/socket;
    }
    listen 443 ssl http2;  listen [::]:443 ssl http2;
    ssl_certificate /home/me/ssl.combined;
    ssl_certificate_key /home/me/ssl.key;
        http2_idle_timeout 5m; # up from 3m default

    location /forum {

        proxy_pass http://unix:/var/discourse/shared/standalone/nginx.http.sock:;
        proxy_set_header Host $http_host;
        proxy_http_version 1.1;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto https;
    }
    fastcgi_read_timeout 60;
}

 # This server forwards requests from subdomains
 server {
  server_name ~^(.*)\.example\.com$;
   listen   ipaddress default_server;

  location / {
    return 301 https://example.com/forum/c/$1;
  }
}

Then I added a few of these to test the random specific ones, they worked just fine.

 # Test for specificsub
 server {
  server_name specificsub.example.com;
   listen   ipaddress;

  location / {
    return 301 https://example.com/forum/c/assets/specificsub;
  }
}

 # Test for specificsub2
 server {
  server_name specificsub2.example.com;
   listen   ipaddress;

  location / {
    return 301 https://example.com/forum/c/assets/specificsub2;
  }
}

Answer 2

Something like this should do the job. This probably won't work exactly as is, but should give you a general strategy to develop yourself. If you want someone to do all this for you and test it you should hire yourself a consultant.

I assume you have an unlimited set of subdomains.

// This server serves only forum traffic on the main domain
server {
  server_name example.com;

  location /forum {
      proxy_pass http://unix:/var/discourse/shared/standalone/nginx.http.sock:;
      proxy_set_header Host $http_host;
      // etc
   }

   // This should forward all requests to the forum subfolder
   location / {
     return 301 http://example.com/forum/;
   }

   // Insert any other required locations
 }

 // This server forwards requests from subdomains
 server {
  server_name ~^(.*)\.example\.com$;
  // If the line above doesn't work uncomment these two and try them instead. They basically listen to everything not specified explicitly.
  // listen       80  default_server;
  // server_name  _;

  location / {
    return 301 http://example.com/forum/t/$1;
  }
}