There is a major web application located on a certain Domain Example.ru, and JSON API, located on the subdomain of API.example.ru. The request to the API.example.ru/sitemap dynamically generates an XML site map file. It is necessary that the request to example.ru/sitemap.xml is redirected to this API access point. Not very experienced in setting up NGINX, so difficulties have arisen. Current config (superfluous lowered):

server {
  LISTEN 80;
  Server_Name Example.ru;

  root /home/web/example.ru/www/dist;
  index index.html;

  location = /sitemap.xml {
    proxy_pass "http://api.example.ru/sitemap";
  }

  location ~ \. {
    try_files $ Uri = 404;
  }

  location / {
    Add_header X-Frame-Options "sameorigin";

    proxy_set_header X-FORWARDED-FOR $ proxy_add_x_forwarded_for;
    Proxy_Set_Header Host $ Host;

    proxy_http_version 1.1;
    proxy_pass http: // Localhost: 3000;
    proxy_redirect off;
    proxy_read_timeout 1m;
  }
}

Server {
  LISTEN 80;
  Server_name API.example.ru;

  root /home/web/example.ru/www/api/public;
  index index.php;

  location ~ \. {
    try_files $ Uri = 404;
  }

  location / {
    try_files /index.php = 404;
    include /etc/nginx/fastcgi.conf;
    FastCGI_PASS UNIX: /Run/php/php7.3-fpm.sock;
    fastcgi_index /index.php;
  }
}

With this config, the server redirects an examplephone.ru/sitemap.xml request to a web application, therefore the web application error page is displayed.
The server initially selects the correct location (checked the contents of the contents of the Location = /Sitemap.xml block on the RETURN 200 ‘test’;), but when you processes the request comes to the same SERVER unit, and not to the second corresponding to the subdomain API. *. It now comes with $ URI = / Sitemap, so location / is naturally selected and a web application is displayed.
DNS is configured correctly, and the web application and APIs are available on those domains, which and intelligently, the local CURL request to the API.example.ru/sitemap correctly returns the site map. In general, I obviously misunderstand something in the NGINX configuration. Would be grateful for the help.

Answer 1

If I understand the problem correctly, you need to specify a Host header in the lococreen:

location = / /sitemap.xml {
  proxy_set_header host api.example.ru;
  proxy_pass "http://api.example.ru/sitemap";
}

In your config option, you indicated the address of the processed server, it was cut, but the host left from the initial request, so you hit the server again.