Nginx reverse proxy only specific sub directory and pass through everything else

I have development situation where i have a domain with multiple services:

https://somewebpage.com

On this service there are multiple project as subdirectories

• https://somewebpage.com <- landing page
• https://somewebpage.com/api <- rest api server
• https://somewebpage.com/app <- my app

So is it possible (and how) to setup nginx and hosts file to reverse proxy only https://somewebpage.com/app to my local build http://localhost:3000?

The issue is that when app is deployed is has no issues accessing /api rest server but when serving locally my nginx reverse proxy intercepts landing page and rest api server urls as well.

My nginx configuration looks like:

worker_processes  1;

events {
    worker_connections  1024;
}

http {
    include       mime.types;
    default_type  application/octet-stream;

    sendfile        on;
    
    keepalive_timeout  65;
    
    index index.html;

    proxy_max_temp_file_size 0;
    proxy_buffering off;

    server {
        listen 80;
        server_name somewebpage.com;

        location / {
            return 301 https://$host$request_uri;
        }
    }

    server {
        listen 443 ssl;
        server_name somewebpage.com;

        ssl_certificate /etc/ssl/certs/certificate.crt;
        ssl_certificate_key /etc/ssl/certs/ccertificate.key;

        ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
        ssl_prefer_server_ciphers on;
        ssl_ciphers 'EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH';

        location /app {
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
            proxy_set_header Host $host;
            proxy_pass http://localhost:3000;
        }
    }
}

And in my /etc/hosts i have:

127.0.0.1    somewebpage.com

Are there any other tricks on how to achieve similar result?

The reason why i try to do this is that if i do it from my localhost:3000 it will respond with CORS errors and reject my calls to /api.

Or is this too much of security hazard and i have to ask for other way of access to /api?

Thanks for your answers in advance.

You need to add the following:

location / {
    try_files $uri $uri/ =404;
}

This tells nginx how to handle requests that don't match the other specified location. For more information how nginx selects location block to use, read nginx documentation.