In my quest to get a better understanding of reactive programming I created a little app that has two endpoints a POST and a GET. The POST method saves some data to MongoDB Atlas and the GET method returns the data from the DB.

The workflow: GET Request via a browser --> POST some new data via curl --> the new data gets displayed in the browser.

The workflow works locally but as soon as I add NGINX in the mix the workflow stops working. No data is displayed and the connection is being terminated after some time.

My Controller:

    @GetMapping(value = "mda", produces = MediaType.APPLICATION_STREAM_JSON_VALUE)
    public Flux<ResponseData> getAll(){
        return repo.findBy();
    }

My repo method:

   @Tailable
   Flux<ResponseData> findBy();

How must I change my NGINX conf to make the app work?

My NGINX Config. I changed the original domain:

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

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

    location /reactive/data {
        proxy_pass http://localhost:8081/data;
        proxy_redirect off;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto https;
    }

    location /reactive/mda {
        proxy_pass http://localhost:8081/mda;
        proxy_redirect off;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto https;

        }   

    listen [::]:443 ssl; # managed by Certbot
    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

}
server {
    if ($host = www.example.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


    if ($host = example.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


    listen 80;
    listen [::]:80;
    server_name example.com www.example.com;
    return 404; # managed by Certbot
}

For completion: The /data endpoint contains the POST and GET (NO @Tailable) and they both work with and without NGINX.