Custom Location - Can't figoure out the headers

[OWA-dbell]

I'm working on moving over from a standalone nginx install to the NPM docker setup. I'm having trouble with a couple of hosts that need some specific headers to work. The examples below are from a LibreNMS install, but I'm seeing it on a few hosts with specific headers needed. Here is the working config from my original nginx server:

server {
        #internal server
        set $upstream 10.XX.XX.XX;

        #external URL
        server_name app.domain.com;

        #whitelist IPs allowed to connect
        allow 10.XX.XX.XX;
        deny all;

        proxy_redirect off;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Proto "https";

        location / {
                proxy_pass http://$upstream:3300;
        }

    listen [::]:443 ssl; # managed by Certbot
    listen 443 ssl; # managed by Certbot
    ...cert file info...
	include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

}

That works just fine. I added the host to NPM and I get a 502 when I try to access it. So I set a custom location of / and tried to apply my settings there:

location: /
Scheme: http
Forward IP: 10.XX.XX.XX
Forward Port: 3300

settings:
proxy_redirect off;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-Proto "https";

But I still get 502. When looking at the generated config file, I see some of the headers I set in the custom location are overwritten by some default values:

location / {
    proxy_redirect off;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-Proto "https";

    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-Scheme $scheme;
    proxy_set_header X-Forwarded-Proto  $scheme;
    proxy_set_header X-Forwarded-For    $remote_addr;
    proxy_set_header X-Real-IP          $remote_addr;
    proxy_pass       http://10.XX.XX.XX:3300;
    ....

I see a couple of the headers I set are being set just below my custom settings with the default values. But even after manually deleting those and restarting, I get the 502 errors.

Any suggestions on getting it working through NPM given the original nginx config works?

[OWA-dbell]

ran across something just after posting this. I seem to have a network issue in docker that I need to address before I mess with this. So I'm closing the discussion for now.