Subdomain Access Issue - Specific EU-Prefixed Domains Not Loading

Website, Application, Performance Getting Started
1

What is the name of the domain?

eu-app.scematics.xyz

What is the error number?

NA

What is the error message?

Loading the same page for all the docs url.

What is the issue you’re encountering

Loading the same page for all the docs url.

What steps have you taken to resolve the issue?

Attempted Troubleshooting:

Configurations appear identical
DNS, SSL, and network connectivity suspected as potential issues

Seeking community insights on potential root causes preventing access to these EU-prefixed subdomains.

What are the steps to reproduce the issue?

I’m experiencing an inconsistent access problem with similar Nginx-configured subdomains:

Working domain: FastAPI - Swagger UI
Non-functioning domains:

Both non-functioning domains:

Have identical Nginx configurations
Return the same unresponsive page
Share similar SSL and proxy settings with the working domain

2

The subdomains, that you’re mentioning, works fine from my side.

1 Like
3

Thank you for checking. To clarify, the issue isn’t that the EU-prefixed subdomains don’t load at all, but rather they’re loading incorrect content.

Specifically:

  • https://app-import.scematics.xyz/api/v1/docs loads its correct content
  • https://eu-app-import.scematics.xyz/api/v1/docs incorrectly loads content from https://eu-app.scematics.xyz/api/v1/docs

Despite having identical Nginx configurations, the EU-prefixed domains seem to be routing to a different backend than intended.

4

None of them are being cached by Cloudflare at the moment.

One very plausible cause of this, would be a simple mistake in your nginx configurations, such as e.g.:

  1. Forgetting to change the server_name directive in the new virtual host, that initially was copied from another one.

  2. Greedy server_name directive from another virtual host / server block, but nothing matching (more) specifically for eu-app-import.scematics.xyz.

  3. Setting the wrong data directory in the virtual host configuration for eu-app-import.scematics.xyz.

  4. Forgetting to reload/restart nginx, after changing it’s configuration.

As the CF-Cache-Status is DYNAMIC, the incorrect content is coming directly from the Ubuntu server, that you have behind Cloudflare.

5

I have reviewed my Nginx configurations, and they are identical across both virtual hosts. For reference, I have attached configuration snapshots to confirm that no mistakes were made.

To address the common concerns:

  • The server_name directive is correctly set for both domains.
  • There is no conflicting or greedy server_name directive in another virtual host.
  • The correct data directory is specified.
  • Nginx has been properly reloaded/restarted after applying the configurations.

Individually, all modules work fine when executed separately. However, when running everything at once using a bash script, the issue occurs.

eu-app
eu-app1920×662 181 KB

6

They seem so, yeah.

Before these snapshots, I see no mentions from your side, that you were using the reverse proxy functionality through nginx.

That adds several other views.

The “common concerns” from above, those are now common concerns for the “proxy_pass” destination, that you have running on “http://localhost:7502”, and not alone for your nginx configuration.

If they are both supposed to show different content from each other, … do you really intend to send traffic for both of them, towards “http://localhost:7502”, i.e. towards the exact same port?

Or did you intend to send one to 7502, another to 7503, … and so on?

Based on the new information (e.g. “reverse proxy”), I would now be suggesting you to look for the cause of the problem, at the the destination (or application), that you’re running on “http://localhost:7502”, as that one likely is the culprit, and giving nginx “incorrect” information, that nginx then passes on to Cloudflare.

7

Thank you for your analysis. I should clarify that I’m actually using two completely separate servers, not just one. I only shared the nginx config snapshots for reference.

To be more specific:

  • app.scematics.xyz (along with its subdomains) is hosted on one Ubuntu server
  • eu-app.scematics.xyz (with its subdomains) is hosted on an entirely different server

While both configurations use port 7502, they’re completely different environments. In Cloudflare’s DNS settings, app-import.scematics.xyz points to the IP address of the first server, while eu-app-import.scematics.xyz points to the IP address of the second server.

So even though the port numbers are the same (7502), they’re on different machines with different IP addresses. That’s why I didn’t think the port number itself would be causing any conflicts, since they’re completely separate systems.

8

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