Ah, I see the issue here—your current configuration is targeting the wrong part of the request! Let's break down what's going wrong and how to fix it.

Root Cause of the Problem #

The location directive in Nginx matches against the request URI (the path part of the URL)—not the domain name (Host header). Your regex ~ ^(?!(.?)examplesite.com/?(.*)) is checking if the path doesn't start with examplesite.com, which is true for almost every request (since paths start with /). That's why even requests to examplesite.com are hitting the 404 rule.

Correct Solutions #

Option 1: Use Separate Server Blocks (Recommended) #

This is the most idiomatic Nginx approach—split your configuration into two server blocks to handle valid domains and all others separately:

# Handle examplesite.com and all its subdomains
server {
    listen 80; # Update to 443 if using HTTPS, and add SSL cert config
    server_name examplesite.com *.examplesite.com;

    location / {
        return 302 https://192.168.1.1/index.html;
    }
}

# Default server: Return 404 for all other domains
server {
    listen 80 default_server; # Update to 443 default_server for HTTPS
    server_name _; # Matches any host not covered by other server blocks

    location / {
        return 404;
    }
}

• The first server block catches all requests to examplesite.com and any subdomain (like sub.examplesite.com), then redirects them to your local server.
• The default server block handles every other domain request and returns a 404.

Option 2: Single Server Block with Host Check #

If you need to keep everything in one server block, use an if directive to check the $host variable (which holds the domain name from the request header):

server {
    listen 80; # Adjust for HTTPS as needed
    server_name _; # Or list your actual server names here

    # Reject any request not targeting examplesite.com or its subdomains
    if ($host !~* ^(.+\.)?examplesite\.com$) {
        return 404;
    }

    # Redirect valid requests to your local server
    location / {
        return 302 https://192.168.1.1/index.html;
    }
}

• The regex ^(.+\.)?examplesite\.com$ matches examplesite.com directly, plus any subdomain (like blog.examplesite.com or app.sub.examplesite.com).
• Note: While if is generally discouraged in Nginx for complex logic, this simple host check is safe to use.

Key Takeaway #

Always remember: location blocks match the request path, not the domain. To filter by domain, use either separate server blocks or check the $host variable.

内容的提问来源于stack exchange，提问作者stefs