CentOS7+Virtualmin+Nginx环境下如何设置网站仅内网访问/离线模式？

Hey Eric, since you're using Virtualmin with Nginx on CentOS 7, here are a few reliable, straightforward ways to restrict your site to internal-only access or put it into offline mode to block external crawlers like Google:

This is the most direct approach, as it leverages Nginx's core access control capabilities:

• Log into Virtualmin, navigate to your target website, then go to Services > Configure Website > Edit Directives (this lets you edit raw Nginx config for the site).
• Inside the server block, add these rules (replace the IP ranges with your actual internal network segments, e.g., 10.0.0.0/8 for a typical private network):

  # Allow internal IPs and local loopback
  allow 192.168.0.0/24;
  allow 127.0.0.1;
  # Block all other external traffic
  deny all;
  

• Save the changes, then restart Nginx to apply them:

  sudo systemctl restart nginx
  

• Test it out: External devices should get a 403 Forbidden error, while internal devices can access the site normally.

If you want to show a friendly maintenance page to external visitors while keeping access open internally:

1. First, create a simple maintenance page (save it to your site's public directory, e.g., /home/yourdomain/public_html/maintenance.html):

   <!DOCTYPE html>
   <html>
   <head>
       <title>Site Under Maintenance</title>
       <style>body { text-align: center; margin-top: 50px; font-family: Arial; }</style>
   </head>
   <body>
       <h1>We're Performing Maintenance</h1>
       <p>Our site will be back online soon. Thank you for your patience!</p>
   </body>
   </html>
   

2. Go back to the Nginx directive editor in Virtualmin, and add these rules to the server block:

   # Allow internal IPs only
   allow 192.168.0.0/24;
   allow 127.0.0.1;
   deny all;
   
   # Serve maintenance page for blocked requests
   error_page 403 /maintenance.html;
   location = /maintenance.html {
       root /home/yourdomain/public_html;
       internal; # Prevent direct access to this page from external sources
   }
   
   # Block crawlers even if they slip through (extra layer)
   add_header X-Robots-Tag "noindex, nofollow" always;
   

3. Restart Nginx with sudo systemctl restart nginx — external visitors will see your maintenance page, and internal users get full access.

If you prefer a point-and-click interface instead of editing config files:

• In your website's Virtualmin dashboard, go to Security > Access Control.
• In the Allowed IP addresses field, add your internal network range(s) (e.g., 192.168.0.0/24) plus 127.0.0.1.
• In the Denied IP addresses field, type all to block everything else.
• Click Save — Virtualmin will automatically update the Nginx config and restart the service for you.

内容的提问来源于stack exchange，提问作者Eric