When deploying WordPress behind an AWS Elastic Load Balancer (ELB), many developers encounter infinite redirect loops when using the WordPress HTTPS plugin. The issue manifests when:

• ELB terminates SSL (port 443 → port 80)
• WordPress HTTPS plugin enforces SSL
• Apache/Nginx rewrites HTTP to HTTPS

Here's what happens in the request cycle:

1. User → HTTPS → ELB (terminates SSL) → HTTP → Server
2. Server sees HTTP (X-Forwarded-Proto: https) 
3. WordPress HTTPS plugin tries to force HTTPS
4. Redirect loop begins

Here's the proper way to configure your stack:

1. Apache Configuration

<VirtualHost *:80>
    ServerName example.com
    DocumentRoot /var/www/html

    # ELB Health Check
    RewriteRule ^/health-check$ - [L]

    # Handle HTTPS redirects properly for ELB
    RewriteEngine On
    RewriteCond %{HTTP:X-Forwarded-Proto} !https
    RewriteCond %{REQUEST_URI} !^/health-check
    RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
    
    # Standard WordPress rules
    <Directory /var/www/html>
        AllowOverride All
        Require all granted
    </Directory>
</VirtualHost>

2. WordPress HTTPS Plugin Settings

Configure these specific settings:

• Enable "Proxy" mode in plugin settings
• Set "SSL Host" to your domain (e.g., example.com)
• Enable "SSL Proxy" option
• Disable "Force SSL Admin" temporarily during setup

3. WordPress wp-config.php Tweaks

Add these lines above the "That's all" comment:

// AWS ELB HTTPS Fix
if (strpos($_SERVER['HTTP_X_FORWARDED_PROTO'], 'https') !== false) {
    $_SERVER['HTTPS'] = 'on';
}
define('FORCE_SSL_ADMIN', true);

Verify with these curl commands:

# Check redirect behavior
curl -I http://example.com

# Verify headers
curl -I -H "X-Forwarded-Proto: https" http://localhost

For those using Nginx instead of Apache:

server {
    listen 80;
    server_name example.com;

    if ($http_x_forwarded_proto != 'https') {
        return 301 https://$host$request_uri;
    }

    root /var/www/html;
    index index.php;

    location / {
        try_files $uri $uri/ /index.php?$args;
    }

    location ~ \.php$ {
        include fastcgi_params;
        fastcgi_pass unix:/run/php/php7.4-fpm.sock;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    }
}

• Not enabling "Proxy" mode in WordPress HTTPS plugin
• Forgetting to update both .htaccess and wp-config.php
• Having conflicting redirect rules in multiple places
• Not testing with both HTTP and HTTPS requests

---

When deploying WordPress behind AWS Elastic Load Balancer (ELB), many developers encounter an endless redirect loop when trying to force HTTPS connections. This occurs due to the interaction between:

• ELB's header-based protocol forwarding
• WordPress HTTPS plugins
• Apache/Nginx rewrite rules

The redirect loop happens because:

1. Browser requests https://example.com
2. ELB forwards to EC2 on port 80 (X-Forwarded-Proto: https)
3. WordPress sees HTTP (not HTTPS) because ELB terminated SSL
4. HTTPS plugin forces redirect to HTTPS
5. Repeat indefinitely

First, verify your ELB listeners:

HTTP 80 → Instance port 80
HTTPS 443 → Instance port 80

Ensure health checks pass by creating a /health endpoint that returns HTTP 200.

Replace your current rewrite rules with this optimized version:

<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{HTTP:X-Forwarded-Proto} =http
    RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
</IfModule>

For WordPress HTTPS (SSL) plugin, configure these critical settings:

1. Enable "Proxy" option
2. Set "HTTPS Host" to your domain (e.g., example.com)
3. Ensure "SSL Host Detection" is disabled
4. Whitelist your ELB's IP range

Add this to your wp-config.php before WordPress loads:

if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && 
    $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https') {
    $_SERVER['HTTPS'] = 'on';
}

For those using Nginx instead of Apache:

server {
    listen 80;
    server_name example.com;
    
    if ($http_x_forwarded_proto = "http") {
        return 301 https://$server_name$request_uri;
    }
    
    # Rest of WordPress config...
}

Check these when issues persist:

1. ELB access logs for request patterns
2. WordPress siteurl/home values in database
3. Browser developer tools (Network tab)
4. Plugin conflicts (temporarily disable all plugins)

• ✓ ELB properly forwarding X-Forwarded-Proto header
• ✓ Apache/Nginx correctly interpreting the header
• ✓ WordPress configured to respect proxy headers
• ✓ No mixed content in page resources