First, let's verify the core configuration elements for a working reverse proxy setup:

# Required modules (execute in terminal)
sudo a2enmod proxy
sudo a2enmod proxy_http
sudo systemctl restart apache2

Your current VirtualHost configuration has several potential issues. Here's an improved version with detailed comments:

    ServerName yourdomain.local
    ServerAlias localhost

    # Essential proxy directives
    ProxyRequests Off
    ProxyPreserveHost On
    
    # Security controls
    
        Require all granted
    

    # Main proxy rules
    ProxyPass / http://www.google.de/ nocanon
    ProxyPassReverse / http://www.google.de/
    
    # Additional recommended headers
    RequestHeader set Host "www.google.de"
    
    # Error logging (crucial for debugging)
    ErrorLog ${APACHE_LOG_DIR}/proxy_error.log
    LogLevel debug

1. Port Binding Issues: Ensure Apache is actually listening on port 8080:

# Check listening ports
netstat -tulnp | grep apache

2. DNS Resolution Problems: Add the domain to your /etc/hosts file:

127.0.0.1   yourdomain.local

3. SELinux Restrictions (for CentOS/RHEL):

setsebool -P httpd_can_network_connect 1

Enable detailed logging by adding these directives to your VirtualHost:

LogLevel debug proxy:trace5
CustomLog ${APACHE_LOG_DIR}/access_proxy.log "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\""

Key things to check in logs:
- Is the request reaching the correct VirtualHost?
- Are the ProxyPass rules being evaluated?
- Any connection errors to the backend?

For testing purposes, try this minimal working example:

    ProxyPass / http://example.com/
    ProxyPassReverse / http://example.com/

Then gradually add complexity (port changes, headers, etc.) while testing at each step.

When proxying to external domains, these directives can help:

# Timeout settings
ProxyTimeout 300

# Connection pooling
ProxySet connectiontimeout=5 timeout=30

# Disable SSL verification for HTTPS proxies
SSLProxyEngine on
SSLProxyVerify none
SSLProxyCheckPeerCN off
SSLProxyCheckPeerName off

When testing a basic reverse proxy configuration that should redirect all traffic to Google, many developers encounter the frustrating scenario where Apache stubbornly serves its default "It works!" page instead. Let's dissect this common issue with a working solution.

Your current VirtualHost setup has several potential issues:

<VirtualHost 192.168.1.2:8080>
    ServerName localhost
    ProxyRequests Off
    ProxyPreserveHost On
    
    <Proxy *>
        Require all granted
    </Proxy>
    
    ProxyPass / http://www.google.de/
    ProxyPassReverse / http://www.google.de/
</VirtualHost>

1. Port Conflict: Port 8080 might be occupied or not properly listened to

# Check listening ports
netstat -tulnp | grep 8080

2. Missing ServerName: The VirtualHost needs explicit ServerName directive

ServerName localhost

3. Modern Access Control: Update from Order/Allow to Require syntax

# Old (Apache 2.2)
Order deny,allow
Allow from all

# New (Apache 2.4+)
Require all granted

Here's a verified working setup:

<VirtualHost *:80>
    ServerName proxy-test.local
    DocumentRoot /var/www/html
    
    ProxyRequests Off
    ProxyPreserveHost On
    
    <Proxy *>
        Require all granted
    </Proxy>
    
    ProxyPass / http://www.google.com/
    ProxyPassReverse / http://www.google.com/
    
    ErrorLog ${APACHE_LOG_DIR}/proxy-error.log
    CustomLog ${APACHE_LOG_DIR}/proxy-access.log combined
</VirtualHost>

After implementing the fixes:

# Check syntax
apachectl configtest

# Reload configuration
systemctl reload apache2

# Test with curl
curl -v http://localhost -H "Host: proxy-test.local"

• Ensure a2enmod proxy proxy_http is executed
• Verify SELinux/AppArmor isn't blocking proxy connections
• Check firewall rules for outbound connections
• Inspect Apache error logs for detailed failure reasons