code:

    Alias /railsapp /path/to/rails/app/public
    <Directory /path/to/rails/app/public>
        RewriteEngine On
        RewriteBase /railsapp
        RewriteRule ^$ index.html [QSA]
        RewriteRule ^([^.]+)$ $1.html [QSA]
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteRule ^(.*)$ [url]http://127.0.0.1:8000/[/url]$1 [QSA,P]
        ProxyPassReverse [url]http://127.0.0.1:8000[/url]
    </Directory>
    <Proxy *>
        Order deny,allow
        Allow from all
    </Proxy>