Apache

Blocking cross sitem access to images

If you don't like that other sites link to your images, then you can use this trick:

        RewriteEngine On
        RewriteCond %{REQUEST_FILENAME} \.(jpe?g|gif|png)$ [NC]
        RewriteCond %{HTTP:Referer} !=""
        RewriteCond %{HTTP_HOST}:%{HTTP:Referer} !^([^:]*):https?://\1/.* [NC]
        RewriteRule . - [G]

This looks at requests for jpg, jpeg, gif & png, if a referer header is not empty (direct linking is ok), and the host of the request is not the host in the referer, send an "410 Gone" response.

Creating a web overlay

This is very usefull if you want to edit the CSS or JavaScript of some site. You simply start Apache2 as a proxy, that sends a local file if it exists, otherwise fetches the remote version.

Listen 127.0.0.1:8080

<VirtualHost 127.0.0.1:8080>
  UseCanonicalName Off

  ProxyRequests On

  RewriteEngine On

  DocumentRoot /home/user/proxy-htdocs/

  RewriteCond %{REQUEST_URI} ^http://([^\?]*/[^\?]*)(.*)
  RewriteCond %{DOCUMENT_ROOT}/%1/index.html -f
  RewriteRule . %{DOCUMENT_ROOT}/%1/index.html [L]

  RewriteCond %{REQUEST_URI} ^http://([^\?]*/[^\?]*)(.*)
  RewriteCond %{DOCUMENT_ROOT}/%1%2 -f
  RewriteRule . %{DOCUMENT_ROOT}/%1%2 [L]

  RewriteCond %{REQUEST_URI} ^http://([^\?]*/[^\?]*)(.*)
  RewriteCond %{DOCUMENT_ROOT}/%1 -f
  RewriteRule . %{DOCUMENT_ROOT}/%1%2 [L]

  AddDefaultCharset Off

  <Directory /home/user/proxy-htdocs/>
    Options Indexes FollowSymLinks
    AllowOverride None
    Order Deny,Allow
    Allow from all
  </Directory>

  <Proxy *>
    AddDefaultCharset off
    Order Deny,Allow
    Allow from all
  </Proxy>

  CustomLog /var/log/apache2/proxy.log combined
</VirtualHost>

In this case the url "http://bogeskov.dk/" would have the content of "/home/user/proxy-htdocs/bogeskov.dk/index.html" and "http://bogeskov.dk/tree/tree.js" would be from "/home/user/proxy-htdocs/bogeskov.dk/tree/tree.js". Then you can test your style sheet against your real site, before uploading it to for the world to see.