Although it is publicly reported as working as so, in http://doc.ez.no/eZ-Publish/Technical-manual/4.x/Reference/Template-operators/URLs/ezurl eZ documentation pages , this behavior doesn't seem to comply with users expectations.

If one is generating content view cache, in a virtual host based installation, from the Admin Portal, the generated files will have the url pointing towards the Admin Portal site.

A suggestion would be to use SiteURL value from site.ini to define hostname

Steps to reproduce

Modify a template to include a link such as:

<a href={"atestlink"|ezurl('','full')}>test</a>

Publish an object and preview it in the Admin Portal (make sure that the template changed above is used in the preview process)
The generated cache file will present your Admin Portal hostname.