Kernel Hack


You might have heard the term hack or kernel hack used by other users of eZ Publish. Well what is a kernel hack in eZ Publish?


An eZ Publish 'Hack' or 'Kernel Hack' is considered any modification to any files or directories outside of the following directories.

  • settings/override/
  • settings/siteaccess/
  • extension/
  • var/ *

Meaning and meant as a general rule as long as you keep your modification to eZ Publish within the above directories; Inside these directories is acceptable and not a hack. Anything within the 'extension' directory is considered an extension, separate and not a hack; even if you don't activate it or use it like a traditional extension.

* Note: 'var/', modifications are allowed and often required. eZ Publish Packages relies on storing package contents within the var/ directory. For example, eZ Publish Site Design Packages, relies storing package contents like css in the var/ directory for design modifications.

Example Directories

  • bin
  • cronjobs
  • design
  • doc
  • kernel
  • lib
  • packages
  • share
  • support
  • update


I'm sure there are extensions to these general rules and guidelines. This document is a guide not an absolute.

Patch extensions

Extensions which contain kernel patches where required to impliment a feature that must be added to the kernel. This is rare that most people need to do this but it is known to exist.