Package Development

This page is primarily for freetz package developers.

Persistent Package Settings

Freetz provides a package configuration framework easing implementation and allows settings to be stored persistently. Packages must provide two files to use the framework:

1. /etc/default.$package/$package.cfg — This file must contain all configuration settings as exported shell variables; each variable has to start with the capitalized package name. Example:

   export PACKAGE_VAR1='var1'
   export PACKAGE_VAR2='var2'
   

1. /usr/lib/cgi-bin/$package.cgi — This is the cgi file used for package configuration. It has to be registered via ‘modreg cgi’. For examples, have a look at some package providing a web interface page.

If this is implemented correctly, freetz takes care of saving and also restarting the service, if the package provides one.

Custom package saving mechanism

Freetz also provides a mechanism to hook into the ‘normal’ saving procedure and execute custom code or do manual saving. An example using this mechanism is the package mini_fo. This mechanism comes in quite handy if the package needs to re-create configuration files or start/stop special (non-default) services on changing the configuration. It works as follows: If a package provides a file /etc/default.$package/$package.save, it will be sourced by the saving mechanism as a shell script (but it should not have a shebang line!). The .save-script can implement any or all of the following shell functions, which are executed at some special point during the saving mechanims:

pkg_pre_save()

Executed before saving happens.

pkg_apply_save()

Executed after settings were changed, but before they are saved to flash. ATTENTION! This is not executed if there are no settings (no $package.cfg file)!

pkg_post_save()

Executed after settings were saved to flash.

pkg_pre_def()

Executed before saving happens when loading the package defaults.

pkg_apply_def()

Executed after settings were changed, but before they are saved to flash when loading the package defaults. ATTENTION! This is not executed if there are no settings (no $package.cfg file)!

pkg_post_def()

Executed after settings were saved to flash when loading the package defaults.

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