Debian Linux
The Debian Linux distribution is a community based project. It provides a full fledged Linux distribution. It mainly consist of an enormous collection of packages and an installer. The packages are built according to a Policy. This policy describes in depth how packages are expected to behave. The strict policies do very much help in building an administration tool like this. The dependency on these policies are the reason why only Debian based distributions are supported for now.
APT integration
APT is the second layer of the Debian package tool stack. It implements what most Debian users love: the ability to install a package by a simple apt-get install PACKAGE. IsiSetup hooks into APT to enhance this mechanism by automatically importing the requested package's configuration.
Debconf integration
As Debian uses Debconf to handle some config files it is sometimes necessary to set Debconf keys to reflect changes brought in by a config file patch. This can be done using debconf snipplets in isisetup/debconf.d.
These snipplets should be run only if no local changes are detected. Currently they are run on every isisetup run, but should only run once, on the initial snipplets install.
Policies
Debian has gone far to provide the developer with nice tools to follow the policies.
There has already been done lots of work to tackle the problems I stated above. The Debian Developers are a notable part of this. The Debian System today provides
Package Repositories. http://www.us.debian.org/doc/developers-reference/ch-resources.en.html#s-archive
Maintainer scripts. http://www.us.debian.org/doc/developers-reference/ch-best-pkging-practices.en.html#s-bpp-debian-maint-scripts
- Default configuration
Debconf http://www.us.debian.org/doc/developers-reference/ch-best-pkging-practices.en.html#s-bpp-config-mgmt
Configuration File Handling http://www.us.debian.org/doc/debian-policy/ch-files.html#s-config-files
- Debian Installer
Debian packages
These are easy to install packages of software. Scripts take care of any package installation or deinstallation setup which isn't handled merely by the creation or removal of files and directories.
Debconf is a configuration management system which can be used by all the various packaging scripts (postinst mainly) to request feedback from the user concerning how to configure the package.
Configuration files stay untouched when they have been modified localy. In a normal apt-get update, the administrator would be prompted if both the packaged and local config have been changed. This is disabled by default when using IsiSetup. We use DEBIAN_FRONTEND=noninteractive and a custom apt.conf file to make package updates fully noninteractive.
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