Introduction to Packaging Wizard

This document describes basic usage and principles of Packaging Wizard.

Packaging Wizard (PWIZ) is a project of a software wizard, which guides through whole packaging process. It is intended for both experienced and inexperienced users.

Main goals of Packaging Wizard (PWIZ)

Packaging is a work, which combines very sophisticated and mechanical tasks. Most of those mechanical tasks can be fully automated. To make a package, you need to perform both types of actions.

This is a purpose of PWIZ. Like other wizards, it helps user to undertake through this process. If PWIZ finds a mechanical actions, then it performs it, if it finds need for qualified action, it asks human.

PWIZ is an application, which should help to create genuine quality packages by users or package maintainers with minimal manual intervention.

Understanding the PWIZ

PWIZ splits its work to phases. Each phase corresponds to some steps of work (searching for package, downloading it, inspecting sources, compiling, installing, merging to system etc.). Phases are splitted to particular stages of work. One stage is one or more commands executed at once (for PWIZ it is atomic operation, which can either fail or succeed).

PWIZ has a modular conception. PWIZ core engine core consist of phase processor and guess evaluator. Both do nothing interesting for user without modules.

One type of modular engines are intended for communication with user. Other modular engines can communicate as back-end with packaging system or package database.

The most interesting are packaging wizard modules. Those modules have chance to add its own actions to any phase, call other engines and functions from other modules. These actions are executed in its natural order. Each module handles one or more particular aspects of packaging process.

All modules alltogether with user feedback can give complete packaging process. PWIZ goes through stages and phases, and tries to guess best, what to perform. Sometimes, it requires an user intervention. It is done by standard asking iterface.

Cache

All your answers are stored in cache. Next time PWIZ needs answer for the same question, PWIZ will take this answer in account while searching for best guess.

How to understand questions values

PWIZ tries to guess best answer. It's a rule of some fuzzy logic, and any guess has two aspects:

Credit (c): If PWIZ has some indications, that this answer is the right one, credit (credibility, guess quality) of this answer increases. Such indication can be based from a result of a credible test case or from previous answer of a human being. Each possible answer gets credit in range is 0c credits to 100c (with some special out-of-range cases). Guess, which gets best credit, is considered as default.

Importance (i): For successful completion of packaging process, correct answers for some questions are more important (e. g. where to download the package), some of answers are less important (e. g. RPM description). Importance says, whether ask user or not, if PWIZ is not sure with its guess. Importance helps to decide, which question should be answered by less experienced users. Range is 1 to 100.

Such simple heuristic does not help much in real packaging. That's why PWIZ tries to deduce an inheritance of answers to subsequent version of the same package and for the same package for other products (distributions). By default, only the same package in the same product can inherit answer, and inheritance for different versions is 80%.

How to understand aswer values

To not disturb user with trivial and already answered questions, PWIZ evaluates credit of each answer. If the credit of an answer is above credit threshold, you will not be asked again.

To get qualified credibility guess, PWIZ uses two techniques - user skills and answer quality. Final credit is about product of both values.

First is user skills. You can define your knowledge skills. Your answer will never obtain higher credit than quality of your skills. On the other side, you will not be bothered with answers, which has lower credit.

User has to decide, how sure is the answer. It can be done from command line of from user interfaace. If you are guessing, you can simly press Enter to get (probably) working package using only best guesses and you will not give any credit to these answers. On other hand, if you precisely answer each question, you can "certify" your answers by your knownledge skill credit. In this case, next time PWIZ will not ask you again, because it already has answer credible enough.