libvmifact

libvmifact is a VMI manifest factory.

Overview

Motivation

While reading code, especially test code, a difficulty has been observed to understand in an easy and clear manner, what is the content of a VMI object. In a long chain of function call stack, different portions of the VMI got updated, sometime overriding previously set fields.

Goal

Simplify the creation of VMI objects.
Easily understand what VMI objects contain.

How

libvmifact is aimed to build the vmi manifest with a predefined set of settings that are commonly used by the e2e tests.

It uses the libvmi package, allowing a modular construction of VMI different sections.

Rules

In order to keep the package useful and easy to maintain, a few rules are in order.

The main goal of these rules are to keep the package simple to use and easy to grow. While exceptions may apply, they will need a wide consensus and should not be overused. It would be better to just ask to change the rules.

Do not add logic in factories, unless they fell into these categories:
- It is a factory that is widely used. (e.g. amount of memory depending on the architecture).
- It is a widely used abstraction that combines several fields that have some dependency on each other.
Do not add commands on objects, e.g. calls through clients.

Note: A factory is considered widely used when it is needed from multiple packages. In case a single package or test file is using it, it may fit better under that package or test. The reason is simple, it has more context closer to the usage and known by the developers in a more accurate manner.

Structure

Factory: factory.go file contains commonly used base VMI specs. Users will usually pick one factory to use and then add different builders to continue building the spec.

Maintenance and Ownership

Maintainers are expected to follow the above rules or ask for exceptions. Possibly asking to change a rule with a good reasoning.

Make sure to always keep things in focus, simple and clean. When things get out of control, things get slower, not faster.

# README