Optional finalizers

[dlmiddlecote]

Issue : #24

Description

Adding finalizers to resources means that resources cannot be deleted if the operator is not running. This PR makes sure that finalizers are added only when strictly necessary, i.e. when there are mandatory deletion handlers. If there are no deletion handlers registered, then no finalizers will be added, same if a deletion handler is marked as optional.

Types of Changes

What types of changes does your code introduce? Keep the ones that apply:

• New feature (non-breaking change which adds functionality)
• Documentation / non-code

Tasks

List of tasks you will do to complete the PR

• Add documentation

Review

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• Tests
• Documentation

[zincr]

🤖 zincr found 0 problems , 0 warnings

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✅ Dependency Licensing

[nolar]

Thanks for your PR! Here are some notes on the code itself.

The solution should work in general. Except maybe for the case with initial & CREATE detection — I have some doubts there for some cases (see comments).

I will test the functionality manually maybe in the next 1-2 days — to get the feel of how it behaves in all typical & edge cases, and if there are any "surprises" from the user point of view (though I expect none).

[dlmiddlecote]

Thank you for your review! I’ll get onto making the changes ASAP.

[nolar]

@dlmiddlecote Just for information regarding delay: All is okay with this PR. I will merge it a bit later. There is a little issue in the master branch (merged, but not released yet), which I would like to fix and release as a separate version without any intermediate merges; and also to keep the releases' deltas small.