Resource factories

[scothis]

The resource factories used by reconciler test suites were created as a way to reduce the boiler plate for resources under test. These factories served their purpose, but suffer from a couple flaws:

1. it's too hard to create a factory for a new type
2. the provided factories cover a minimal subset of the k8s api (see 1)

I'd like to deprecate the existing factories in favor of encouraging users to define resources how they see fit. For example, https://github.com/scothis/dies follows in the spirit of reconciler runtime's factories while seeking to provide support for all common built-it k8s resources, and provides tools for generating wrappers for new types.

This migration should be broken down into a series of steps:

1. mark the existing factories as deprecated
2. update consumers of the rtesting.Factory interface to use runtime.Object (or client.Object if needed)
3. (optional) update existing factories to implement runtime.Object to make them compatible
4. release these changes
5. ...
6. remove the factories

Inside the reconciler runtime test harnesses, any bare use of a runtime.Object resource should always call .DeepCopyObject() to unwrap a factory type (if any). We largely already do this to avoid accidental mutation between test cases and to unwrap the existing factory types.

The immediate impact to most users would be that they'd need to update the test cases from defending []rtesting.Factory to []runtime.Object. Creators of custom type would need update them to implement runtime.Object or call .CreateObject() on each factory to convert the factory type to a runtime.Object.

The longer impact is that consumers of the factory types would either need to fork the types into their own repo, or convert to a different factory type (like https://github.com/scothis/dies)

[scothis]

cc @edwardecook @jhvhs @shashwathi @gmrodgers @Samze who have contributed to this package

[scothis]

Steps 1, 2 and 3 are now implemented. I ended up going with client.Object and made each of the existing factories implement the Object interface so they can continue to be used without breaking.

Users will need to update their test suite types from rtesting.Factory -> client.Object, like in this file 995d17a#diff-8ec33940c40b0250a55ef72716ce41d7cb95b8f752edf9e3b44cae90404ddd2e

Leaving this issue open until we remove the factory types in a later release

[scothis]

The factories were removed in #175