De/restructure objects via JSON

[guicassolato]

I've been having issues with using the default Kubernetes API Machinery converter to restruct/destruct objects based on types that contain embedded fields. In particular, converting objects of such kinds often result in data loss.

This is an attempt to workaround those issues by converting via JSON. Although, theoretically more expensive, I hope this can prevent at least the data loss, which is definitely the most concerning problem.

[guicassolato]

I've tested this with Kuadrant/kuadrant-operator#952 and it works!

This will fix conversion of nested fields such as https://github.com/Kuadrant/authorino/blob/8e530e5593a123a70fce3e815a9228b17f707651/api/v1beta3/auth_config_types.go#L261.

Probably, we'll no longer have to implement custom unmarshallers like this one either:

policy-machinery/examples/kuadrant/apis/v1beta3/authpolicy_types.go

Lines 268 to 270 in ec853f9

	// UnmarshalJSON unmarshals the AuthPolicySpec from JSON byte array.
	// This should not be needed, but runtime.DefaultUnstructuredConverter.FromUnstructured does not work well with embedded structs.
	func (s *AuthPolicySpec) UnmarshalJSON(j []byte) error {

[KevFan]

Looks good to me! 💯