Automatic merge from submit-queue
Remove null -> [] slice hack
Closes#44593
When 1.6 added protobuf storage, the storage layer lost the ability to persist slice fields with empty but non-null values.
As a workaround, we tried to convert empty slice fields to `[]`, rather than `null`. Compressing `null` -> `[]` was just as much of an API breakage as `[]` -> `null`, but was hoped to cause fewer problems in clients that don't do null checks.
Because of conversion optimizations around converting lists of objects, the `null` -> `[]` hack was discovered to only apply to individual get requests, not to a list of objects. 1.6 and 1.7 was released with this behavior, and the world didn't explode. 1.7 documented the breaking API change that `null` and `[]` should be considered equivalent, unless otherwise noted on a particular field.
This PR:
* Reverts the earlier attempt (https://github.com/kubernetes/kubernetes/pull/43422) at ensuring non-null json slice output in conversion
* Makes results of `get` consistent with the results of `list` (which helps naive clients that do deepequal comparisons of objects obtained via list/watch and get), and allows empty slice fields to be returned as `null`
```release-note
Protobuf serialization does not distinguish between `[]` and `null`.
API fields previously capable of storing and returning either `[]` and `null` via JSON API requests (for example, the Endpoints `subsets` field) can now store only `null` when created using the protobuf content-type or stored in etcd using protobuf serialization (the default in 1.6+). JSON API clients should tolerate `null` values for such fields, and treat `null` and `[]` as equivalent in meaning unless specifically documented otherwise for a particular field.
```
Automatic merge from submit-queue (batch tested with PRs 45346, 45903, 45958, 46042, 45975)
ResourceQuota admission control injects registry
**What this PR does / why we need it**:
The `ResourceQuota` admission controller works with a registry that maps a GroupKind to an Evaluator. The registry used in the existing plug-in is not injectable, which makes usage of the ResourceQuota plug-in in other API server contexts difficult. This PR updates the code to support late injection of the registry via a plug-in initializer.
this is a two stage refactor when done there will be no init block in admission plugins.
Instead all plugins expose Register function which accept admission.Plugins instance.
The registration to global plugin registry happens inside Register func.
Automatic merge from submit-queue
Prepare for move zz_generated_deepcopy.go to k8s.io/api
This is in preparation to move deep copies to with the types to the types repo (see https://github.com/kubernetes/gengo/pull/47#issuecomment-296855818). The init() function is referring the `SchemeBuilder` defined in the register.go in the same packge, so we need to revert the dependency.
This PR depends on https://github.com/kubernetes/gengo/pull/49, otherwise verification will fail.
Automatic merge from submit-queue (batch tested with PRs 44862, 42241, 42101, 43181, 44147)
Update limitedByDefault() which does not return error
The limitedByDefault() just get the set of resources names, no error.
Automatic merge from submit-queue
Non global admission plugin registry
For testing the global state is a problem. This PR turns the actual registry into a struct that must be instantiated. For the beginning, we do this in `pkg/kubeapiserver/admission`. In some follow-up (where we hunt down all globals some day), we will move this into the genericapiserver.
The exported or public functions requires a doc comment to pass golint.
This commit has changes of conversion generated code. The actual doc
changes are added into a separate commit for a clean review.
