Merge pull request #63165 from deads2k/api-08-kubeapiversion

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Remove KUBE_API_VERSIONS

Fixes https://github.com/kubernetes/kubernetes/issues/63102

KUBE_API_VERSIONS is an attempt to control the available serialization of types. It pre-dates the idea that we'll have separate schemes, so it's not a thing that makes sense anymore.

Server-side we've had a very clear message about breaks in the logs for a year "KUBE_API_VERSIONS is only for testing. Things will break.".

Client-side it became progressively more broken as we moved to generic types for CRUD more than a year ago. What is registered doesn't matter when everything is unstructured.

We should remove this piece of legacy since it doesn't behave predictable server-side or client-side.

@smarterclayton @lavalamp
@kubernetes/sig-api-machinery-bugs 

```release-note
KUBE_API_VERSIONS is no longer respected.  It was used for testing, but runtime-config is the proper flag to set.
```

plugin/pkg/admission/eventratelimit/config.go

@@ -20,7 +20,6 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
-	"os"
 
 	"k8s.io/apimachinery/pkg/apimachinery/registered"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -31,7 +30,7 @@ import (
 )
 
 var (
-	registry = registered.NewOrDie(os.Getenv("KUBE_API_VERSIONS"))
+	registry = registered.NewAPIRegistrationManager()
 	scheme   = runtime.NewScheme()
 	codecs   = serializer.NewCodecFactory(scheme)
 )

plugin/pkg/admission/podtolerationrestriction/config.go

@@ -20,7 +20,6 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
-	"os"
 
 	"k8s.io/apimachinery/pkg/apimachinery/registered"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -32,7 +31,7 @@ import (
 )
 
 var (
-	registry = registered.NewOrDie(os.Getenv("KUBE_API_VERSIONS"))
+	registry = registered.NewAPIRegistrationManager()
 	scheme   = runtime.NewScheme()
 	codecs   = serializer.NewCodecFactory(scheme)
 )

plugin/pkg/admission/resourcequota/config.go

@@ -20,7 +20,6 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
-	"os"
 
 	"k8s.io/apimachinery/pkg/apimachinery/registered"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -31,7 +30,7 @@ import (
 )
 
 var (
-	registry = registered.NewOrDie(os.Getenv("KUBE_API_VERSIONS"))
+	registry = registered.NewAPIRegistrationManager()
 	scheme   = runtime.NewScheme()
 	codecs   = serializer.NewCodecFactory(scheme)
 )