Merge pull request #51033 from mtaufen/revert-51008-revert-50789-fix-scheme

Automatic merge from submit-queue (batch tested with PRs 50967, 50505, 50706, 51033, 51028)

Revert "Merge pull request #51008 from kubernetes/revert-50789-fix-scheme"

I'm spinning up a cluster right now to test this fix, but I'm pretty sure this was the problem.
There doesn't seem to be a way to confirm from logs, because AFAICT the logs from the hollow kubelet containers are not collected as part of the kubemark test.

**What this PR does / why we need it**:

This reverts commit f4afdecef8, reversing
changes made to e633a1604f.

This also fixes a bug where Kubemark was still using the core api scheme
to manipulate the Kubelet's types, which was the cause of the initial
revert.

**Which issue this PR fixes**: fixes #51007

**Release note**:

```release-note
NONE
```

/cc @shyamjvs @wojtek-t

cmd/kubelet/app/BUILD

@@ -41,6 +41,7 @@ go_library(
         "//pkg/features:go_default_library",
         "//pkg/kubelet:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig:go_default_library",
+        "//pkg/kubelet/apis/kubeletconfig/scheme:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig/v1alpha1:go_default_library",
         "//pkg/kubelet/cadvisor:go_default_library",
         "//pkg/kubelet/certificate:go_default_library",

cmd/kubelet/app/options/BUILD

@@ -12,11 +12,10 @@ go_library(
         "options.go",
     ],
     deps = [
-        "//pkg/api:go_default_library",
         "//pkg/apis/componentconfig:go_default_library",
         "//pkg/features:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig:go_default_library",
-        "//pkg/kubelet/apis/kubeletconfig/install:go_default_library",
+        "//pkg/kubelet/apis/kubeletconfig/scheme:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig/v1alpha1:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig/validation:go_default_library",
         "//pkg/util/taints:go_default_library",

cmd/kubelet/app/options/options.go

@@ -25,14 +25,12 @@ import (
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/apiserver/pkg/util/flag"
 	utilflag "k8s.io/apiserver/pkg/util/flag"
-	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/apis/componentconfig"
 	"k8s.io/kubernetes/pkg/features"
 	"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig"
-	kubeletconfigvalidation "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/validation"
-	// Need to make sure the kubeletconfig api is installed so defaulting funcs work
-	_ "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/install"
+	kubeletscheme "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/scheme"
 	"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/v1alpha1"
+	kubeletconfigvalidation "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/validation"
 	utiltaints "k8s.io/kubernetes/pkg/util/taints"
 
 	"github.com/spf13/pflag"
@@ -142,10 +140,14 @@ func ValidateKubeletFlags(f *KubeletFlags) error {
 
 // NewKubeletConfiguration will create a new KubeletConfiguration with default values
 func NewKubeletConfiguration() (*kubeletconfig.KubeletConfiguration, error) {
+	scheme, _, err := kubeletscheme.NewSchemeAndCodecs()
+	if err != nil {
+		return nil, err
+	}
 	versioned := &v1alpha1.KubeletConfiguration{}
-	api.Scheme.Default(versioned)
+	scheme.Default(versioned)
 	config := &kubeletconfig.KubeletConfiguration{}
-	if err := api.Scheme.Convert(versioned, config, nil); err != nil {
+	if err := scheme.Convert(versioned, config, nil); err != nil {
 		return nil, err
 	}
 	return config, nil

cmd/kubelet/app/server.go

@@ -60,6 +60,7 @@ import (
 	"k8s.io/kubernetes/pkg/features"
 	"k8s.io/kubernetes/pkg/kubelet"
 	kubeletconfiginternal "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig"
+	kubeletscheme "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/scheme"
 	kubeletconfigv1alpha1 "k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig/v1alpha1"
 	"k8s.io/kubernetes/pkg/kubelet/cadvisor"
 	"k8s.io/kubernetes/pkg/kubelet/certificate"
@@ -188,20 +189,30 @@ func checkPermissions() error {
 	return nil
 }
 
-func setConfigz(cz *configz.Config, kc *kubeletconfiginternal.KubeletConfiguration) {
-	tmp := kubeletconfigv1alpha1.KubeletConfiguration{}
-	api.Scheme.Convert(kc, &tmp, nil)
-	cz.Set(tmp)
+func setConfigz(cz *configz.Config, kc *kubeletconfiginternal.KubeletConfiguration) error {
+	scheme, _, err := kubeletscheme.NewSchemeAndCodecs()
+	if err != nil {
+		return err
+	}
+	versioned := kubeletconfigv1alpha1.KubeletConfiguration{}
+	if err := scheme.Convert(kc, &versioned, nil); err != nil {
+		return err
+	}
+	cz.Set(versioned)
+	return nil
 }
 
-func initConfigz(kc *kubeletconfiginternal.KubeletConfiguration) (*configz.Config, error) {
+func initConfigz(kc *kubeletconfiginternal.KubeletConfiguration) error {
 	cz, err := configz.New("kubeletconfig")
-	if err == nil {
-		setConfigz(cz, kc)
-	} else {
+	if err != nil {
 		glog.Errorf("unable to register configz: %s", err)
+		return err
 	}
-	return cz, err
+	if err := setConfigz(cz, kc); err != nil {
+		glog.Errorf("unable to register config: %s", err)
+		return err
+	}
+	return nil
 }
 
 // makeEventRecorder sets up kubeDeps.Recorder if its nil. Its a no-op otherwise.
@@ -250,7 +261,7 @@ func run(s *options.KubeletServer, kubeDeps *kubelet.Dependencies) (err error) {
 	}
 
 	// Register current configuration with /configz endpoint
-	_, err = initConfigz(&s.KubeletConfiguration)
+	err = initConfigz(&s.KubeletConfiguration)
 	if err != nil {
 		glog.Errorf("unable to register KubeletConfiguration with configz, error: %v", err)
 	}
@@ -756,7 +767,8 @@ func parseResourceList(m kubeletconfiginternal.ConfigurationMap) (v1.ResourceLis
 }
 
 // BootstrapKubeletConfigController constructs and bootstrap a configuration controller
-func BootstrapKubeletConfigController(flags *options.KubeletFlags,
+func BootstrapKubeletConfigController(
+	flags *options.KubeletFlags,
 	defaultConfig *kubeletconfiginternal.KubeletConfiguration) (*kubeletconfiginternal.KubeletConfiguration, *kubeletconfig.Controller, error) {
 	var err error
 	// Alpha Dynamic Configuration Implementation; this section only loads config from disk, it does not contact the API server
@@ -777,7 +789,10 @@ func BootstrapKubeletConfigController(flags *options.KubeletFlags,
 	}
 
 	// get the latest KubeletConfiguration checkpoint from disk, or load the init or default config if no valid checkpoints exist
-	kubeletConfigController := kubeletconfig.NewController(initConfigDir, dynamicConfigDir, defaultConfig)
+	kubeletConfigController, err := kubeletconfig.NewController(initConfigDir, dynamicConfigDir, defaultConfig)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to construct controller, error: %v", err)
+	}
 	kubeletConfig, err := kubeletConfigController.Bootstrap()
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed to determine a valid configuration, error: %v", err)

cmd/kubelet/kubelet.go

@@ -89,7 +89,10 @@ func main() {
 	}
 
 	// construct a KubeletServer from kubeletFlags and kubeletConfig
-	kubeletServer := &options.KubeletServer{KubeletFlags: *kubeletFlags, KubeletConfiguration: *kubeletConfig}
+	kubeletServer := &options.KubeletServer{
+		KubeletFlags:         *kubeletFlags,
+		KubeletConfiguration: *kubeletConfig,
+	}
 
 	// use kubeletServer to construct the default KubeletDeps
 	kubeletDeps, err := app.UnsecuredDependencies(kubeletServer)