Early custom CRD support

Author: EraYaN

client/client.go

@@ -12,13 +12,15 @@ import (
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	unstructuredv1 "k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	vpav1 "k8s.io/autoscaler/vertical-pod-autoscaler/pkg/apis/autoscaling.k8s.io/v1"
 	"k8s.io/cli-runtime/pkg/resource"
 	"k8s.io/client-go/discovery"
 	"k8s.io/client-go/dynamic"
 	corev1client "k8s.io/client-go/kubernetes/typed/core/v1"
+	"k8s.io/client-go/scale"
 	"k8s.io/client-go/tools/pager"
 )
 
@@ -44,6 +46,7 @@ type Interface interface {
 	ListVPAResources(context.Context, ListOptions) ([]*vpav1.VerticalPodAutoscaler, error)
 	GetVPATarget(context.Context, *autoscalingv1.CrossVersionObjectReference, string) (*unstructuredv1.Unstructured, error)
 	ListDependentPods(ctx context.Context, targetMeta metav1.ObjectMeta, labelSelector string) ([]*corev1.Pod, error)
+	GetLabelSelectorFromResource(groupKind schema.GroupKind, namespace, name string) (labels.Selector, error)
 }
 
 var _ Interface = (*client)(nil)
@@ -56,6 +59,7 @@ type client struct {
 	discoveryClient discovery.DiscoveryInterface
 	coreClient      *corev1client.CoreV1Client
 	mapper          meta.RESTMapper
+	scaleNamespacer scale.ScalesGetter
 
 	// lock during lazy init of the client
 	sync.Mutex
@@ -222,6 +226,33 @@ func (c *client) ListDependentPods(ctx context.Context, targetMeta metav1.Object
 	return pods, nil
 }
 
+func (c *client) GetLabelSelectorFromResource(groupKind schema.GroupKind, namespace, name string) (labels.Selector, error) {
+	mappings, err := c.mapper.RESTMappings(groupKind)
+	if err != nil {
+		return nil, err
+	}
+
+	var lastError error
+	for _, mapping := range mappings {
+		groupResource := mapping.Resource.GroupResource()
+		scale, err := c.scaleNamespacer.Scales(namespace).Get(context.TODO(), groupResource, name, metav1.GetOptions{})
+		if err == nil {
+			if scale.Status.Selector == "" {
+				return nil, fmt.Errorf("Resource %s/%s has an empty selector for scale sub-resource", namespace, name)
+			}
+			selector, err := labels.Parse(scale.Status.Selector)
+			if err != nil {
+				return nil, err
+			}
+			return selector, nil
+		}
+		lastError = err
+	}
+
+	// nothing found, apparently the resource does not support scale (or we lack RBAC)
+	return nil, lastError
+}
+
 // referenceMatchController returns whether the given
 // OwnerReference matches a target controller.
 func referenceMatchController(ref metav1.OwnerReference, targetMeta metav1.ObjectMeta) bool {

client/flags.go

@@ -7,7 +7,9 @@ import (
 	"github.com/spf13/pflag"
 	"k8s.io/cli-runtime/pkg/genericclioptions"
 	"k8s.io/client-go/dynamic"
+	kube_client "k8s.io/client-go/kubernetes"
 	corev1client "k8s.io/client-go/kubernetes/typed/core/v1"
+	"k8s.io/client-go/scale"
 	"k8s.io/kubectl/pkg/cmd/get"
 	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	"k8s.io/kubectl/pkg/util"
@@ -107,12 +109,19 @@ func (f *Flags) NewClient() (Interface, error) {
 	if err != nil {
 		return nil, err
 	}
+	r := scale.NewDiscoveryScaleKindResolver(dis)
+
+	kubeClient := kube_client.NewForConfigOrDie(config)
+	restClient := kubeClient.CoreV1().RESTClient()
+	scaleNamespacer := scale.New(restClient, m, dynamic.LegacyAPIPathResolverFunc, r)
+
 	c := &client{
 		flags:           f,
 		dynamicClient:   dyn,
 		discoveryClient: dis,
 		coreClient:      pc,
 		mapper:          m,
+		scaleNamespacer: scaleNamespacer,
 	}
 	return c, nil
 }

vpa/target.go

@@ -11,6 +11,7 @@ import (
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	unstructuredv1 "k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 
@@ -53,35 +54,60 @@ func NewTargetController(c client.Interface, ref *autoscalingv1.CrossVersionObje
 	}
 	kind := obj.GetKind()
 
+	isWellKnown := false
+
 	switch wellKnownControllerKind(kind) {
 	case cj, ds, deploy, job, rs, rc, sts, ro:
+		isWellKnown = true
 	case node:
 		// Some pods specify nodes as their owners,
 		// but they aren't valid controllers that
 		// the VPA supports, so we just skip them.
 		return nil, fmt.Errorf("node is not a valid target")
 	default:
-		return nil, fmt.Errorf("unsupported target kind: %s", kind)
-	}
-	tc := &TargetController{
-		Name:             obj.GetName(),
-		Namespace:        obj.GetNamespace(),
-		GroupVersionKind: obj.GetObjectKind().GroupVersionKind(),
-		controllerKind:   wellKnownControllerKind(kind),
-		controllerObj:    obj,
-	}
-	tc.podSpec, err = resolvePodSpec(obj)
-	if err != nil {
-		return nil, err
+		isWellKnown = false
 	}
-	labelSelector, err := resolveLabelSelector(obj)
-	if err != nil {
-		return nil, err
-	}
-	selector, err := metav1.LabelSelectorAsSelector(labelSelector)
-	if err != nil {
-		return nil, err
+	var tc *TargetController
+	var selector labels.Selector
+
+	if isWellKnown {
+		tc = &TargetController{
+			Name:             obj.GetName(),
+			Namespace:        obj.GetNamespace(),
+			GroupVersionKind: obj.GetObjectKind().GroupVersionKind(),
+			controllerKind:   wellKnownControllerKind(kind),
+			controllerObj:    obj,
+		}
+		tc.podSpec, err = resolvePodSpec(obj)
+		if err != nil {
+			return nil, err
+		}
+
+		labelSelector, err := resolveLabelSelector(obj)
+		if err != nil {
+			return nil, err
+		}
+
+		selector, err = metav1.LabelSelectorAsSelector(labelSelector)
+		if err != nil {
+			return nil, err
+		}
+
+	} else {
+		tc = &TargetController{
+			Name:             obj.GetName(),
+			Namespace:        obj.GetNamespace(),
+			GroupVersionKind: obj.GetObjectKind().GroupVersionKind(),
+			controllerKind:   wellKnownControllerKind(kind),
+			controllerObj:    obj,
+		}
+		selector, err = c.GetLabelSelectorFromResource(tc.GroupVersionKind.GroupKind(), tc.Namespace, tc.Name)
+
+		if err != nil {
+			return nil, err
+		}
 	}
+
 	// The PodSpec template defined by a controller might not represent
 	// the final spec of the pods. For example, a LimitRanger controller
 	// could change the spec of pods to set default resource requests and
@@ -104,7 +130,7 @@ func NewTargetController(c client.Interface, ref *autoscalingv1.CrossVersionObje
 	}
 	if len(pods) != 0 {
 		p := pods[0]
-		if !reflect.DeepEqual(p.Spec.Containers, tc.podSpec.Containers) {
+		if tc.podSpec == nil || !reflect.DeepEqual(p.Spec.Containers, tc.podSpec.Containers) {
 			tc.podSpec = &p.Spec
 		}
 	}