Update to kube v1.17

Signed-off-by: Humble Chirammal <hchiramm@redhat.com>

vendor/k8s.io/apiserver/pkg/admission/handler.go

@@ -0,0 +1,79 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package admission
+
+import (
+	"time"
+
+	"k8s.io/apimachinery/pkg/util/sets"
+)
+
+const (
+	// timeToWaitForReady is the amount of time to wait to let an admission controller to be ready to satisfy a request.
+	// this is useful when admission controllers need to warm their caches before letting requests through.
+	timeToWaitForReady = 10 * time.Second
+)
+
+// ReadyFunc is a function that returns true if the admission controller is ready to handle requests.
+type ReadyFunc func() bool
+
+// Handler is a base for admission control handlers that
+// support a predefined set of operations
+type Handler struct {
+	operations sets.String
+	readyFunc  ReadyFunc
+}
+
+// Handles returns true for methods that this handler supports
+func (h *Handler) Handles(operation Operation) bool {
+	return h.operations.Has(string(operation))
+}
+
+// NewHandler creates a new base handler that handles the passed
+// in operations
+func NewHandler(ops ...Operation) *Handler {
+	operations := sets.NewString()
+	for _, op := range ops {
+		operations.Insert(string(op))
+	}
+	return &Handler{
+		operations: operations,
+	}
+}
+
+// SetReadyFunc allows late registration of a ReadyFunc to know if the handler is ready to process requests.
+func (h *Handler) SetReadyFunc(readyFunc ReadyFunc) {
+	h.readyFunc = readyFunc
+}
+
+// WaitForReady will wait for the readyFunc (if registered) to return ready, and in case of timeout, will return false.
+func (h *Handler) WaitForReady() bool {
+	// there is no ready func configured, so we return immediately
+	if h.readyFunc == nil {
+		return true
+	}
+
+	timeout := time.After(timeToWaitForReady)
+	for !h.readyFunc() {
+		select {
+		case <-time.After(100 * time.Millisecond):
+		case <-timeout:
+			return h.readyFunc()
+		}
+	}
+	return true
+}