use istio client-go library instead of knative (#1661)

use istio client-go library instead of knative
bump kubernetes dependency version
change code coverage to codecov

vendor/sigs.k8s.io/controller-runtime/pkg/webhook/admission/multi.go

@@ -0,0 +1,126 @@
+/*
+Copyright 2018 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 (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"gomodules.xyz/jsonpatch/v2"
+	admissionv1beta1 "k8s.io/api/admission/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"sigs.k8s.io/controller-runtime/pkg/runtime/inject"
+)
+
+type multiMutating []Handler
+
+func (hs multiMutating) Handle(ctx context.Context, req Request) Response {
+	patches := []jsonpatch.JsonPatchOperation{}
+	for _, handler := range hs {
+		resp := handler.Handle(ctx, req)
+		if !resp.Allowed {
+			return resp
+		}
+		if resp.PatchType != nil && *resp.PatchType != admissionv1beta1.PatchTypeJSONPatch {
+			return Errored(http.StatusInternalServerError,
+				fmt.Errorf("unexpected patch type returned by the handler: %v, only allow: %v",
+					resp.PatchType, admissionv1beta1.PatchTypeJSONPatch))
+		}
+		patches = append(patches, resp.Patches...)
+	}
+	var err error
+	marshaledPatch, err := json.Marshal(patches)
+	if err != nil {
+		return Errored(http.StatusBadRequest, fmt.Errorf("error when marshaling the patch: %v", err))
+	}
+	return Response{
+		AdmissionResponse: admissionv1beta1.AdmissionResponse{
+			Allowed: true,
+			Result: &metav1.Status{
+				Code: http.StatusOK,
+			},
+			Patch:     marshaledPatch,
+			PatchType: func() *admissionv1beta1.PatchType { pt := admissionv1beta1.PatchTypeJSONPatch; return &pt }(),
+		},
+	}
+}
+
+// InjectFunc injects the field setter into the handlers.
+func (hs multiMutating) InjectFunc(f inject.Func) error {
+	// inject directly into the handlers.  It would be more correct
+	// to do this in a sync.Once in Handle (since we don't have some
+	// other start/finalize-type method), but it's more efficient to
+	// do it here, presumably.
+	for _, handler := range hs {
+		if err := f(handler); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// MultiMutatingHandler combines multiple mutating webhook handlers into a single
+// mutating webhook handler.  Handlers are called in sequential order, and the first
+// `allowed: false`	response may short-circuit the rest.  Users must take care to
+// ensure patches are disjoint.
+func MultiMutatingHandler(handlers ...Handler) Handler {
+	return multiMutating(handlers)
+}
+
+type multiValidating []Handler
+
+func (hs multiValidating) Handle(ctx context.Context, req Request) Response {
+	for _, handler := range hs {
+		resp := handler.Handle(ctx, req)
+		if !resp.Allowed {
+			return resp
+		}
+	}
+	return Response{
+		AdmissionResponse: admissionv1beta1.AdmissionResponse{
+			Allowed: true,
+			Result: &metav1.Status{
+				Code: http.StatusOK,
+			},
+		},
+	}
+}
+
+// MultiValidatingHandler combines multiple validating webhook handlers into a single
+// validating webhook handler.  Handlers are called in sequential order, and the first
+// `allowed: false`	response may short-circuit the rest.
+func MultiValidatingHandler(handlers ...Handler) Handler {
+	return multiValidating(handlers)
+}
+
+// InjectFunc injects the field setter into the handlers.
+func (hs multiValidating) InjectFunc(f inject.Func) error {
+	// inject directly into the handlers.  It would be more correct
+	// to do this in a sync.Once in Handle (since we don't have some
+	// other start/finalize-type method), but it's more efficient to
+	// do it here, presumably.
+	for _, handler := range hs {
+		if err := f(handler); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}