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-tools/pkg/crd/desc_visitor.go

@@ -0,0 +1,78 @@
+/*
+Copyright 2019 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 crd
+
+import (
+	"strings"
+	"unicode"
+
+	apiext "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
+)
+
+// TruncateDescription truncates the description of fields in given schema if it
+// exceeds maxLen.
+// It tries to chop off the description at the closest sentence boundary.
+func TruncateDescription(schema *apiext.JSONSchemaProps, maxLen int) {
+	EditSchema(schema, descVisitor{maxLen: maxLen})
+}
+
+// descVisitor recursively visits all fields in the schema and truncates the
+// description of the fields to specified maxLen.
+type descVisitor struct {
+	// maxLen is the maximum allowed length for decription of a field
+	maxLen int
+}
+
+func (v descVisitor) Visit(schema *apiext.JSONSchemaProps) SchemaVisitor {
+	if schema == nil {
+		return v
+	}
+	if v.maxLen < 0 {
+		return nil /* no further work to be done for this schema */
+	}
+	if v.maxLen == 0 {
+		schema.Description = ""
+		return v
+	}
+	if len(schema.Description) > v.maxLen {
+		schema.Description = truncateString(schema.Description, v.maxLen)
+		return v
+	}
+	return v
+}
+
+// truncateString truncates given desc string if it exceeds maxLen. It may
+// return string with length less than maxLen even in cases where original desc
+// exceeds maxLen because it tries to chop off the desc at the closest sentence
+// boundary to avoid incomplete sentences.
+func truncateString(desc string, maxLen int) string {
+	desc = desc[0:maxLen]
+
+	// Trying to chop off at closest sentence boundary.
+	if n := strings.LastIndexFunc(desc, isSentenceTerminal); n > 0 {
+		return desc[0 : n+1]
+	}
+	// TODO(droot): Improve the logic to chop off at closest word boundary
+	// or add elipses (...) to indicate that it's chopped incase no closest
+	// sentence found within maxLen.
+	return desc
+}
+
+// helper function to determine if given rune is a sentence terminal or not.
+func isSentenceTerminal(r rune) bool {
+	return unicode.Is(unicode.STerm, r)
+}