pkg/utils: add dump functions

A simple functions for pretty-printing and logging json-marshallable objects.

pkg/utils/dump.go

@@ -0,0 +1,46 @@
+/*
+Copyright 2021 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 utils
+
+import (
+	"fmt"
+	"strings"
+
+	"k8s.io/klog/v2"
+	"sigs.k8s.io/yaml"
+)
+
+func KlogDump(v klog.Level, heading, prefix string, obj interface{}) {
+	if klog.V(v).Enabled() {
+		klog.InfoDepth(1, heading)
+
+		d := strings.Split(Dump(obj), "\n")
+		// Print all but the last empty line
+		for i := 0; i < len(d)-1; i++ {
+			klog.InfoDepth(1, prefix+d[i])
+		}
+	}
+}
+
+// Dump dumps an object into YAML textual format
+func Dump(obj interface{}) string {
+	out, err := yaml.Marshal(obj)
+	if err != nil {
+		return fmt.Sprintf("<!!! FAILED TO MARSHAL %T (%v) !!!>\n", obj, err)
+	}
+	return string(out)
+}