mirror of https://github.com/kubernetes/kops.git
				
				
				
			
		
			
				
	
	
		
			122 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Go
		
	
	
	
			
		
		
	
	
			122 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Go
		
	
	
	
| /*
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| Copyright 2019 The Kubernetes Authors.
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| 
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| Licensed under the Apache License, Version 2.0 (the "License");
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| you may not use this file except in compliance with the License.
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| You may obtain a copy of the License at
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| 
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|     http://www.apache.org/licenses/LICENSE-2.0
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| 
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| Unless required by applicable law or agreed to in writing, software
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| distributed under the License is distributed on an "AS IS" BASIS,
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| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| See the License for the specific language governing permissions and
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| limitations under the License.
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| */
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| 
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| package reflectutils
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| 
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| import (
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| 	"bytes"
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| 	"fmt"
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| 	"reflect"
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| 
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| 	"k8s.io/klog/v2"
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| 
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| 	"k8s.io/kops/pkg/values"
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| )
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| 
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| // Printer is a custom printer function, so we can add special display for objects
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| // (without introducing a package dependency)
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| type Printer func(o interface{}) (string, bool)
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| 
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| var printers []Printer
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| 
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| // RegisterPrinter adds a custom printer function
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| func RegisterPrinter(p Printer) {
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| 	printers = append(printers, p)
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| }
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| 
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| // ValueAsString returns a human-readable string representation of the passed value
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| func ValueAsString(value reflect.Value) string {
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| 	b := &bytes.Buffer{}
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| 
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| 	walker := func(path *FieldPath, field *reflect.StructField, v reflect.Value) error {
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| 		if IsPrimitiveValue(v) || v.Kind() == reflect.String {
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| 			fmt.Fprintf(b, "%v", v.Interface())
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| 			return SkipReflection
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| 		}
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| 
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| 		switch v.Kind() {
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| 		case reflect.Ptr, reflect.Interface, reflect.Slice, reflect.Map:
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| 			if v.IsNil() {
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| 				fmt.Fprintf(b, "<nil>")
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| 				return SkipReflection
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| 			}
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| 		}
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| 
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| 		switch v.Kind() {
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| 		case reflect.Ptr, reflect.Interface:
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| 			return nil // descend into value
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| 
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| 		case reflect.Slice:
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| 			len := v.Len()
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| 			fmt.Fprintf(b, "[")
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| 			for i := 0; i < len; i++ {
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| 				av := v.Index(i)
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| 
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| 				if i != 0 {
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| 					fmt.Fprintf(b, ", ")
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| 				}
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| 				fmt.Fprintf(b, "%s", ValueAsString(av))
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| 			}
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| 			fmt.Fprintf(b, "]")
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| 			return SkipReflection
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| 
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| 		case reflect.Map:
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| 			keys := v.MapKeys()
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| 			fmt.Fprintf(b, "{")
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| 			for i, key := range keys {
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| 				mv := v.MapIndex(key)
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| 
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| 				if i != 0 {
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| 					fmt.Fprintf(b, ", ")
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| 				}
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| 				fmt.Fprintf(b, "%s: %s", ValueAsString(key), ValueAsString(mv))
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| 			}
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| 			fmt.Fprintf(b, "}")
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| 			return SkipReflection
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| 
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| 		case reflect.Struct:
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| 			intf := v.Addr().Interface()
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| 
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| 			done := false
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| 			for _, p := range printers {
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| 				s, ok := p(intf)
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| 				if ok {
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| 					fmt.Fprintf(b, "%s", s)
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| 					done = true
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| 					break
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| 				}
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| 			}
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| 
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| 			if !done {
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| 				klog.V(4).Infof("Unhandled kind in asString for %q: %T", path, v.Interface())
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| 				fmt.Fprint(b, values.DebugAsJSONString(intf))
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| 			}
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| 
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| 			return SkipReflection
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| 
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| 		default:
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| 			klog.Infof("Unhandled kind in asString for %q: %T", path, v.Interface())
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| 			return fmt.Errorf("Unhandled kind for %q: %v", path, v.Kind())
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| 		}
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| 	}
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| 
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| 	err := ReflectRecursive(value, walker, &ReflectOptions{DeprecatedDoubleVisit: true})
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| 	if err != nil {
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| 		klog.Fatalf("unexpected error during reflective walk: %v", err)
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| 	}
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| 	return b.String()
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| }
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