github.com/alex123012/deckhouse-controller-tools@v0.0.0-20230510090815-d594daf1af8c/pkg/schemapatcher/internal/yaml/convert.go (about)

     1  /*
     2  Copyright 2019 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package yaml
    18  
    19  import (
    20  	"encoding/json"
    21  	"fmt"
    22  
    23  	"gopkg.in/yaml.v3"
    24  )
    25  
    26  // ToYAML converts some object that serializes to JSON into a YAML node tree.
    27  // It's useful since it pays attention to JSON tags, unlike yaml.Unmarshal or
    28  // yaml.Node.Decode.
    29  func ToYAML(rawObj interface{}) (*yaml.Node, error) {
    30  	if rawObj == nil {
    31  		return &yaml.Node{Kind: yaml.ScalarNode, Value: "null", Tag: "!!null"}, nil
    32  	}
    33  
    34  	rawJSON, err := json.Marshal(rawObj)
    35  	if err != nil {
    36  		return nil, fmt.Errorf("failed to marshal object: %w", err)
    37  	}
    38  
    39  	var out yaml.Node
    40  	if err := yaml.Unmarshal(rawJSON, &out); err != nil {
    41  		return nil, fmt.Errorf("unable to unmarshal marshalled object: %w", err)
    42  	}
    43  	return &out, nil
    44  }
    45  
    46  // changeAll calls the given callback for all nodes in
    47  // the given YAML node tree.
    48  func changeAll(root *yaml.Node, cb func(*yaml.Node)) {
    49  	cb(root)
    50  	for _, child := range root.Content {
    51  		changeAll(child, cb)
    52  	}
    53  }
    54  
    55  // SetStyle sets the style for all nodes in the given
    56  // node tree to the given style.
    57  func SetStyle(root *yaml.Node, style yaml.Style) {
    58  	changeAll(root, func(node *yaml.Node) {
    59  		node.Style = style
    60  	})
    61  }