Matthias Andreas Benkard | 832a54e | 2019-01-29 09:27:38 +0100 | [diff] [blame^] | 1 | /* |
| 2 | Copyright 2017 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 mergepatch |
| 18 | |
| 19 | import ( |
| 20 | "fmt" |
| 21 | "reflect" |
| 22 | |
| 23 | "github.com/davecgh/go-spew/spew" |
| 24 | "github.com/ghodss/yaml" |
| 25 | ) |
| 26 | |
| 27 | // PreconditionFunc asserts that an incompatible change is not present within a patch. |
| 28 | type PreconditionFunc func(interface{}) bool |
| 29 | |
| 30 | // RequireKeyUnchanged returns a precondition function that fails if the provided key |
| 31 | // is present in the patch (indicating that its value has changed). |
| 32 | func RequireKeyUnchanged(key string) PreconditionFunc { |
| 33 | return func(patch interface{}) bool { |
| 34 | patchMap, ok := patch.(map[string]interface{}) |
| 35 | if !ok { |
| 36 | return true |
| 37 | } |
| 38 | |
| 39 | // The presence of key means that its value has been changed, so the test fails. |
| 40 | _, ok = patchMap[key] |
| 41 | return !ok |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | // RequireMetadataKeyUnchanged creates a precondition function that fails |
| 46 | // if the metadata.key is present in the patch (indicating its value |
| 47 | // has changed). |
| 48 | func RequireMetadataKeyUnchanged(key string) PreconditionFunc { |
| 49 | return func(patch interface{}) bool { |
| 50 | patchMap, ok := patch.(map[string]interface{}) |
| 51 | if !ok { |
| 52 | return true |
| 53 | } |
| 54 | patchMap1, ok := patchMap["metadata"] |
| 55 | if !ok { |
| 56 | return true |
| 57 | } |
| 58 | patchMap2, ok := patchMap1.(map[string]interface{}) |
| 59 | if !ok { |
| 60 | return true |
| 61 | } |
| 62 | _, ok = patchMap2[key] |
| 63 | return !ok |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | func ToYAMLOrError(v interface{}) string { |
| 68 | y, err := toYAML(v) |
| 69 | if err != nil { |
| 70 | return err.Error() |
| 71 | } |
| 72 | |
| 73 | return y |
| 74 | } |
| 75 | |
| 76 | func toYAML(v interface{}) (string, error) { |
| 77 | y, err := yaml.Marshal(v) |
| 78 | if err != nil { |
| 79 | return "", fmt.Errorf("yaml marshal failed:%v\n%v\n", err, spew.Sdump(v)) |
| 80 | } |
| 81 | |
| 82 | return string(y), nil |
| 83 | } |
| 84 | |
| 85 | // HasConflicts returns true if the left and right JSON interface objects overlap with |
| 86 | // different values in any key. All keys are required to be strings. Since patches of the |
| 87 | // same Type have congruent keys, this is valid for multiple patch types. This method |
| 88 | // supports JSON merge patch semantics. |
| 89 | // |
| 90 | // NOTE: Numbers with different types (e.g. int(0) vs int64(0)) will be detected as conflicts. |
| 91 | // Make sure the unmarshaling of left and right are consistent (e.g. use the same library). |
| 92 | func HasConflicts(left, right interface{}) (bool, error) { |
| 93 | switch typedLeft := left.(type) { |
| 94 | case map[string]interface{}: |
| 95 | switch typedRight := right.(type) { |
| 96 | case map[string]interface{}: |
| 97 | for key, leftValue := range typedLeft { |
| 98 | rightValue, ok := typedRight[key] |
| 99 | if !ok { |
| 100 | continue |
| 101 | } |
| 102 | if conflict, err := HasConflicts(leftValue, rightValue); err != nil || conflict { |
| 103 | return conflict, err |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | return false, nil |
| 108 | default: |
| 109 | return true, nil |
| 110 | } |
| 111 | case []interface{}: |
| 112 | switch typedRight := right.(type) { |
| 113 | case []interface{}: |
| 114 | if len(typedLeft) != len(typedRight) { |
| 115 | return true, nil |
| 116 | } |
| 117 | |
| 118 | for i := range typedLeft { |
| 119 | if conflict, err := HasConflicts(typedLeft[i], typedRight[i]); err != nil || conflict { |
| 120 | return conflict, err |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | return false, nil |
| 125 | default: |
| 126 | return true, nil |
| 127 | } |
| 128 | case string, float64, bool, int, int64, nil: |
| 129 | return !reflect.DeepEqual(left, right), nil |
| 130 | default: |
| 131 | return true, fmt.Errorf("unknown type: %v", reflect.TypeOf(left)) |
| 132 | } |
| 133 | } |