-
Notifications
You must be signed in to change notification settings - Fork 2.2k
/
hasher.go
155 lines (142 loc) · 3.7 KB
/
hasher.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
// Copyright 2019 The Kubernetes Authors.
// SPDX-License-Identifier: Apache-2.0
package hasher
import (
"crypto/sha256"
"encoding/json"
"fmt"
"sort"
"sigs.k8s.io/kustomize/kyaml/yaml"
)
// SortArrayAndComputeHash sorts a string array and
// returns a hash for it
func SortArrayAndComputeHash(s []string) (string, error) {
sort.Strings(s)
data, err := json.Marshal(s)
if err != nil {
return "", err
}
return encode(hex256(string(data)))
}
// Copied from https://github.com/kubernetes/kubernetes
// /blob/master/pkg/kubectl/util/hash/hash.go
func encode(hex string) (string, error) {
if len(hex) < 10 {
return "", fmt.Errorf(
"input length must be at least 10")
}
enc := []rune(hex[:10])
for i := range enc {
switch enc[i] {
case '0':
enc[i] = 'g'
case '1':
enc[i] = 'h'
case '3':
enc[i] = 'k'
case 'a':
enc[i] = 'm'
case 'e':
enc[i] = 't'
}
}
return string(enc), nil
}
// hex256 returns the hex form of the sha256 of the argument.
func hex256(data string) string {
return fmt.Sprintf("%x", sha256.Sum256([]byte(data)))
}
// Hasher computes the hash of an RNode.
type Hasher struct{}
// Hash returns a hash of the argument.
func (h *Hasher) Hash(node *yaml.RNode) (r string, err error) {
var encoded string
switch node.GetKind() {
case "ConfigMap":
encoded, err = encodeConfigMap(node)
case "Secret":
encoded, err = encodeSecret(node)
default:
var encodedBytes []byte
encodedBytes, err = json.Marshal(node.YNode())
encoded = string(encodedBytes)
}
if err != nil {
return "", err
}
return encode(hex256(encoded))
}
func getNodeValues(
node *yaml.RNode, paths []string) (map[string]interface{}, error) {
values := make(map[string]interface{})
for _, p := range paths {
vn, err := node.Pipe(yaml.Lookup(p))
if err != nil {
return map[string]interface{}{}, err
}
if vn == nil {
values[p] = ""
continue
}
if vn.YNode().Kind != yaml.ScalarNode {
vs, err := vn.MarshalJSON()
if err != nil {
return map[string]interface{}{}, err
}
// data, binaryData and stringData are all maps
var v map[string]interface{}
json.Unmarshal(vs, &v)
values[p] = v
} else {
values[p] = vn.YNode().Value
}
}
return values, nil
}
// encodeConfigMap encodes a ConfigMap.
// Data, Kind, and Name are taken into account.
// BinaryData is included if it's not empty to avoid useless key in output.
func encodeConfigMap(node *yaml.RNode) (string, error) {
// get fields
paths := []string{"metadata/name", "data", "binaryData"}
values, err := getNodeValues(node, paths)
if err != nil {
return "", err
}
m := map[string]interface{}{
"kind": "ConfigMap",
"name": values["metadata/name"],
"data": values["data"],
}
if _, ok := values["binaryData"].(map[string]interface{}); ok {
m["binaryData"] = values["binaryData"]
}
// json.Marshal sorts the keys in a stable order in the encoding
data, err := json.Marshal(m)
if err != nil {
return "", err
}
return string(data), nil
}
// encodeSecret encodes a Secret.
// Data, Kind, Name, and Type are taken into account.
// StringData is included if it's not empty to avoid useless key in output.
func encodeSecret(node *yaml.RNode) (string, error) {
// get fields
paths := []string{"type", "metadata/name", "data", "stringData"}
values, err := getNodeValues(node, paths)
if err != nil {
return "", err
}
m := map[string]interface{}{"kind": "Secret", "type": values["type"],
"name": values["metadata/name"], "data": values["data"]}
if _, ok := values["stringData"].(map[string]interface{}); ok {
m["stringData"] = values["stringData"]
}
// json.Marshal sorts the keys in a stable order in the encoding
data, err := json.Marshal(m)
if err != nil {
return "", err
}
return string(data), nil
}