forked from kubernetes-sigs/kustomize
/
image.go
171 lines (153 loc) · 4.12 KB
/
image.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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
/*
Copyright 2019 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 transformers
import (
"fmt"
"regexp"
"strings"
"sigs.k8s.io/kustomize/pkg/image"
"sigs.k8s.io/kustomize/pkg/resmap"
)
// imageTransformer replace image names and tags
type imageTransformer struct {
images []image.Image
}
var _ Transformer = &imageTransformer{}
// NewImageTransformer constructs an imageTransformer.
func NewImageTransformer(slice []image.Image) (Transformer, error) {
return &imageTransformer{slice}, nil
}
// Transform finds the matching images and replaces name, tag and/or digest
func (pt *imageTransformer) Transform(resources resmap.ResMap) error {
if len(pt.images) == 0 {
return nil
}
for _, res := range resources {
err := pt.findAndReplaceImage(res.Map())
if err != nil {
return err
}
}
return nil
}
/*
findAndReplaceImage replaces the image name and tags inside one object
It searches the object for container session
then loops though all images inside containers session,
finds matched ones and update the image name and tag name
*/
func (pt *imageTransformer) findAndReplaceImage(obj map[string]interface{}) error {
paths := []string{"containers", "initContainers"}
found := false
for _, path := range paths {
_, found = obj[path]
if found {
err := pt.updateContainers(obj, path)
if err != nil {
return err
}
}
}
if !found {
return pt.findContainers(obj)
}
return nil
}
func (pt *imageTransformer) updateContainers(obj map[string]interface{}, path string) error {
containers, ok := obj[path].([]interface{})
if !ok {
return fmt.Errorf("containers path is not of type []interface{} but %T", obj[path])
}
for i := range containers {
container := containers[i].(map[string]interface{})
containerImage, found := container["image"]
if !found {
continue
}
imageName := containerImage.(string)
for _, img := range pt.images {
if !isImageMatched(imageName, img.Name) {
continue
}
name, tag := split(imageName)
if img.NewName != "" {
name = img.NewName
}
if img.NewTag != "" {
tag = ":" + img.NewTag
}
if img.Digest != "" {
tag = "@" + img.Digest
}
container["image"] = name + tag
break
}
}
return nil
}
func (pt *imageTransformer) findContainers(obj map[string]interface{}) error {
for key := range obj {
switch typedV := obj[key].(type) {
case map[string]interface{}:
err := pt.findAndReplaceImage(typedV)
if err != nil {
return err
}
case []interface{}:
for i := range typedV {
item := typedV[i]
typedItem, ok := item.(map[string]interface{})
if ok {
err := pt.findAndReplaceImage(typedItem)
if err != nil {
return err
}
}
}
}
}
return nil
}
func isImageMatched(s, t string) bool {
// Tag values are limited to [a-zA-Z0-9_.-].
pattern, _ := regexp.Compile("^" + t + "(:[a-zA-Z0-9_.-]*)?$")
return pattern.MatchString(s)
}
// split separates and returns the name and tag parts
// from the image string using either colon `:` or at `@` separators.
// Note that the returned tag keeps its separator.
func split(imageName string) (name string, tag string) {
// check if image name contains a domain
// if domain is present, ignore domain and check for `:`
ic := -1
if slashIndex := strings.Index(imageName, "/"); slashIndex < 0 {
ic = strings.LastIndex(imageName, ":")
} else {
lastIc := strings.LastIndex(imageName[slashIndex:], ":")
// set ic only if `:` is present
if lastIc > 0 {
ic = slashIndex + lastIc
}
}
ia := strings.LastIndex(imageName, "@")
if ic < 0 && ia < 0 {
return imageName, ""
}
i := ic
if ic < 0 {
i = ia
}
name = imageName[:i]
tag = imageName[i:]
return
}