This repository has been archived by the owner on Feb 24, 2020. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 886
/
image_extract.go
146 lines (126 loc) · 4.03 KB
/
image_extract.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
// Copyright 2015 The rkt 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 main
import (
"io/ioutil"
"os"
"path/filepath"
"syscall"
"github.com/coreos/rkt/pkg/fileutil"
"github.com/coreos/rkt/pkg/tar"
"github.com/coreos/rkt/pkg/uid"
"github.com/coreos/rkt/store"
"github.com/spf13/cobra"
)
var (
cmdImageExtract = &cobra.Command{
Use: "extract IMAGE OUTPUT_DIR",
Short: "Extract a stored image to a directory",
Long: `IMAGE should be a string referencing an image: either a hash or an image name.`,
Run: runWrapper(runImageExtract),
}
flagExtractRootfsOnly bool
flagExtractOverwrite bool
)
func init() {
cmdImage.AddCommand(cmdImageExtract)
cmdImageExtract.Flags().BoolVar(&flagExtractRootfsOnly, "rootfs-only", false, "extract rootfs only")
cmdImageExtract.Flags().BoolVar(&flagExtractOverwrite, "overwrite", false, "overwrite output directory")
}
func runImageExtract(cmd *cobra.Command, args []string) (exit int) {
if len(args) != 2 {
cmd.Usage()
return 1
}
outputDir := args[1]
s, err := store.NewStore(getDataDir())
if err != nil {
stderr("image extract: cannot open store: %v", err)
return 1
}
key, err := getStoreKeyFromAppOrHash(s, args[0])
if err != nil {
stderr("image extract: %v", err)
return 1
}
aci, err := s.ReadStream(key)
if err != nil {
stderr("image extract: error reading ACI from the store: %v", err)
return 1
}
// ExtractTar needs an absolute path
absOutputDir, err := filepath.Abs(outputDir)
if err != nil {
stderr("image extract: error converting output to an absolute path: %v", err)
return 1
}
if _, err := os.Stat(absOutputDir); err == nil {
if !flagExtractOverwrite {
stderr("image extract: output directory exists (try --overwrite)")
return 1
}
// don't allow the user to delete the root filesystem by mistake
if absOutputDir == "/" {
stderr("image extract: this would delete your root filesystem. Refusing.")
return 1
}
if err := os.RemoveAll(absOutputDir); err != nil {
stderr("image extract: error removing existing output dir: %v", err)
return 1
}
}
// if the user only asks for the rootfs we extract the image to a temporary
// directory and then move/copy the rootfs to the output directory, if not
// we just extract the image to the output directory
extractDir := absOutputDir
if flagExtractRootfsOnly {
rktTmpDir, err := s.TmpDir()
if err != nil {
stderr("image extract: error creating rkt temporary directory: %v", err)
return 1
}
tmpDir, err := ioutil.TempDir(rktTmpDir, "rkt-image-extract-")
if err != nil {
stderr("image extract: error creating temporary directory: %v", err)
return 1
}
defer os.RemoveAll(tmpDir)
extractDir = tmpDir
} else {
if err := os.MkdirAll(absOutputDir, 0755); err != nil {
stderr("image extract: error creating output directory: %v", err)
return 1
}
}
if err := tar.ExtractTar(aci, extractDir, false, uid.NewBlankUidRange(), nil); err != nil {
stderr("image extract: error extracting ACI: %v", err)
return 1
}
if flagExtractRootfsOnly {
rootfsDir := filepath.Join(extractDir, "rootfs")
if err := os.Rename(rootfsDir, absOutputDir); err != nil {
if e, ok := err.(*os.LinkError); ok && e.Err == syscall.EXDEV {
// it's on a different device, fall back to copying
if err := fileutil.CopyTree(rootfsDir, absOutputDir, uid.NewBlankUidRange()); err != nil {
stderr("image extract: error copying ACI rootfs: %v", err)
return 1
}
} else {
stderr("image extract: error moving ACI rootfs: %v", err)
return 1
}
}
}
return 0
}