-
Notifications
You must be signed in to change notification settings - Fork 252
/
importlayer.go
135 lines (124 loc) · 3.91 KB
/
importlayer.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
package wclayer
import (
"io/ioutil"
"os"
"path/filepath"
"github.com/Microsoft/go-winio"
"github.com/Microsoft/hcsshim/internal/hcserror"
"github.com/Microsoft/hcsshim/internal/safefile"
"github.com/sirupsen/logrus"
)
// ImportLayer will take the contents of the folder at importFolderPath and import
// that into a layer with the id layerId. Note that in order to correctly populate
// the layer and interperet the transport format, all parent layers must already
// be present on the system at the paths provided in parentLayerPaths.
func ImportLayer(path string, importFolderPath string, parentLayerPaths []string) (err error) {
title := "hcsshim::ImportLayer"
fields := logrus.Fields{
"path": path,
"importFolderPath": importFolderPath,
}
logrus.WithFields(fields).Debug(title)
defer func() {
if err != nil {
fields[logrus.ErrorKey] = err
logrus.WithFields(fields).Error(err)
} else {
logrus.WithFields(fields).Debug(title + " - succeeded")
}
}()
// Generate layer descriptors
layers, err := layerPathsToDescriptors(parentLayerPaths)
if err != nil {
return err
}
err = importLayer(&stdDriverInfo, path, importFolderPath, layers)
if err != nil {
return hcserror.New(err, title+" - failed", "")
}
return nil
}
// LayerWriter is an interface that supports writing a new container image layer.
type LayerWriter interface {
// Add adds a file to the layer with given metadata.
Add(name string, fileInfo *winio.FileBasicInfo) error
// AddLink adds a hard link to the layer. The target must already have been added.
AddLink(name string, target string) error
// Remove removes a file that was present in a parent layer from the layer.
Remove(name string) error
// Write writes data to the current file. The data must be in the format of a Win32
// backup stream.
Write(b []byte) (int, error)
// Close finishes the layer writing process and releases any resources.
Close() error
}
type legacyLayerWriterWrapper struct {
*legacyLayerWriter
path string
parentLayerPaths []string
}
func (r *legacyLayerWriterWrapper) Close() error {
defer os.RemoveAll(r.root.Name())
defer r.legacyLayerWriter.CloseRoots()
err := r.legacyLayerWriter.Close()
if err != nil {
return err
}
if err = ImportLayer(r.destRoot.Name(), r.path, r.parentLayerPaths); err != nil {
return err
}
for _, name := range r.Tombstones {
if err = safefile.RemoveRelative(name, r.destRoot); err != nil && !os.IsNotExist(err) {
return err
}
}
// Add any hard links that were collected.
for _, lnk := range r.PendingLinks {
if err = safefile.RemoveRelative(lnk.Path, r.destRoot); err != nil && !os.IsNotExist(err) {
return err
}
if err = safefile.LinkRelative(lnk.Target, lnk.TargetRoot, lnk.Path, r.destRoot); err != nil {
return err
}
}
// Prepare the utility VM for use if one is present in the layer.
if r.HasUtilityVM {
err := safefile.EnsureNotReparsePointRelative("UtilityVM", r.destRoot)
if err != nil {
return err
}
err = ProcessUtilityVMImage(filepath.Join(r.destRoot.Name(), "UtilityVM"))
if err != nil {
return err
}
}
return nil
}
// NewLayerWriter returns a new layer writer for creating a layer on disk.
// The caller must have taken the SeBackupPrivilege and SeRestorePrivilege privileges
// to call this and any methods on the resulting LayerWriter.
func NewLayerWriter(path string, parentLayerPaths []string) (LayerWriter, error) {
if len(parentLayerPaths) == 0 {
// This is a base layer. It gets imported differently.
f, err := safefile.OpenRoot(path)
if err != nil {
return nil, err
}
return &baseLayerWriter{
root: f,
}, nil
}
importPath, err := ioutil.TempDir("", "hcs")
if err != nil {
return nil, err
}
w, err := newLegacyLayerWriter(importPath, parentLayerPaths, path)
if err != nil {
return nil, err
}
return &legacyLayerWriterWrapper{
legacyLayerWriter: w,
path: importPath,
parentLayerPaths: parentLayerPaths,
}, nil
}