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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
package vfs
import (
"fmt"
"os"
"path/filepath"
"strings"
"github.com/containers/storage/drivers"
"github.com/containers/storage/pkg/idtools"
"github.com/containers/storage/pkg/ostree"
"github.com/containers/storage/pkg/system"
"github.com/opencontainers/selinux/go-selinux/label"
)
var (
// CopyDir defines the copy method to use.
CopyDir = dirCopy
)
func init() {
graphdriver.Register("vfs", Init)
}
// Init returns a new VFS driver.
// This sets the home directory for the driver and returns NaiveDiffDriver.
func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
d := &Driver{
homes: []string{home},
idMappings: idtools.NewIDMappingsFromMaps(uidMaps, gidMaps),
}
rootIDs := d.idMappings.RootPair()
if err := idtools.MkdirAllAndChown(home, 0700, rootIDs); err != nil {
return nil, err
}
for _, option := range options {
if strings.HasPrefix(option, "vfs.imagestore=") {
d.homes = append(d.homes, strings.Split(option[15:], ",")...)
continue
}
if strings.HasPrefix(option, ".imagestore=") {
d.homes = append(d.homes, strings.Split(option[12:], ",")...)
continue
}
if strings.HasPrefix(option, "vfs.ostree_repo=") {
if !ostree.OstreeSupport() {
return nil, fmt.Errorf("vfs: ostree_repo specified but support for ostree is missing")
}
d.ostreeRepo = option[16:]
}
if strings.HasPrefix(option, ".ostree_repo=") {
if !ostree.OstreeSupport() {
return nil, fmt.Errorf("vfs: ostree_repo specified but support for ostree is missing")
}
d.ostreeRepo = option[13:]
}
if strings.HasPrefix(option, "vfs.mountopt=") {
return nil, fmt.Errorf("vfs driver does not support mount options")
}
}
if d.ostreeRepo != "" {
rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
if err != nil {
return nil, err
}
if err := ostree.CreateOSTreeRepository(d.ostreeRepo, rootUID, rootGID); err != nil {
return nil, err
}
}
return graphdriver.NewNaiveDiffDriver(d, graphdriver.NewNaiveLayerIDMapUpdater(d)), nil
}
// Driver holds information about the driver, home directory of the driver.
// Driver implements graphdriver.ProtoDriver. It uses only basic vfs operations.
// In order to support layering, files are copied from the parent layer into the new layer. There is no copy-on-write support.
// Driver must be wrapped in NaiveDiffDriver to be used as a graphdriver.Driver
type Driver struct {
homes []string
idMappings *idtools.IDMappings
ostreeRepo string
}
func (d *Driver) String() string {
return "vfs"
}
// Status is used for implementing the graphdriver.ProtoDriver interface. VFS does not currently have any status information.
func (d *Driver) Status() [][2]string {
return nil
}
// Metadata is used for implementing the graphdriver.ProtoDriver interface. VFS does not currently have any meta data.
func (d *Driver) Metadata(id string) (map[string]string, error) {
return nil, nil
}
// Cleanup is used to implement graphdriver.ProtoDriver. There is no cleanup required for this driver.
func (d *Driver) Cleanup() error {
return nil
}
// CreateFromTemplate creates a layer with the same contents and parent as another layer.
func (d *Driver) CreateFromTemplate(id, template string, templateIDMappings *idtools.IDMappings, parent string, parentIDMappings *idtools.IDMappings, opts *graphdriver.CreateOpts, readWrite bool) error {
if readWrite {
return d.CreateReadWrite(id, template, opts)
}
return d.Create(id, template, opts)
}
// CreateReadWrite creates a layer that is writable for use as a container
// file system.
func (d *Driver) CreateReadWrite(id, parent string, opts *graphdriver.CreateOpts) error {
return d.create(id, parent, opts, false)
}
// Create prepares the filesystem for the VFS driver and copies the directory for the given id under the parent.
func (d *Driver) Create(id, parent string, opts *graphdriver.CreateOpts) error {
return d.create(id, parent, opts, true)
}
func (d *Driver) create(id, parent string, opts *graphdriver.CreateOpts, ro bool) error {
if opts != nil && len(opts.StorageOpt) != 0 {
return fmt.Errorf("--storage-opt is not supported for vfs")
}
dir := d.dir(id)
rootIDs := d.idMappings.RootPair()
if err := idtools.MkdirAllAndChown(filepath.Dir(dir), 0700, rootIDs); err != nil {
return err
}
if parent != "" {
st, err := system.Stat(d.dir(parent))
if err != nil {
return err
}
rootIDs.UID = int(st.UID())
rootIDs.GID = int(st.GID())
}
if err := idtools.MkdirAndChown(dir, 0755, rootIDs); err != nil {
return err
}
labelOpts := []string{"level:s0"}
if _, mountLabel, err := label.InitLabels(labelOpts); err == nil {
label.SetFileLabel(dir, mountLabel)
}
if parent != "" {
parentDir, err := d.Get(parent, graphdriver.MountOpts{})
if err != nil {
return fmt.Errorf("%s: %s", parent, err)
}
if err := dirCopy(parentDir, dir); err != nil {
return err
}
}
if ro && d.ostreeRepo != "" {
if err := ostree.ConvertToOSTree(d.ostreeRepo, dir, id); err != nil {
return err
}
}
return nil
}
func (d *Driver) dir(id string) string {
for i, home := range d.homes {
if i > 0 {
home = filepath.Join(home, d.String())
}
candidate := filepath.Join(home, "dir", filepath.Base(id))
fi, err := os.Stat(candidate)
if err == nil && fi.IsDir() {
return candidate
}
}
return filepath.Join(d.homes[0], "dir", filepath.Base(id))
}
// Remove deletes the content from the directory for a given id.
func (d *Driver) Remove(id string) error {
if d.ostreeRepo != "" {
// Ignore errors, we don't want to fail if the ostree branch doesn't exist,
ostree.DeleteOSTree(d.ostreeRepo, id)
}
return system.EnsureRemoveAll(d.dir(id))
}
// Get returns the directory for the given id.
func (d *Driver) Get(id string, options graphdriver.MountOpts) (_ string, retErr error) {
dir := d.dir(id)
if len(options.Options) > 0 {
return "", fmt.Errorf("vfs driver does not support mount options")
}
if st, err := os.Stat(dir); err != nil {
return "", err
} else if !st.IsDir() {
return "", fmt.Errorf("%s: not a directory", dir)
}
return dir, nil
}
// Put is a noop for vfs that return nil for the error, since this driver has no runtime resources to clean up.
func (d *Driver) Put(id string) error {
// The vfs driver has no runtime resources (e.g. mounts)
// to clean up, so we don't need anything here
return nil
}
// Exists checks to see if the directory exists for the given id.
func (d *Driver) Exists(id string) bool {
_, err := os.Stat(d.dir(id))
return err == nil
}
// AdditionalImageStores returns additional image stores supported by the driver
func (d *Driver) AdditionalImageStores() []string {
if len(d.homes) > 1 {
return d.homes[1:]
}
return nil
}
|