forked from moby/moby
-
Notifications
You must be signed in to change notification settings - Fork 0
/
cp.go
324 lines (271 loc) · 10 KB
/
cp.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
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
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
package client
import (
"encoding/base64"
"encoding/json"
"fmt"
"io"
"net/http"
"net/url"
"os"
"path/filepath"
"strings"
"github.com/docker/docker/api/types"
Cli "github.com/docker/docker/cli"
"github.com/docker/docker/pkg/archive"
flag "github.com/docker/docker/pkg/mflag"
)
type copyDirection int
const (
fromContainer copyDirection = (1 << iota)
toContainer
acrossContainers = fromContainer | toContainer
)
// CmdCp copies files/folders to or from a path in a container.
//
// When copying from a container, if LOCALPATH is '-' the data is written as a
// tar archive file to STDOUT.
//
// When copying to a container, if LOCALPATH is '-' the data is read as a tar
// archive file from STDIN, and the destination CONTAINER:PATH, must specify
// a directory.
//
// Usage:
// docker cp CONTAINER:PATH LOCALPATH|-
// docker cp LOCALPATH|- CONTAINER:PATH
func (cli *DockerCli) CmdCp(args ...string) error {
cmd := Cli.Subcmd(
"cp",
[]string{"CONTAINER:PATH LOCALPATH|-", "LOCALPATH|- CONTAINER:PATH"},
strings.Join([]string{
"Copy files/folders between a container and your host.\n",
"Use '-' as the source to read a tar archive from stdin\n",
"and extract it to a directory destination in a container.\n",
"Use '-' as the destination to stream a tar archive of a\n",
"container source to stdout.",
}, ""),
true,
)
cmd.Require(flag.Exact, 2)
cmd.ParseFlags(args, true)
if cmd.Arg(0) == "" {
return fmt.Errorf("source can not be empty")
}
if cmd.Arg(1) == "" {
return fmt.Errorf("destination can not be empty")
}
srcContainer, srcPath := splitCpArg(cmd.Arg(0))
dstContainer, dstPath := splitCpArg(cmd.Arg(1))
var direction copyDirection
if srcContainer != "" {
direction |= fromContainer
}
if dstContainer != "" {
direction |= toContainer
}
switch direction {
case fromContainer:
return cli.copyFromContainer(srcContainer, srcPath, dstPath)
case toContainer:
return cli.copyToContainer(srcPath, dstContainer, dstPath)
case acrossContainers:
// Copying between containers isn't supported.
return fmt.Errorf("copying between containers is not supported")
default:
// User didn't specify any container.
return fmt.Errorf("must specify at least one container source")
}
}
// We use `:` as a delimiter between CONTAINER and PATH, but `:` could also be
// in a valid LOCALPATH, like `file:name.txt`. We can resolve this ambiguity by
// requiring a LOCALPATH with a `:` to be made explicit with a relative or
// absolute path:
// `/path/to/file:name.txt` or `./file:name.txt`
//
// This is apparently how `scp` handles this as well:
// http://www.cyberciti.biz/faq/rsync-scp-file-name-with-colon-punctuation-in-it/
//
// We can't simply check for a filepath separator because container names may
// have a separator, e.g., "host0/cname1" if container is in a Docker cluster,
// so we have to check for a `/` or `.` prefix. Also, in the case of a Windows
// client, a `:` could be part of an absolute Windows path, in which case it
// is immediately proceeded by a backslash.
func splitCpArg(arg string) (container, path string) {
if filepath.IsAbs(arg) {
// Explicit local absolute path, e.g., `C:\foo` or `/foo`.
return "", arg
}
parts := strings.SplitN(arg, ":", 2)
if len(parts) == 1 || strings.HasPrefix(parts[0], ".") {
// Either there's no `:` in the arg
// OR it's an explicit local relative path like `./file:name.txt`.
return "", arg
}
return parts[0], parts[1]
}
func (cli *DockerCli) statContainerPath(containerName, path string) (types.ContainerPathStat, error) {
var stat types.ContainerPathStat
query := make(url.Values, 1)
query.Set("path", filepath.ToSlash(path)) // Normalize the paths used in the API.
urlStr := fmt.Sprintf("/containers/%s/archive?%s", containerName, query.Encode())
response, err := cli.call("HEAD", urlStr, nil, nil)
if err != nil {
return stat, err
}
defer response.body.Close()
if response.statusCode != http.StatusOK {
return stat, fmt.Errorf("unexpected status code from daemon: %d", response.statusCode)
}
return getContainerPathStatFromHeader(response.header)
}
func getContainerPathStatFromHeader(header http.Header) (types.ContainerPathStat, error) {
var stat types.ContainerPathStat
encodedStat := header.Get("X-Docker-Container-Path-Stat")
statDecoder := base64.NewDecoder(base64.StdEncoding, strings.NewReader(encodedStat))
err := json.NewDecoder(statDecoder).Decode(&stat)
if err != nil {
err = fmt.Errorf("unable to decode container path stat header: %s", err)
}
return stat, err
}
func resolveLocalPath(localPath string) (absPath string, err error) {
if absPath, err = filepath.Abs(localPath); err != nil {
return
}
return archive.PreserveTrailingDotOrSeparator(absPath, localPath), nil
}
func (cli *DockerCli) copyFromContainer(srcContainer, srcPath, dstPath string) (err error) {
if dstPath != "-" {
// Get an absolute destination path.
dstPath, err = resolveLocalPath(dstPath)
if err != nil {
return err
}
}
query := make(url.Values, 1)
query.Set("path", filepath.ToSlash(srcPath)) // Normalize the paths used in the API.
urlStr := fmt.Sprintf("/containers/%s/archive?%s", srcContainer, query.Encode())
response, err := cli.call("GET", urlStr, nil, nil)
if err != nil {
return err
}
defer response.body.Close()
if response.statusCode != http.StatusOK {
return fmt.Errorf("unexpected status code from daemon: %d", response.statusCode)
}
if dstPath == "-" {
// Send the response to STDOUT.
_, err = io.Copy(os.Stdout, response.body)
return err
}
// In order to get the copy behavior right, we need to know information
// about both the source and the destination. The response headers include
// stat info about the source that we can use in deciding exactly how to
// copy it locally. Along with the stat info about the local destination,
// we have everything we need to handle the multiple possibilities there
// can be when copying a file/dir from one location to another file/dir.
stat, err := getContainerPathStatFromHeader(response.header)
if err != nil {
return fmt.Errorf("unable to get resource stat from response: %s", err)
}
// Prepare source copy info.
srcInfo := archive.CopyInfo{
Path: srcPath,
Exists: true,
IsDir: stat.Mode.IsDir(),
}
// See comments in the implementation of `archive.CopyTo` for exactly what
// goes into deciding how and whether the source archive needs to be
// altered for the correct copy behavior.
return archive.CopyTo(response.body, srcInfo, dstPath)
}
func (cli *DockerCli) copyToContainer(srcPath, dstContainer, dstPath string) (err error) {
if srcPath != "-" {
// Get an absolute source path.
srcPath, err = resolveLocalPath(srcPath)
if err != nil {
return err
}
}
// In order to get the copy behavior right, we need to know information
// about both the source and destination. The API is a simple tar
// archive/extract API but we can use the stat info header about the
// destination to be more informed about exactly what the destination is.
// Prepare destination copy info by stat-ing the container path.
dstInfo := archive.CopyInfo{Path: dstPath}
dstStat, err := cli.statContainerPath(dstContainer, dstPath)
// If the destination is a symbolic link, we should evaluate it.
if err == nil && dstStat.Mode&os.ModeSymlink != 0 {
linkTarget := dstStat.LinkTarget
if !filepath.IsAbs(linkTarget) {
// Join with the parent directory.
dstParent, _ := archive.SplitPathDirEntry(dstPath)
linkTarget = filepath.Join(dstParent, linkTarget)
}
dstInfo.Path = linkTarget
dstStat, err = cli.statContainerPath(dstContainer, linkTarget)
}
// Ignore any error and assume that the parent directory of the destination
// path exists, in which case the copy may still succeed. If there is any
// type of conflict (e.g., non-directory overwriting an existing directory
// or vice versia) the extraction will fail. If the destination simply did
// not exist, but the parent directory does, the extraction will still
// succeed.
if err == nil {
dstInfo.Exists, dstInfo.IsDir = true, dstStat.Mode.IsDir()
}
var (
content io.Reader
resolvedDstPath string
)
if srcPath == "-" {
// Use STDIN.
content = os.Stdin
resolvedDstPath = dstInfo.Path
if !dstInfo.IsDir {
return fmt.Errorf("destination %q must be a directory", fmt.Sprintf("%s:%s", dstContainer, dstPath))
}
} else {
// Prepare source copy info.
srcInfo, err := archive.CopyInfoSourcePath(srcPath)
if err != nil {
return err
}
srcArchive, err := archive.TarResource(srcInfo)
if err != nil {
return err
}
defer srcArchive.Close()
// With the stat info about the local source as well as the
// destination, we have enough information to know whether we need to
// alter the archive that we upload so that when the server extracts
// it to the specified directory in the container we get the disired
// copy behavior.
// See comments in the implementation of `archive.PrepareArchiveCopy`
// for exactly what goes into deciding how and whether the source
// archive needs to be altered for the correct copy behavior when it is
// extracted. This function also infers from the source and destination
// info which directory to extract to, which may be the parent of the
// destination that the user specified.
dstDir, preparedArchive, err := archive.PrepareArchiveCopy(srcArchive, srcInfo, dstInfo)
if err != nil {
return err
}
defer preparedArchive.Close()
resolvedDstPath = dstDir
content = preparedArchive
}
query := make(url.Values, 2)
query.Set("path", filepath.ToSlash(resolvedDstPath)) // Normalize the paths used in the API.
// Do not allow for an existing directory to be overwritten by a non-directory and vice versa.
query.Set("noOverwriteDirNonDir", "true")
urlStr := fmt.Sprintf("/containers/%s/archive?%s", dstContainer, query.Encode())
response, err := cli.stream("PUT", urlStr, &streamOpts{in: content})
if err != nil {
return err
}
defer response.body.Close()
if response.statusCode != http.StatusOK {
return fmt.Errorf("unexpected status code from daemon: %d", response.statusCode)
}
return nil
}