lift code from docker/volume/mounts for splitting windows volumes

Using the API as provided from the `mounts` package imposes validation
on the `src:dest` which shouldn't be performed at this time. To workaround
that lift the internal code from that library required to only perform
the split.

drivers/docker/utils.go

@@ -2,18 +2,78 @@ package docker
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"os"
 	"os/exec"
 	"path/filepath"
+	"regexp"
 	"strings"
 
 	"github.com/docker/cli/cli/config/configfile"
 	"github.com/docker/distribution/reference"
 	"github.com/docker/docker/registry"
-	"github.com/docker/docker/volume/mounts"
 	docker "github.com/fsouza/go-dockerclient"
+	"github.com/pkg/errors"
+)
+
+const (
+	// Spec should be in the format [source:]destination[:mode]
+	//
+	// Examples: c:\foo bar:d:rw
+	//           c:\foo:d:\bar
+	//           myname:d:
+	//           d:\
+	//
+	// Explanation of this regex! Thanks @thaJeztah on IRC and gist for help. See
+	// https://gist.github.com/thaJeztah/6185659e4978789fb2b2. A good place to
+	// test is https://regex-golang.appspot.com/assets/html/index.html
+	//
+	// Useful link for referencing named capturing groups:
+	// http://stackoverflow.com/questions/20750843/using-named-matches-from-go-regex
+	//
+	// There are three match groups: source, destination and mode.
+	//
+
+	// rxHostDir is the first option of a source
+	rxHostDir = `(?:\\\\\?\\)?[a-z]:[\\/](?:[^\\/:*?"<>|\r\n]+[\\/]?)*`
+	// rxName is the second option of a source
+	rxName = `[^\\/:*?"<>|\r\n]+`
+
+	// RXReservedNames are reserved names not possible on Windows
+	rxReservedNames = `(con)|(prn)|(nul)|(aux)|(com[1-9])|(lpt[1-9])`
+
+	// rxPipe is a named path pipe (starts with `\\.\pipe\`, possibly with / instead of \)
+	rxPipe = `[/\\]{2}.[/\\]pipe[/\\][^:*?"<>|\r\n]+`
+	// rxSource is the combined possibilities for a source
+	rxSource = `((?P<source>((` + rxHostDir + `)|(` + rxName + `)|(` + rxPipe + `))):)?`
+
+	// Source. Can be either a host directory, a name, or omitted:
+	//  HostDir:
+	//    -  Essentially using the folder solution from
+	//       https://www.safaribooksonline.com/library/view/regular-expressions-cookbook/9781449327453/ch08s18.html
+	//       but adding case insensitivity.
+	//    -  Must be an absolute path such as c:\path
+	//    -  Can include spaces such as `c:\program files`
+	//    -  And then followed by a colon which is not in the capture group
+	//    -  And can be optional
+	//  Name:
+	//    -  Must not contain invalid NTFS filename characters (https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx)
+	//    -  And then followed by a colon which is not in the capture group
+	//    -  And can be optional
+
+	// rxDestination is the regex expression for the mount destination
+	rxDestination = `(?P<destination>((?:\\\\\?\\)?([a-z]):((?:[\\/][^\\/:*?"<>\r\n]+)*[\\/]?))|(` + rxPipe + `))`
+
+	// Destination (aka container path):
+	//    -  Variation on hostdir but can be a drive followed by colon as well
+	//    -  If a path, must be absolute. Can include spaces
+	//    -  Drive cannot be c: (explicitly checked in code, not RegEx)
+
+	// rxMode is the regex expression for the mode of the mount
+	// Mode (optional):
+	//    -  Hopefully self explanatory in comparison to above regex's.
+	//    -  Colon is not in the capture group
+	rxMode = `(:(?P<mode>(?i)ro|rw))?`
 )
 
 func parseDockerImage(image string) (repo, tag string) {
@@ -222,6 +282,10 @@ func isParentPath(parent, path string) bool {
 	return err == nil && !strings.HasPrefix(rel, "..")
 }
 
+func errInvalidSpec(spec string) error {
+	return errors.Errorf("invalid volume specification: '%s'", spec)
+}
+
 func parseVolumeSpec(volBind, os string) (hostPath string, containerPath string, mode string, err error) {
 	if os == "windows" {
 		return parseVolumeSpecWindows(volBind)
@@ -229,27 +293,98 @@ func parseVolumeSpec(volBind, os string) (hostPath string, containerPath string,
 	return parseVolumeSpecLinux(volBind)
 }
 
-func parseVolumeSpecWindows(volBind string) (hostPath string, containerPath string, mode string, err error) {
+type fileInfoProvider interface {
-	parser := mounts.NewParser("windows")
+	fileInfo(path string) (exist, isDir bool, err error)
-	m, err := parser.ParseMountRaw(volBind, "")
+}
+
+type defaultFileInfoProvider struct {
+}
+
+func (defaultFileInfoProvider) fileInfo(path string) (exist, isDir bool, err error) {
+	fi, err := os.Stat(path)
 	if err != nil {
-		return "", "", "", err
+		if !os.IsNotExist(err) {
+			return false, false, err
+		}
+		return false, false, nil
+	}
+	return true, fi.IsDir(), nil
+}
+
+var currentFileInfoProvider fileInfoProvider = defaultFileInfoProvider{}
+
+func windowsSplitRawSpec(raw, destRegex string) ([]string, error) {
+	specExp := regexp.MustCompile(`^` + rxSource + destRegex + rxMode + `$`)
+	match := specExp.FindStringSubmatch(strings.ToLower(raw))
+
+	// Must have something back
+	if len(match) == 0 {
+		return nil, errInvalidSpec(raw)
 	}
 
-	src := m.Source
+	var split []string
-	if src == "" && strings.Contains(volBind, m.Name) {
+	matchgroups := make(map[string]string)
-		src = m.Name
+	// Pull out the sub expressions from the named capture groups
+	for i, name := range specExp.SubexpNames() {
+		matchgroups[name] = strings.ToLower(match[i])
+	}
+	if source, exists := matchgroups["source"]; exists {
+		if source != "" {
+			split = append(split, source)
+		}
+	}
+	if destination, exists := matchgroups["destination"]; exists {
+		if destination != "" {
+			split = append(split, destination)
+		}
+	}
+	if mode, exists := matchgroups["mode"]; exists {
+		if mode != "" {
+			split = append(split, mode)
+		}
+	}
+	// Fix #26329. If the destination appears to be a file, and the source is null,
+	// it may be because we've fallen through the possible naming regex and hit a
+	// situation where the user intention was to map a file into a container through
+	// a local volume, but this is not supported by the platform.
+	if matchgroups["source"] == "" && matchgroups["destination"] != "" {
+		volExp := regexp.MustCompile(`^` + rxName + `$`)
+		reservedNameExp := regexp.MustCompile(`^` + rxReservedNames + `$`)
+
+		if volExp.MatchString(matchgroups["destination"]) {
+			if reservedNameExp.MatchString(matchgroups["destination"]) {
+				return nil, fmt.Errorf("volume name %q cannot be a reserved word for Windows filenames", matchgroups["destination"])
+			}
+		} else {
+
+			exists, isDir, _ := currentFileInfoProvider.fileInfo(matchgroups["destination"])
+			if exists && !isDir {
+				return nil, fmt.Errorf("file '%s' cannot be mapped. Only directories can be mapped on this platform", matchgroups["destination"])
+
+			}
+		}
+	}
+	return split, nil
+}
+
+func parseVolumeSpecWindows(volBind string) (hostPath string, containerPath string, mode string, err error) {
+	parts, err := windowsSplitRawSpec(volBind, rxDestination)
+	if err != nil {
+		return "", "", "", fmt.Errorf("not <src>:<destination> format")
 	}
 
-	if src == "" {
+	if len(parts) < 2 {
-		return "", "", "", errors.New("missing host path")
+		return "", "", "", fmt.Errorf("not <src>:<destination> format")
 	}
 
-	if m.Destination == "" {
+	hostPath = parts[0]
-		return "", "", "", errors.New("container path is empty")
+	containerPath = parts[1]
+
+	if len(parts) > 2 {
+		mode = parts[2]
 	}
 
-	return src, m.Destination, m.Mode, nil
+	return
 }
 
 func parseVolumeSpecLinux(volBind string) (hostPath string, containerPath string, mode string, err error) {