Initial commit

vendor/github.com/hyperhq/hypercli/api/client/cp.go

@@ -0,0 +1,297 @@
+package client
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"golang.org/x/net/context"
+
+	"github.com/docker/engine-api/types"
+	Cli "github.com/hyperhq/hypercli/cli"
+	"github.com/hyperhq/hypercli/pkg/archive"
+	flag "github.com/hyperhq/hypercli/pkg/mflag"
+	"github.com/hyperhq/hypercli/pkg/system"
+)
+
+type copyDirection int
+
+const (
+	fromContainer copyDirection = (1 << iota)
+	toContainer
+	acrossContainers = fromContainer | toContainer
+)
+
+type cpConfig struct {
+	followLink bool
+}
+
+// CmdCp copies files/folders to or from a path in a container.
+//
+// When copying from a container, if DEST_PATH is '-' the data is written as a
+// tar archive file to STDOUT.
+//
+// When copying to a container, if SRC_PATH is '-' the data is read as a tar
+// archive file from STDIN, and the destination CONTAINER:DEST_PATH, must specify
+// a directory.
+//
+// Usage:
+// 	docker cp CONTAINER:SRC_PATH DEST_PATH|-
+// 	docker cp SRC_PATH|- CONTAINER:DEST_PATH
+func (cli *DockerCli) Cp(args ...string) error {
+	cmd := Cli.Subcmd(
+		"cp",
+		[]string{"CONTAINER:SRC_PATH DEST_PATH|-", "SRC_PATH|- CONTAINER:DEST_PATH"},
+		strings.Join([]string{
+			Cli.DockerCommands["cp"].Description,
+			"\nUse '-' 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,
+	)
+
+	followLink := cmd.Bool([]string{"L", "-follow-link"}, false, "Always follow symbol link in SRC_PATH")
+
+	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
+	}
+
+	cpParam := &cpConfig{
+		followLink: *followLink,
+	}
+
+	ctx := context.Background()
+
+	switch direction {
+	case fromContainer:
+		return cli.copyFromContainer(ctx, srcContainer, srcPath, dstPath, cpParam)
+	case toContainer:
+		return cli.copyToContainer(ctx, srcPath, dstContainer, dstPath, cpParam)
+	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 system.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(ctx context.Context, containerName, path string) (types.ContainerPathStat, error) {
+	return cli.client.ContainerStatPath(ctx, containerName, path)
+}
+
+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(ctx context.Context, srcContainer, srcPath, dstPath string, cpParam *cpConfig) (err error) {
+	if dstPath != "-" {
+		// Get an absolute destination path.
+		dstPath, err = resolveLocalPath(dstPath)
+		if err != nil {
+			return err
+		}
+	}
+
+	// if client requests to follow symbol link, then must decide target file to be copied
+	var rebaseName string
+	if cpParam.followLink {
+		srcStat, err := cli.statContainerPath(ctx, srcContainer, srcPath)
+
+		// If the destination is a symbolic link, we should follow it.
+		if err == nil && srcStat.Mode&os.ModeSymlink != 0 {
+			linkTarget := srcStat.LinkTarget
+			if !system.IsAbs(linkTarget) {
+				// Join with the parent directory.
+				srcParent, _ := archive.SplitPathDirEntry(srcPath)
+				linkTarget = filepath.Join(srcParent, linkTarget)
+			}
+
+			linkTarget, rebaseName = archive.GetRebaseName(srcPath, linkTarget)
+			srcPath = linkTarget
+		}
+
+	}
+
+	content, stat, err := cli.client.CopyFromContainer(ctx, srcContainer, srcPath)
+	if err != nil {
+		return err
+	}
+	defer content.Close()
+
+	if dstPath == "-" {
+		// Send the response to STDOUT.
+		_, err = io.Copy(os.Stdout, content)
+
+		return err
+	}
+
+	// Prepare source copy info.
+	srcInfo := archive.CopyInfo{
+		Path:       srcPath,
+		Exists:     true,
+		IsDir:      stat.Mode.IsDir(),
+		RebaseName: rebaseName,
+	}
+
+	preArchive := content
+	if len(srcInfo.RebaseName) != 0 {
+		_, srcBase := archive.SplitPathDirEntry(srcInfo.Path)
+		preArchive = archive.RebaseArchiveEntries(content, srcBase, srcInfo.RebaseName)
+	}
+	// 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(preArchive, srcInfo, dstPath)
+}
+
+func (cli *DockerCli) copyToContainer(ctx context.Context, srcPath, dstContainer, dstPath string, cpParam *cpConfig) (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(ctx, 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 !system.IsAbs(linkTarget) {
+			// Join with the parent directory.
+			dstParent, _ := archive.SplitPathDirEntry(dstPath)
+			linkTarget = filepath.Join(dstParent, linkTarget)
+		}
+
+		dstInfo.Path = linkTarget
+		dstStat, err = cli.statContainerPath(ctx, 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 versa) 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, cpParam.followLink)
+		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 desired
+		// 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
+	}
+
+	options := types.CopyToContainerOptions{
+		AllowOverwriteDirWithFile: false,
+	}
+
+	return cli.client.CopyToContainer(ctx, dstContainer, resolvedDstPath, content, options)
+}