Function copyFromContainer

cli/command/container/cp.go:257–349

(ctx context.Context, dockerCLI command.Cli, copyConfig cpConfig)

}

func copyFromContainer(ctx context.Context, dockerCLI command.Cli, copyConfig cpConfig) (err error) {
	dstPath := copyConfig.destPath
	srcPath := copyConfig.sourcePath

	if dstPath != "-" {
		// Get an absolute destination path.
		dstPath, err = resolveLocalPath(dstPath)
		if err != nil {
			return err
		}
	}

	if err := command.ValidateOutputPath(dstPath); err != nil {
		return err
	}

	apiClient := dockerCLI.Client()
	// if client requests to follow symlinks, then must decide target file to be copied
	var rebaseName string
	if copyConfig.followLink {
		src, err := apiClient.ContainerStatPath(ctx, copyConfig.container, client.ContainerStatPathOptions{
			Path: srcPath,
		})

		// If the destination is a symbolic link, we should follow it.
		if err == nil && src.Stat.Mode&os.ModeSymlink != 0 {
			linkTarget := src.Stat.LinkTarget
			if !isAbs(linkTarget) {
				// Join with the parent directory.
				srcParent, _ := archive.SplitPathDirEntry(srcPath)
				linkTarget = filepath.Join(srcParent, linkTarget)
			}

			linkTarget, rebaseName = archive.GetRebaseName(srcPath, linkTarget)
			srcPath = linkTarget
		}
	}

	ctx, cancel := signal.NotifyContext(ctx, os.Interrupt)
	defer cancel()

	cpRes, err := apiClient.CopyFromContainer(ctx, copyConfig.container, client.CopyFromContainerOptions{
		SourcePath: srcPath,
	})
	if err != nil {
		return err
	}
	content := cpRes.Content
	defer func() { _ = content.Close() }()

	if dstPath == "-" {
		_, err = io.Copy(dockerCLI.Out(), content)
		return err
	}

	srcInfo := archive.CopyInfo{
		Path:       srcPath,
		Exists:     true,