Refactor build/runBuild()

[thaJeztah]

Per the discussion in #231 (comment), the runBuild() function in cli/command/image/build.go is getting quite long, and may need a refactor

[AkihiroSuda]

Is this closable now?

[thaJeztah]

I guess this is to be replaced with the buildkit equivalent, so we should look if that one needs refactoring;

cli/cli/command/image/build_buildkit.go

Lines 43 to 189 in ab50c2f

	func runBuildBuildKit(dockerCli command.Cli, options buildOptions) error {
	ctx := appcontext.Context()
	s, err := trySession(dockerCli, options.context)
	if err != nil {
	return err
	}
	if s == nil {
	return errors.Errorf("buildkit not supported by daemon")
	}
	if options.imageIDFile != "" {
	// Avoid leaving a stale file if we eventually fail
	if err := os.Remove(options.imageIDFile); err != nil && !os.IsNotExist(err) {
	return errors.Wrap(err, "removing image ID file")
	}
	}
	var (
	remote string
	body io.Reader
	dockerfileName = options.dockerfileName
	dockerfileReader io.ReadCloser
	dockerfileDir string
	contextDir string
	)
	switch {
	case options.contextFromStdin():
	if options.dockerfileFromStdin() {
	return errStdinConflict
	}
	rc, isArchive, err := build.DetectArchiveReader(os.Stdin)
	if err != nil {
	return err
	}
	if isArchive {
	body = rc
	remote = uploadRequestRemote
	} else {
	if options.dockerfileName != "" {
	return errDockerfileConflict
	}
	dockerfileReader = rc
	remote = clientSessionRemote
	// TODO: make fssync handle empty contextdir
	contextDir, _ = ioutil.TempDir("", "empty-dir")
	defer os.RemoveAll(contextDir)
	}
	case isLocalDir(options.context):
	contextDir = options.context
	if options.dockerfileFromStdin() {
	dockerfileReader = os.Stdin
	} else if options.dockerfileName != "" {
	dockerfileName = filepath.Base(options.dockerfileName)
	dockerfileDir = filepath.Dir(options.dockerfileName)
	} else {
	dockerfileDir = options.context
	}
	remote = clientSessionRemote
	case urlutil.IsGitURL(options.context):
	remote = options.context
	case urlutil.IsURL(options.context):
	remote = options.context
	default:
	return errors.Errorf("unable to prepare context: path %q not found", options.context)
	}
	if dockerfileReader != nil {
	dockerfileName = build.DefaultDockerfileName
	dockerfileDir, err = build.WriteTempDockerfile(dockerfileReader)
	if err != nil {
	return err
	}
	defer os.RemoveAll(dockerfileDir)
	}
	if dockerfileDir != "" {
	s.Allow(filesync.NewFSSyncProvider([]filesync.SyncedDir{
	{
	Name: "context",
	Dir: contextDir,
	Map: resetUIDAndGID,
	},
	{
	Name: "dockerfile",
	Dir: dockerfileDir,
	},
	}))
	}
	s.Allow(authprovider.NewDockerAuthProvider())
	if len(options.secrets) > 0 {
	sp, err := parseSecretSpecs(options.secrets)
	if err != nil {
	return errors.Wrapf(err, "could not parse secrets: %v", options.secrets)
	}
	s.Allow(sp)
	}
	if len(options.ssh) > 0 {
	sshp, err := parseSSHSpecs(options.ssh)
	if err != nil {
	return errors.Wrapf(err, "could not parse ssh: %v", options.ssh)
	}
	s.Allow(sshp)
	}
	eg, ctx := errgroup.WithContext(ctx)
	eg.Go(func() error {
	return s.Run(context.TODO(), dockerCli.Client().DialSession)
	})
	buildID := stringid.GenerateRandomID()
	if body != nil {
	eg.Go(func() error {
	buildOptions := types.ImageBuildOptions{
	Version: types.BuilderBuildKit,
	BuildID: uploadRequestRemote + ":" + buildID,
	}
	response, err := dockerCli.Client().ImageBuild(context.Background(), body, buildOptions)
	if err != nil {
	return err
	}
	defer response.Body.Close()
	return nil
	})
	}
	eg.Go(func() error {
	defer func() { // make sure the Status ends cleanly on build errors
	s.Close()
	}()
	buildOptions := imageBuildOptions(dockerCli, options)
	buildOptions.Version = types.BuilderBuildKit
	buildOptions.Dockerfile = dockerfileName
	//buildOptions.AuthConfigs = authConfigs // handled by session
	buildOptions.RemoteContext = remote
	buildOptions.SessionID = s.ID()
	buildOptions.BuildID = buildID
	return doBuild(ctx, eg, dockerCli, options, buildOptions)
	})
	return eg.Wait()
	}

, but otherwise; yes, I think we should close for now