func main()

in tools/build_tar/buildtar.go [40:147]
86 lines of code
16 McCabe index (conditional complexity)

func main() {
	var (
		flagfile string

		output      string
		directory   string
		compression string

		files multiString
		tars  multiString
		debs  multiString
		links multiString

		mode  string
		modes multiString

		owner      string
		owners     multiString
		ownerName  string
		ownerNames multiString

		mtime string
	)

	flag.StringVar(&flagfile, "flagfile", "", "Path to flagfile")

	flag.StringVar(&output, "output", "", "The output file, mandatory")
	flag.StringVar(&directory, "directory", "", "Directory in which to store the file inside the layer")
	flag.StringVar(&compression, "compression", "", "Compression (`gz` or `bz2`), default is none.")

	flag.Var(&files, "file", "A file to add to the layer")
	flag.Var(&tars, "tar", "A tar file to add to the layer")
	flag.Var(&debs, "deb", "A debian package to add to the layer")
	flag.Var(&links, "link", "Add a symlink a inside the layer ponting to b if a:b is specified")

	flag.StringVar(&mode, "mode", "", "Force the mode on the added files (in octal).")
	flag.Var(&modes, "modes", "Specific mode to apply to specific file (from the file argument), e.g., path/to/file=0455.")

	flag.StringVar(&owner, "owner", "0.0", "Specify the numeric default owner of all files, e.g., 0.0")
	flag.Var(&owners, "owners", "Specify the numeric owners of individual files, e.g. path/to/file=0.0.")
	flag.StringVar(&ownerName, "owner_name", "", "Specify the owner name of all files, e.g. root.root.")
	flag.Var(&ownerNames, "owner_names", "Specify the owner names of individual files, e.g. path/to/file=root.root.")

	flag.StringVar(&mtime, "mtime", "",
		"mtime to set on tar file entries. May be an integer (corresponding to epoch seconds) or the value \"portable\", which will use the value 2000-01-01, usable with non *nix OSes")

	flag.Set("logtostderr", "true")

	flag.Parse()

	if flagfile != "" {
		b, err := ioutil.ReadFile(flagfile)
		if err != nil {
			klog.Fatalf("couldn't read flagfile: %v", err)
		}
		cmdline := strings.Split(string(b), "\n")
		flag.CommandLine.Parse(cmdline)
	}

	if output == "" {
		klog.Fatalf("--output flag is required")
	}

	parsedMtime, err := parseMtimeFlag(mtime)
	if err != nil {
		klog.Fatalf("invalid value for --mtime: %s", mtime)
	}

	meta := newFileMeta(mode, modes, owner, owners, ownerName, ownerNames, parsedMtime)

	tf, err := newTarFile(output, directory, compression, meta)
	if err != nil {
		klog.Fatalf("couldn't build tar: %v", err)
	}
	defer tf.Close()

	for _, file := range files {
		parts := strings.SplitN(file, "=", 2)
		if len(parts) != 2 {
			klog.Fatalf("bad parts length for file %q", file)
		}
		if err := tf.addFile(parts[0], parts[1]); err != nil {
			klog.Fatalf("couldn't add file: %v", err)
		}
	}

	for _, tar := range tars {
		if err := tf.addTar(tar); err != nil {
			klog.Fatalf("couldn't add tar: %v", err)
		}
	}

	for _, deb := range debs {
		if err := tf.addDeb(deb); err != nil {
			klog.Fatalf("couldn't add deb: %v", err)
		}
	}

	for _, link := range links {
		parts := strings.SplitN(link, ":", 2)
		if len(parts) != 2 {
			klog.Fatalf("bad parts length for link %q", link)
		}
		if err := tf.addLink(parts[0], parts[1]); err != nil {
			klog.Fatalf("couldn't add link: %v", err)
		}
	}
}