func init() {
	flCa = flag.String([]string{"-tlscacert"}, filepath.Join(dockerConfDir, defaultCaFile), "Trust only remotes providing a certificate signed by the CA given here")
	flCert = flag.String([]string{"-tlscert"}, filepath.Join(dockerConfDir, defaultCertFile), "Path to TLS certificate file")
	flKey = flag.String([]string{"-tlskey"}, filepath.Join(dockerConfDir, defaultKeyFile), "Path to TLS key file")

	flag.Var(&flDns, []string{"#dns", "-dns"}, "Force Docker to use specific DNS servers")
	flag.Var(&flDnsSearch, []string{"-dns-search"}, "Force Docker to use specific DNS search domains")
	flag.Var(&flHosts, []string{"H", "-host"}, "The socket(s) to bind to in daemon mode\nspecified using one or more tcp://host:port, unix:///path/to/socket, fd://* or fd://socketfd.")
	flag.Var(&flGraphOpts, []string{"-storage-opt"}, "Set storage driver options")
}

func main() {
	ignoreIfaceNames := make(stringList)

	mflag.Var(&ignoreIfaceNames, []string{"-ignore-iface"}, "name of interface to ignore)")
	mflag.Parse()

	if len(mflag.Args()) < 1 {
		fmt.Fprintln(os.Stderr, "usage: netcheck [--ignore-iface <iface-name>] network-cidr")
		os.Exit(1)
	}

	cidrStr := mflag.Args()[0]
	addr, ipnet, err := net.ParseCIDR(cidrStr)
	if err != nil {
		fatal(err)
	}
	if ipnet.IP.Equal(addr) {
		err = weavenet.CheckNetworkFree(ipnet, ignoreIfaceNames)
	} else {
		err = weavenet.CheckAddressOverlap(addr, ignoreIfaceNames)
	}
	if err != nil {
		fatal(err)
	}
	os.Exit(0)
}

func init() {
	flag.BoolVar(&help, []string{"h", "-help"}, false, "Display help")
	flag.BoolVar(&verbose, []string{"v", "-verbose"}, false, "Switch to verbose output")
	flag.Var(&keys, []string{"k", "-key-file"}, "Private key with which to sign")
	flag.Parse()
	if kk := flag.Lookup("-k"); kk != nil {
		keys = *kk.Value.(*opts.ListOpts)
	}
}

func IPVar(value *net.IP, names []string, defaultValue, usage string) {
	flag.Var(NewIpOpt(value, defaultValue), names, usage)
}

func DnsSearchListVar(values *[]string, names []string, usage string) {
	flag.Var(newListOptsRef(values, ValidateDnsSearch), names, usage)
}

func IPListVar(values *[]string, names []string, usage string) {
	flag.Var(newListOptsRef(values, ValidateIPAddress), names, usage)
}

func HostListVar(values *[]string, names []string, usage string) {
	flag.Var(newListOptsRef(values, ValidateHost), names, usage)
}

func ListVar(values *[]string, names []string, usage string) {
	flag.Var(newListOptsRef(values, nil), names, usage)
}

// InstallFlags adds command-line options to the top-level flag parser for
// the current process.
func (options *Options) InstallFlags() {
	options.Mirrors = opts.NewListOpts(ValidateMirror)
	flag.Var(&options.Mirrors, []string{"-registry-mirror"}, "Preferred Docker registry mirror")
	options.InsecureRegistries = opts.NewListOpts(ValidateIndexName)
	flag.Var(&options.InsecureRegistries, []string{"-insecure-registry"}, "Enable insecure registry communication")
}

func LogOptsVar(values map[string]string, names []string, usage string) {
	flag.Var(newMapOpt(values, ValidateLogOpts), names, usage)
}

func MirrorListVar(values *[]string, names []string, usage string) {
	flag.Var(newListOptsRef(values, ValidateMirror), names, usage)
}

// LogOptsVar Defines a flag with the specified names and usage for --log-opts,
// and put the value map into MapOpt that will hold the values (key,value).
func LogOptsVar(values map[string]string, names []string, usage string) {
	flag.Var(NewMapOpts(values, nil), names, usage)
}

func MapVar(values map[string]string, names []string, usage string) {
	flag.Var(newMapOpt(values, nil), names, usage)
}

func main() {
	if len(dockerConfDir) == 0 {
		dockerConfDir = filepath.Join(os.Getenv("HOME"), ".docker")
	}
	if selfPath := utils.SelfPath(); strings.Contains(selfPath, ".dockerinit") {
		// Running in init mode
		sysinit.SysInit()
		return
	}

	var (
		flVersion            = flag.Bool([]string{"v", "-version"}, false, "Print version information and quit")
		flDaemon             = flag.Bool([]string{"d", "-daemon"}, false, "Enable daemon mode")
		flGraphOpts          opts.ListOpts
		flDebug              = flag.Bool([]string{"D", "-debug"}, false, "Enable debug mode")
		flAutoRestart        = flag.Bool([]string{"r", "-restart"}, true, "Restart previously running containers")
		bridgeName           = flag.String([]string{"b", "-bridge"}, "", "Attach containers to a pre-existing network bridge\nuse 'none' to disable container networking")
		bridgeIp             = flag.String([]string{"#bip", "-bip"}, "", "Use this CIDR notation address for the network bridge's IP, not compatible with -b")
		pidfile              = flag.String([]string{"p", "-pidfile"}, "/var/run/docker.pid", "Path to use for daemon PID file")
		flRoot               = flag.String([]string{"g", "-graph"}, "/var/lib/docker", "Path to use as the root of the Docker runtime")
		flSocketGroup        = flag.String([]string{"G", "-group"}, "docker", "Group to assign the unix socket specified by -H when running in daemon mode\nuse '' (the empty string) to disable setting of a group")
		flEnableCors         = flag.Bool([]string{"#api-enable-cors", "-api-enable-cors"}, false, "Enable CORS headers in the remote API")
		flDns                = opts.NewListOpts(opts.ValidateIPAddress)
		flDnsSearch          = opts.NewListOpts(opts.ValidateDnsSearch)
		flEnableIptables     = flag.Bool([]string{"#iptables", "-iptables"}, true, "Enable Docker's addition of iptables rules")
		flEnableIpForward    = flag.Bool([]string{"#ip-forward", "-ip-forward"}, true, "Enable net.ipv4.ip_forward")
		flDefaultIp          = flag.String([]string{"#ip", "-ip"}, "0.0.0.0", "Default IP address to use when binding container ports")
		flInterContainerComm = flag.Bool([]string{"#icc", "-icc"}, true, "Enable inter-container communication")
		flGraphDriver        = flag.String([]string{"s", "-storage-driver"}, "", "Force the Docker runtime to use a specific storage driver")
		flExecDriver         = flag.String([]string{"e", "-exec-driver"}, "native", "Force the Docker runtime to use a specific exec driver")
		flHosts              = opts.NewListOpts(api.ValidateHost)
		flMtu                = flag.Int([]string{"#mtu", "-mtu"}, 0, "Set the containers network MTU\nif no value is provided: default to the default route MTU or 1500 if no default route is available")
		flTls                = flag.Bool([]string{"-tls"}, false, "Use TLS; implied by tls-verify flags")
		flTlsVerify          = flag.Bool([]string{"-tlsverify"}, false, "Use TLS and verify the remote (daemon: verify client, client: verify daemon)")
		flCa                 = flag.String([]string{"-tlscacert"}, filepath.Join(dockerConfDir, defaultCaFile), "Trust only remotes providing a certificate signed by the CA given here")
		flCert               = flag.String([]string{"-tlscert"}, filepath.Join(dockerConfDir, defaultCertFile), "Path to TLS certificate file")
		flKey                = flag.String([]string{"-tlskey"}, filepath.Join(dockerConfDir, defaultKeyFile), "Path to TLS key file")
		flSelinuxEnabled     = flag.Bool([]string{"-selinux-enabled"}, false, "Enable selinux support. SELinux does not presently support the BTRFS storage driver")
	)
	flag.Var(&flDns, []string{"#dns", "-dns"}, "Force Docker to use specific DNS servers")
	flag.Var(&flDnsSearch, []string{"-dns-search"}, "Force Docker to use specific DNS search domains")
	flag.Var(&flHosts, []string{"H", "-host"}, "The socket(s) to bind to in daemon mode\nspecified using one or more tcp://host:port, unix:///path/to/socket, fd://* or fd://socketfd.")
	flag.Var(&flGraphOpts, []string{"-storage-opt"}, "Set storage driver options")

	flag.Parse()

	if *flVersion {
		showVersion()
		return
	}
	if flHosts.Len() == 0 {
		defaultHost := os.Getenv("DOCKER_HOST")

		if defaultHost == "" || *flDaemon {
			// If we do not have a host, default to unix socket
			defaultHost = fmt.Sprintf("unix://%s", api.DEFAULTUNIXSOCKET)
		}
		if _, err := api.ValidateHost(defaultHost); err != nil {
			log.Fatal(err)
		}
		flHosts.Set(defaultHost)
	}

	if *bridgeName != "" && *bridgeIp != "" {
		log.Fatal("You specified -b & --bip, mutually exclusive options. Please specify only one.")
	}

	if !*flEnableIptables && !*flInterContainerComm {
		log.Fatal("You specified --iptables=false with --icc=false. ICC uses iptables to function. Please set --icc or --iptables to true.")
	}

	if net.ParseIP(*flDefaultIp) == nil {
		log.Fatalf("Specified --ip=%s is not in correct format \"0.0.0.0\".", *flDefaultIp)
	}

	if *flDebug {
		os.Setenv("DEBUG", "1")
	}

	if *flDaemon {
		if runtime.GOOS != "linux" {
			log.Fatalf("The Docker daemon is only supported on linux")
		}
		if os.Geteuid() != 0 {
			log.Fatalf("The Docker daemon needs to be run as root")
		}

		if flag.NArg() != 0 {
			flag.Usage()
			return
		}

		// set up the TempDir to use a canonical path
		tmp := os.TempDir()
		realTmp, err := utils.ReadSymlinkedDirectory(tmp)
		if err != nil {
			log.Fatalf("Unable to get the full path to the TempDir (%s): %s", tmp, err)
		}
		os.Setenv("TMPDIR", realTmp)

//.........这里部分代码省略.........

func LabelListVar(values *[]string, names []string, usage string) {
	flag.Var(newListOptsRef(values, ValidateLabel), names, usage)
}

func UlimitMapVar(values map[string]*ulimit.Ulimit, names []string, usage string) {
	flag.Var(NewUlimitOpt(values), names, usage)
}

func ListVar(p *[]string, names []string, value []string, usage string) {
	*p = value
	mflag.Var(&listOpts{p, false}, names, usage)
}