//  This Helper will initialize a test in-memory DB.
func createTestDb(t *testing.T) (db *sql.DB) {
	// Setup logging if main() hasn't been called/when testing
	if shared.Log == nil {
		var err error
		shared.Log, err = logging.GetLogger("", "", true, true, nil)
		if err != nil {
			t.Fatal(err)
		}
	}

	var err error
	d := &Daemon{MockMode: true}
	err = initializeDbObject(d, ":memory:")
	db = d.db

	if err != nil {
		t.Fatal(err)
	}

	_, err = db.Exec(DB_FIXTURES)
	if err != nil {
		t.Fatal(err)
	}
	return // db is a named output param
}

func (d *Daemon) Init() error {
	d.shutdownChan = make(chan bool)

	/* Set the executable path */
	absPath, err := os.Readlink("/proc/self/exe")
	if err != nil {
		return err
	}
	d.execPath = absPath

	/* Set the LVM environment */
	err = os.Setenv("LVM_SUPPRESS_FD_WARNINGS", "1")
	if err != nil {
		return err
	}

	/* Setup logging if that wasn't done before */
	if shared.Log == nil {
		shared.Log, err = logging.GetLogger("", "", true, true, nil)
		if err != nil {
			return err
		}
	}

	if !d.IsMock {
		shared.Log.Info("LXD is starting",
			log.Ctx{"path": shared.VarPath("")})
	} else {
		shared.Log.Info("Mock LXD is starting",
			log.Ctx{"path": shared.VarPath("")})
	}

	/* Detect user namespaces */
	runningInUserns = shared.RunningInUserNS()

	/* Detect AppArmor support */
	if aaAvailable && os.Getenv("LXD_SECURITY_APPARMOR") == "false" {
		aaAvailable = false
		aaAdmin = false
		shared.Log.Warn("AppArmor support has been manually disabled")
	}

	if aaAvailable && !shared.IsDir("/sys/kernel/security/apparmor") {
		aaAvailable = false
		aaAdmin = false
		shared.Log.Warn("AppArmor support has been disabled because of lack of kernel support")
	}

	_, err = exec.LookPath("apparmor_parser")
	if aaAvailable && err != nil {
		aaAvailable = false
		aaAdmin = false
		shared.Log.Warn("AppArmor support has been disabled because 'apparmor_parser' couldn't be found")
	}

	/* Detect AppArmor admin support */
	if aaAdmin && !haveMacAdmin() {
		aaAdmin = false
		shared.Log.Warn("Per-container AppArmor profiles are disabled because the mac_admin capability is missing.")
	}

	if aaAdmin && runningInUserns {
		aaAdmin = false
		shared.Log.Warn("Per-container AppArmor profiles are disabled because LXD is running in an unprivileged container.")
	}

	/* Detect AppArmor confinment */
	if !aaConfined {
		profile := aaProfile()
		if profile != "unconfined" && profile != "" {
			aaConfined = true
			shared.Log.Warn("Per-container AppArmor profiles are disabled because LXD is already protected by AppArmor.")
		}
	}

	/* Detect CGroup support */
	cgCpuController = shared.PathExists("/sys/fs/cgroup/cpu/")
	if !cgCpuController {
		shared.Log.Warn("Couldn't find the CGroup CPU controller, CPU time limits will be ignored.")
	}

	cgCpusetController = shared.PathExists("/sys/fs/cgroup/cpuset/")
	if !cgCpusetController {
		shared.Log.Warn("Couldn't find the CGroup CPUset controller, CPU pinning will be ignored.")
	}

	cgMemoryController = shared.PathExists("/sys/fs/cgroup/memory/")
	if !cgMemoryController {
		shared.Log.Warn("Couldn't find the CGroup memory controller, memory limits will be ignored.")
	}

	cgSwapAccounting = shared.PathExists("/sys/fs/cgroup/memory/memory.memsw.limit_in_bytes")
	if !cgSwapAccounting {
		shared.Log.Warn("CGroup memory swap accounting is disabled, swap limits will be ignored.")
	}

	/* Get the list of supported architectures */
	var architectures = []int{}

	uname := syscall.Utsname{}
//.........这里部分代码省略.........

func run() error {
	verbose := gnuflag.Bool("verbose", false, i18n.G("Enables verbose mode."))
	debug := gnuflag.Bool("debug", false, i18n.G("Enables debug mode."))
	forceLocal := gnuflag.Bool("force-local", false, i18n.G("Force using the local unix socket."))
	noAlias := gnuflag.Bool("no-alias", false, i18n.G("Ignore aliases when determining what command to run."))

	configDir := "$HOME/.config/lxc"
	if os.Getenv("LXD_CONF") != "" {
		configDir = os.Getenv("LXD_CONF")
	}
	configPath = os.ExpandEnv(path.Join(configDir, "config.yml"))

	if len(os.Args) >= 3 && os.Args[1] == "config" && os.Args[2] == "profile" {
		fmt.Fprintf(os.Stderr, i18n.G("`lxc config profile` is deprecated, please use `lxc profile`")+"\n")
		os.Args = append(os.Args[:1], os.Args[2:]...)
	}

	if len(os.Args) >= 2 && (os.Args[1] == "-h" || os.Args[1] == "--help") {
		os.Args[1] = "help"
	}

	if len(os.Args) >= 2 && (os.Args[1] == "--all") {
		os.Args[1] = "help"
		os.Args = append(os.Args, "--all")
	}

	if len(os.Args) == 2 && os.Args[1] == "--version" {
		os.Args[1] = "version"
	}

	if len(os.Args) < 2 {
		commands["help"].run(nil, nil)
		os.Exit(1)
	}

	var config *lxd.Config
	var err error

	if *forceLocal {
		config = &lxd.DefaultConfig
	} else {
		config, err = lxd.LoadConfig(configPath)
		if err != nil {
			return err
		}
	}

	// This is quite impolite, but it seems gnuflag needs us to shift our
	// own exename out of the arguments before parsing them. However, this
	// is useful for execIfAlias, which wants to know exactly the command
	// line we received, and in some cases is called before this shift, and
	// in others after. So, let's save the original args.
	origArgs := os.Args
	name := os.Args[1]

	/* at this point we haven't parsed the args, so we have to look for
	 * --no-alias by hand.
	 */
	if !shared.StringInSlice("--no-alias", origArgs) {
		execIfAliases(config, origArgs)
	}
	cmd, ok := commands[name]
	if !ok {
		commands["help"].run(nil, nil)
		fmt.Fprintf(os.Stderr, "\n"+i18n.G("error: unknown command: %s")+"\n", name)
		os.Exit(1)
	}
	cmd.flags()
	gnuflag.Usage = func() {
		fmt.Fprintf(os.Stderr, i18n.G("Usage: %s")+"\n\n"+i18n.G("Options:")+"\n\n", strings.TrimSpace(cmd.usage()))
		gnuflag.PrintDefaults()
	}

	os.Args = os.Args[1:]
	gnuflag.Parse(true)

	shared.Log, err = logging.GetLogger("", "", *verbose, *debug, nil)
	if err != nil {
		return err
	}

	certf := config.ConfigPath("client.crt")
	keyf := config.ConfigPath("client.key")

	if !*forceLocal && os.Args[0] != "help" && os.Args[0] != "version" && (!shared.PathExists(certf) || !shared.PathExists(keyf)) {
		fmt.Fprintf(os.Stderr, i18n.G("Generating a client certificate. This may take a minute...")+"\n")

		err = shared.FindOrGenCert(certf, keyf)
		if err != nil {
			return err
		}
	}

	err = cmd.run(config, gnuflag.Args())
	if err == errArgs {
		/* If we got an error about invalid arguments, let's try to
		 * expand this as an alias
		 */
		if !*noAlias {
			execIfAliases(config, origArgs)
//.........这里部分代码省略.........

//.........这里部分代码省略.........
		fmt.Printf("    forkexec\n")
		fmt.Printf("        Execute a command in a container\n")
		fmt.Printf("    forkgetnet\n")
		fmt.Printf("        Get container network information\n")
		fmt.Printf("    forkgetfile\n")
		fmt.Printf("        Grab a file from a running container\n")
		fmt.Printf("    forkmigrate\n")
		fmt.Printf("        Restore a container after migration\n")
		fmt.Printf("    forkputfile\n")
		fmt.Printf("        Push a file to a running container\n")
		fmt.Printf("    forkstart\n")
		fmt.Printf("        Start a container\n")
		fmt.Printf("    callhook\n")
		fmt.Printf("        Call a container hook\n")
	}

	// Parse the arguments
	gnuflag.Parse(true)

	// Set the global variables
	debug = *argDebug
	verbose = *argVerbose

	if *argHelp {
		// The user asked for help via --help, so we shouldn't print to
		// stderr.
		gnuflag.SetOut(os.Stdout)
		gnuflag.Usage()
		return nil
	}

	// Deal with --version right here
	if *argVersion {
		fmt.Println(shared.Version)
		return nil
	}

	if len(shared.VarPath("unix.sock")) > 107 {
		return fmt.Errorf("LXD_DIR is too long, must be < %d", 107-len("unix.sock"))
	}

	// Configure logging
	syslog := ""
	if *argSyslog {
		syslog = "lxd"
	}

	handler := eventsHandler{}
	var err error
	shared.Log, err = logging.GetLogger(syslog, *argLogfile, *argVerbose, *argDebug, handler)
	if err != nil {
		fmt.Printf("%s", err)
		return nil
	}

	// Process sub-commands
	if len(os.Args) > 1 {
		// "forkputfile", "forkgetfile", "forkmount" and "forkumount" are handled specially in nsexec.go
		// "forkgetnet" is partially handled in nsexec.go (setns)
		switch os.Args[1] {
		// Main commands
		case "activateifneeded":
			return cmdActivateIfNeeded()
		case "daemon":
			return cmdDaemon()
		case "callhook":
			return cmdCallHook(os.Args[1:])
		case "init":
			return cmdInit()
		case "ready":
			return cmdReady()
		case "shutdown":
			return cmdShutdown()
		case "waitready":
			return cmdWaitReady()

		// Internal commands
		case "forkgetnet":
			return printnet()
		case "forkmigrate":
			return MigrateContainer(os.Args[1:])
		case "forkstart":
			return startContainer(os.Args[1:])
		case "forkexec":
			ret, err := execContainer(os.Args[1:])
			if err != nil {
				fmt.Fprintf(os.Stderr, "error: %v\n", err)
			}
			os.Exit(ret)
		}
	}

	// Fail if some other command is passed
	if gnuflag.NArg() > 0 {
		gnuflag.Usage()
		return fmt.Errorf("Unknown arguments")
	}

	return cmdDaemon()
}

func run() error {
	verbose := gnuflag.Bool("verbose", false, i18n.G("Enables verbose mode."))
	debug := gnuflag.Bool("debug", false, i18n.G("Enables debug mode."))
	forceLocal := gnuflag.Bool("force-local", false, i18n.G("Force using the local unix socket."))
	noAlias := gnuflag.Bool("no-alias", false, i18n.G("Ignore aliases when determining what command to run."))

	configDir := "$HOME/.config/lxc"
	if os.Getenv("LXD_CONF") != "" {
		configDir = os.Getenv("LXD_CONF")
	}
	configPath = os.ExpandEnv(path.Join(configDir, "config.yml"))

	if len(os.Args) >= 3 && os.Args[1] == "config" && os.Args[2] == "profile" {
		fmt.Fprintf(os.Stderr, i18n.G("`lxc config profile` is deprecated, please use `lxc profile`")+"\n")
		os.Args = append(os.Args[:1], os.Args[2:]...)
	}

	if len(os.Args) >= 2 && (os.Args[1] == "-h" || os.Args[1] == "--help") {
		os.Args[1] = "help"
	}

	if len(os.Args) >= 2 && (os.Args[1] == "--all") {
		os.Args[1] = "help"
		os.Args = append(os.Args, "--all")
	}

	if len(os.Args) == 2 && os.Args[1] == "--version" {
		os.Args[1] = "version"
	}

	if len(os.Args) == 2 && os.Args[1] == "--man" {
		os.Args[1] = "manpage"
	}

	if len(os.Args) < 2 {
		commands["help"].run(nil, nil)
		os.Exit(1)
	}

	var config *lxd.Config
	var err error

	if *forceLocal {
		config = &lxd.DefaultConfig
	} else {
		config, err = lxd.LoadConfig(configPath)
		if err != nil {
			return err
		}
	}

	// This is quite impolite, but it seems gnuflag needs us to shift our
	// own exename out of the arguments before parsing them. However, this
	// is useful for execIfAlias, which wants to know exactly the command
	// line we received, and in some cases is called before this shift, and
	// in others after. So, let's save the original args.
	origArgs := os.Args
	name := os.Args[1]

	/* at this point we haven't parsed the args, so we have to look for
	 * --no-alias by hand.
	 */
	if !shared.StringInSlice("--no-alias", origArgs) {
		execIfAliases(config, origArgs)
	}
	cmd, ok := commands[name]
	if !ok {
		commands["help"].run(nil, nil)
		fmt.Fprintf(os.Stderr, "\n"+i18n.G("error: unknown command: %s")+"\n", name)
		os.Exit(1)
	}
	cmd.flags()
	gnuflag.Usage = func() {
		fmt.Fprintf(os.Stderr, i18n.G("Usage: %s")+"\n\n"+i18n.G("Options:")+"\n\n", strings.TrimSpace(cmd.usage()))
		gnuflag.PrintDefaults()
	}

	os.Args = os.Args[1:]
	gnuflag.Parse(true)

	shared.Log, err = logging.GetLogger("", "", *verbose, *debug, nil)
	if err != nil {
		return err
	}

	// If the user is running a command that may attempt to connect to the local daemon
	// and this is the first time the client has been run by the user, then check to see
	// if LXD has been properly configured.  Don't display the message if the var path
	// does not exist (LXD not installed), as the user may be targeting a remote daemon.
	if os.Args[0] != "help" && os.Args[0] != "version" && shared.PathExists(shared.VarPath("")) && !shared.PathExists(config.ConfigDir) {

		// Create the config dir so that we don't get in here again for this user.
		err = os.MkdirAll(config.ConfigDir, 0750)
		if err != nil {
			return err
		}

		fmt.Fprintf(os.Stderr, i18n.G("If this is your first time using LXD, you should also run: sudo lxd init")+"\n")
		fmt.Fprintf(os.Stderr, i18n.G("To start your first container, try: lxc launch ubuntu:16.04")+"\n\n")
	}
//.........这里部分代码省略.........

func (d *Daemon) Init() error {
	/* Initialize some variables */
	d.imagesDownloading = map[string]chan bool{}

	d.readyChan = make(chan bool)
	d.shutdownChan = make(chan bool)

	/* Set the executable path */
	absPath, err := os.Readlink("/proc/self/exe")
	if err != nil {
		return err
	}
	d.execPath = absPath

	/* Set the LVM environment */
	err = os.Setenv("LVM_SUPPRESS_FD_WARNINGS", "1")
	if err != nil {
		return err
	}

	/* Setup logging if that wasn't done before */
	if shared.Log == nil {
		shared.Log, err = logging.GetLogger("", "", true, true, nil)
		if err != nil {
			return err
		}
	}

	/* Print welcome message */
	if d.MockMode {
		shared.Log.Info("LXD is starting in mock mode",
			log.Ctx{"path": shared.VarPath("")})
	} else if d.SetupMode {
		shared.Log.Info("LXD is starting in setup mode",
			log.Ctx{"path": shared.VarPath("")})
	} else {
		shared.Log.Info("LXD is starting in normal mode",
			log.Ctx{"path": shared.VarPath("")})
	}

	/* Detect user namespaces */
	runningInUserns = shared.RunningInUserNS()

	/* Detect AppArmor support */
	if aaAvailable && os.Getenv("LXD_SECURITY_APPARMOR") == "false" {
		aaAvailable = false
		aaAdmin = false
		shared.Log.Warn("AppArmor support has been manually disabled")
	}

	if aaAvailable && !shared.IsDir("/sys/kernel/security/apparmor") {
		aaAvailable = false
		aaAdmin = false
		shared.Log.Warn("AppArmor support has been disabled because of lack of kernel support")
	}

	_, err = exec.LookPath("apparmor_parser")
	if aaAvailable && err != nil {
		aaAvailable = false
		aaAdmin = false
		shared.Log.Warn("AppArmor support has been disabled because 'apparmor_parser' couldn't be found")
	}

	/* Detect AppArmor admin support */
	if aaAdmin && !haveMacAdmin() {
		aaAdmin = false
		shared.Log.Warn("Per-container AppArmor profiles are disabled because the mac_admin capability is missing.")
	}

	if aaAdmin && runningInUserns {
		aaAdmin = false
		shared.Log.Warn("Per-container AppArmor profiles are disabled because LXD is running in an unprivileged container.")
	}

	/* Detect AppArmor confinment */
	if !aaConfined {
		profile := aaProfile()
		if profile != "unconfined" && profile != "" {
			aaConfined = true
			shared.Log.Warn("Per-container AppArmor profiles are disabled because LXD is already protected by AppArmor.")
		}
	}

	/* Detect CGroup support */
	cgBlkioController = shared.PathExists("/sys/fs/cgroup/blkio/")
	if !cgBlkioController {
		shared.Log.Warn("Couldn't find the CGroup blkio controller, I/O limits will be ignored.")
	}

	cgCpuController = shared.PathExists("/sys/fs/cgroup/cpu/")
	if !cgCpuController {
		shared.Log.Warn("Couldn't find the CGroup CPU controller, CPU time limits will be ignored.")
	}

	cgCpusetController = shared.PathExists("/sys/fs/cgroup/cpuset/")
	if !cgCpusetController {
		shared.Log.Warn("Couldn't find the CGroup CPUset controller, CPU pinning will be ignored.")
	}

	cgDevicesController = shared.PathExists("/sys/fs/cgroup/devices/")
//.........这里部分代码省略.........

func run() error {
	verbose := gnuflag.Bool("verbose", false, i18n.G("Enables verbose mode."))
	debug := gnuflag.Bool("debug", false, i18n.G("Enables debug mode."))
	forceLocal := gnuflag.Bool("force-local", false, i18n.G("Force using the local unix socket."))

	configDir := os.Getenv("LXD_CONF")
	if configDir != "" {
		lxd.ConfigDir = configDir
	}

	if len(os.Args) >= 3 && os.Args[1] == "config" && os.Args[2] == "profile" {
		fmt.Fprintf(os.Stderr, i18n.G("`lxc config profile` is deprecated, please use `lxc profile`")+"\n")
		os.Args = append(os.Args[:1], os.Args[2:]...)
	}

	if len(os.Args) >= 2 && (os.Args[1] == "-h" || os.Args[1] == "--help") {
		os.Args[1] = "help"
	}

	if len(os.Args) >= 2 && (os.Args[1] == "--all") {
		os.Args[1] = "help"
		os.Args = append(os.Args, "--all")
	}

	if len(os.Args) == 2 && os.Args[1] == "--version" {
		os.Args[1] = "version"
	}

	if len(os.Args) < 2 {
		commands["help"].run(nil, nil)
		os.Exit(1)
	}

	var config *lxd.Config
	var err error

	if *forceLocal {
		config = &lxd.DefaultConfig
	} else {
		config, err = lxd.LoadConfig()
		if err != nil {
			return err
		}

		// One time migration from old config
		if config.DefaultRemote == "" {
			_, ok := config.Remotes["local"]
			if !ok {
				config.Remotes["local"] = lxd.LocalRemote
			}
			config.DefaultRemote = "local"
			lxd.SaveConfig(config)
		}
	}

	// This is quite impolite, but it seems gnuflag needs us to shift our
	// own exename out of the arguments before parsing them. However, this
	// is useful for execIfAlias, which wants to know exactly the command
	// line we received, and in some cases is called before this shift, and
	// in others after. So, let's save the original args.
	origArgs := os.Args
	name := os.Args[1]
	cmd, ok := commands[name]
	if !ok {
		execIfAliases(config, origArgs)
		fmt.Fprintf(os.Stderr, i18n.G("error: unknown command: %s")+"\n", name)
		commands["help"].run(nil, nil)
		os.Exit(1)
	}
	cmd.flags()
	gnuflag.Usage = func() {
		fmt.Fprintf(os.Stderr, i18n.G("Usage: %s")+"\n\n"+i18n.G("Options:")+"\n\n", strings.TrimSpace(cmd.usage()))
		gnuflag.PrintDefaults()
	}

	os.Args = os.Args[1:]
	gnuflag.Parse(true)

	shared.Log, err = logging.GetLogger("", "", *verbose, *debug, nil)
	if err != nil {
		return err
	}

	certf := lxd.ConfigPath("client.crt")
	keyf := lxd.ConfigPath("client.key")

	if !*forceLocal && os.Args[0] != "help" && os.Args[0] != "version" && (!shared.PathExists(certf) || !shared.PathExists(keyf)) {
		fmt.Fprintf(os.Stderr, i18n.G("Generating a client certificate. This may take a minute...")+"\n")

		err = shared.FindOrGenCert(certf, keyf)
		if err != nil {
			return err
		}

		fmt.Fprintf(os.Stderr, i18n.G("If this is your first run, you will need to import images using the 'lxd-images' script.")+"\n")
		fmt.Fprintf(os.Stderr, i18n.G("For example: 'lxd-images import ubuntu --alias ubuntu'.")+"\n")
	}

	err = cmd.run(config, gnuflag.Args())
	if err == errArgs {
//.........这里部分代码省略.........