Add default-config command.

Signed-off-by: Lantao Liu <lantaol@google.com>

cmd/cri-containerd/cri_containerd.go

@@ -52,6 +52,16 @@ func init() {
 	cmd.PersistentFlags().AddGoFlagSet(flag.CommandLine)
 }
 
+func defaultConfigCommand() *cobra.Command {
+	return &cobra.Command{
+		Use:   "default-config",
+		Short: "Print default toml config of cri-containerd and quit.",
+		Run: func(cmd *cobra.Command, args []string) {
+			options.PrintDefaultTomlConfig()
+		},
+	}
+}
+
 func main() {
 	if reexec.Init() {
 		return
@@ -59,6 +69,7 @@ func main() {
 	o := options.NewCRIContainerdOptions()
 
 	o.AddFlags(cmd.Flags())
+	cmd.AddCommand(defaultConfigCommand())
 
 	cmd.Run = func(cmd *cobra.Command, args []string) {
 		if err := o.InitFlags(cmd.Flags()); err != nil {
@@ -71,11 +82,6 @@ func main() {
 			version.PrintVersion()
 			os.Exit(0)
 		}
-
-		if o.PrintDefaultConfig {
-			o.PrintDefaultTomlConfig()
-			os.Exit(0)
-		}
 		validateConfig(o)
 
 		glog.V(2).Infof("Run cri-containerd grpc server on socket %q", o.SocketPath)

cmd/cri-containerd/options/options.go

@@ -97,8 +97,6 @@ type CRIContainerdOptions struct {
 	ConfigFilePath string `toml:"-"`
 	// PrintVersion indicates to print version information of cri-containerd.
 	PrintVersion bool
-	// PrintDefaultConfig indicates to print default toml config of cri-containerd.
-	PrintDefaultConfig bool
 }
 
 // NewCRIContainerdOptions returns a reference to CRIContainerdOptions
@@ -108,48 +106,47 @@ func NewCRIContainerdOptions() *CRIContainerdOptions {
 
 // AddFlags adds cri-containerd command line options to pflag.
 func (c *CRIContainerdOptions) AddFlags(fs *pflag.FlagSet) {
+	defaults := defaultConfig()
 	fs.StringVar(&c.ConfigFilePath, configFilePathArgName,
 		defaultConfigFilePath, "Path to the config file.")
 	fs.StringVar(&c.SocketPath, "socket-path",
-		"/var/run/cri-containerd.sock", "Path to the socket which cri-containerd serves on.")
+		defaults.SocketPath, "Path to the socket which cri-containerd serves on.")
 	fs.StringVar(&c.RootDir, "root-dir",
-		"/var/lib/cri-containerd", "Root directory path for cri-containerd managed files (metadata checkpoint etc).")
+		defaults.RootDir, "Root directory path for cri-containerd managed files (metadata checkpoint etc).")
 	fs.StringVar(&c.ContainerdConfig.RootDir, "containerd-root-dir",
-		"/var/lib/containerd", "Root directory path where containerd stores persistent data.")
+		defaults.ContainerdConfig.RootDir, "Root directory path where containerd stores persistent data.")
 	fs.StringVar(&c.ContainerdConfig.Endpoint, "containerd-endpoint",
-		"/run/containerd/containerd.sock", "Path to the containerd endpoint.")
+		defaults.ContainerdConfig.Endpoint, "Path to the containerd endpoint.")
 	fs.StringVar(&c.ContainerdConfig.Snapshotter, "containerd-snapshotter",
-		containerd.DefaultSnapshotter, "The snapshotter used by containerd.")
+		defaults.ContainerdConfig.Snapshotter, "The snapshotter used by containerd.")
 	fs.StringVar(&c.ContainerdConfig.Runtime, "containerd-runtime",
-		"io.containerd.runtime.v1.linux", "The runtime used by containerd.")
+		defaults.ContainerdConfig.Runtime, "The runtime used by containerd.")
 	fs.StringVar(&c.ContainerdConfig.RuntimeEngine, "containerd-runtime-engine",
-		"", "Runtime engine used by containerd. Defaults to containerd's default if not specified.")
+		defaults.ContainerdConfig.RuntimeEngine, "Runtime engine used by containerd. Defaults to containerd's default if not specified.")
 	fs.StringVar(&c.ContainerdConfig.RuntimeRoot, "containerd-runtime-root",
-		"", "The directory used by containerd for runtime state. Defaults to containerd's default if not specified.")
+		defaults.ContainerdConfig.RuntimeRoot, "The directory used by containerd for runtime state. Defaults to containerd's default if not specified.")
 	fs.BoolVar(&c.PrintVersion, "version",
 		false, "Print cri-containerd version information and quit.")
 	fs.StringVar(&c.NetworkPluginBinDir, "network-bin-dir",
-		"/opt/cni/bin", "The directory for putting network binaries.")
+		defaults.NetworkPluginBinDir, "The directory for putting network binaries.")
 	fs.StringVar(&c.NetworkPluginConfDir, "network-conf-dir",
-		"/etc/cni/net.d", "The directory for putting network plugin configuration files.")
+		defaults.NetworkPluginConfDir, "The directory for putting network plugin configuration files.")
 	fs.StringVar(&c.StreamServerAddress, "stream-addr",
-		"", "The ip address streaming server is listening on. The default host interface is used if not specified.")
+		defaults.StreamServerAddress, "The ip address streaming server is listening on. The default host interface is used if not specified.")
 	fs.StringVar(&c.StreamServerPort, "stream-port",
-		"10010", "The port streaming server is listening on.")
+		defaults.StreamServerPort, "The port streaming server is listening on.")
 	fs.StringVar(&c.CgroupPath, "cgroup-path",
-		"", "The cgroup that cri-containerd is part of. Cri-containerd is not placed in a cgroup if none is specified.")
+		defaults.CgroupPath, "The cgroup that cri-containerd is part of. Cri-containerd is not placed in a cgroup if none is specified.")
 	fs.BoolVar(&c.EnableSelinux, "enable-selinux",
-		false, "Enable selinux support. By default not enabled.")
+		defaults.EnableSelinux, "Enable selinux support. By default not enabled.")
 	fs.StringVar(&c.SandboxImage, "sandbox-image",
-		"gcr.io/google_containers/pause:3.0", "The image used by sandbox container.")
+		defaults.SandboxImage, "The image used by sandbox container.")
 	fs.IntVar(&c.StatsCollectPeriod, "stats-collect-period",
-		10, "The period (in seconds) of snapshots stats collection.")
+		defaults.StatsCollectPeriod, "The period (in seconds) of snapshots stats collection.")
 	fs.BoolVar(&c.SystemdCgroup, "systemd-cgroup",
-		false, "Enables systemd cgroup support. By default not enabled.")
+		defaults.SystemdCgroup, "Enables systemd cgroup support. By default not enabled.")
-	fs.BoolVar(&c.PrintDefaultConfig, "default-config",
-		false, "Print default toml config of cri-containerd and quit.")
 	fs.IntVar(&c.OOMScore, "oom-score",
-		-999, "Adjust the cri-containerd's oom score.")
+		defaults.OOMScore, "Adjust the cri-containerd's oom score.")
 }
 
 // InitFlags load configurations from config file, and then overwrite with flags.
@@ -178,13 +175,37 @@ func (c *CRIContainerdOptions) InitFlags(fs *pflag.FlagSet) error {
 }
 
 // PrintDefaultTomlConfig print default toml config of cri-containerd.
-func (c *CRIContainerdOptions) PrintDefaultTomlConfig() {
+func PrintDefaultTomlConfig() {
-	fs := pflag.NewFlagSet("default-config", pflag.ExitOnError)
+	if err := toml.NewEncoder(os.Stdout).Encode(defaultConfig()); err != nil {
-
-	c.AddFlags(fs)
-
-	if err := toml.NewEncoder(os.Stdout).Encode(c.Config); err != nil {
 		fmt.Println(err)
 		return
 	}
 }
+
+// defaultConfig returns default configurations of cri-containerd.
+func defaultConfig() Config {
+	return Config{
+		ContainerdConfig: ContainerdConfig{
+			RootDir:       "/var/lib/containerd",
+			Snapshotter:   containerd.DefaultSnapshotter,
+			Endpoint:      "/run/containerd/containerd.sock",
+			Runtime:       "io.containerd.runtime.v1.linux",
+			RuntimeEngine: "",
+			RuntimeRoot:   "",
+		},
+		CniConfig: CniConfig{
+			NetworkPluginBinDir:  "/opt/cni/bin",
+			NetworkPluginConfDir: "/etc/cni/net.d",
+		},
+		SocketPath:          "/var/run/cri-containerd.sock",
+		RootDir:             "/var/lib/cri-containerd",
+		StreamServerAddress: "",
+		StreamServerPort:    "10010",
+		CgroupPath:          "",
+		EnableSelinux:       false,
+		SandboxImage:        "gcr.io/google_containers/pause:3.0",
+		StatsCollectPeriod:  10,
+		SystemdCgroup:       false,
+		OOMScore:            -999,
+	}
+}