Implements a new generate-config subcommand that auto-generates examp…

cmd/k3s/main.go

@@ -14,6 +14,7 @@ import (
 	"strings"
 
 	"github.com/k3s-io/k3s/pkg/cli/cmds"
+	"github.com/k3s-io/k3s/pkg/cli/generateconfig"
 	"github.com/k3s-io/k3s/pkg/configfilearg"
 	"github.com/k3s-io/k3s/pkg/data"
 	"github.com/k3s-io/k3s/pkg/datadir"
@@ -91,6 +92,7 @@ func main() {
 			internalCLIAction(version.Program+"-completion", dataDir, os.Args),
 			internalCLIAction(version.Program+"-completion", dataDir, os.Args),
 		),
+		cmds.NewGenerateConfigCommand(generateconfig.Run),
 	}
 
 	if err := app.Run(os.Args); err != nil && !errors.Is(err, context.Canceled) {

main.go

@@ -11,6 +11,7 @@ import (
 	"github.com/k3s-io/k3s/pkg/cli/completion"
 	"github.com/k3s-io/k3s/pkg/cli/crictl"
 	"github.com/k3s-io/k3s/pkg/cli/etcdsnapshot"
+	"github.com/k3s-io/k3s/pkg/cli/generateconfig"
 	"github.com/k3s-io/k3s/pkg/cli/kubectl"
 	"github.com/k3s-io/k3s/pkg/cli/secretsencrypt"
 	"github.com/k3s-io/k3s/pkg/cli/server"
@@ -53,6 +54,7 @@ func main() {
 			completion.Bash,
 			completion.Zsh,
 		),
+		cmds.NewGenerateConfigCommand(generateconfig.Run),
 	}
 
 	if err := app.Run(configfilearg.MustParse(os.Args)); err != nil && !errors.Is(err, context.Canceled) {

pkg/cli/cmds/agent.go

@@ -259,85 +259,87 @@ var (
 	}
 )
 
+var AgentFlags = []cli.Flag{
+	ConfigFlag,
+	DebugFlag,
+	VLevel,
+	VModule,
+	LogFile,
+	AlsoLogToStderr,
+	AgentTokenFlag,
+	&cli.StringFlag{
+		Name:        "token-file",
+		Usage:       "(cluster) Token file to use for authentication",
+		EnvVars:     []string{version.ProgramUpper + "_TOKEN_FILE"},
+		Destination: &AgentConfig.TokenFile,
+	},
+	&cli.StringFlag{
+		Name:        "server",
+		Aliases:     []string{"s"},
+		Usage:       "(cluster) Server to connect to",
+		EnvVars:     []string{version.ProgramUpper + "_URL"},
+		Destination: &AgentConfig.ServerURL,
+	},
+	// Note that this is different from DataDirFlag used elswhere in the CLI,
+	// as this is bound to AgentConfig instead of ServerConfig.
+	&cli.StringFlag{
+		Name:        "data-dir",
+		Aliases:     []string{"d"},
+		Usage:       "(agent/data) Folder to hold state",
+		Destination: &AgentConfig.DataDir,
+		Value:       "/var/lib/rancher/" + version.Program + "",
+		EnvVars:     []string{version.ProgramUpper + "_DATA_DIR"},
+	},
+	NodeNameFlag,
+	WithNodeIDFlag,
+	NodeLabels,
+	NodeTaints,
+	ImageCredProvBinDirFlag,
+	ImageCredProvConfigFlag,
+	SELinuxFlag,
+	LBServerPortFlag,
+	ProtectKernelDefaultsFlag,
+	CRIEndpointFlag,
+	DefaultRuntimeFlag,
+	ImageServiceEndpointFlag,
+	PauseImageFlag,
+	SnapshotterFlag,
+	PrivateRegistryFlag,
+	DisableDefaultRegistryEndpointFlag,
+	NonrootDevicesFlag,
+	AirgapExtraRegistryFlag,
+	NodeIPFlag,
+	BindAddressFlag,
+	NodeExternalIPFlag,
+	NodeInternalDNSFlag,
+	NodeExternalDNSFlag,
+	ResolvConfFlag,
+	FlannelIfaceFlag,
+	FlannelConfFlag,
+	FlannelCniConfFileFlag,
+	ExtraKubeletArgs,
+	ExtraKubeProxyArgs,
+	// Experimental flags
+	EnablePProfFlag,
+	&cli.BoolFlag{
+		Name:        "rootless",
+		Usage:       "(experimental) Run rootless",
+		Destination: &AgentConfig.Rootless,
+	},
+	PreferBundledBin,
+	// Deprecated/hidden below
+	DockerFlag,
+	VPNAuth,
+	VPNAuthFile,
+	DisableAgentLBFlag,
+}
+
 func NewAgentCommand(action func(ctx *cli.Context) error) *cli.Command {
 	return &cli.Command{
 		Name:      "agent",
 		Usage:     "Run node agent",
 		UsageText: appName + " agent [OPTIONS]",
 		Action:    action,
-		Flags: []cli.Flag{
-			ConfigFlag,
-			DebugFlag,
-			VLevel,
-			VModule,
-			LogFile,
-			AlsoLogToStderr,
-			AgentTokenFlag,
-			&cli.StringFlag{
-				Name:        "token-file",
-				Usage:       "(cluster) Token file to use for authentication",
-				EnvVars:     []string{version.ProgramUpper + "_TOKEN_FILE"},
-				Destination: &AgentConfig.TokenFile,
-			},
-			&cli.StringFlag{
-				Name:        "server",
-				Aliases:     []string{"s"},
-				Usage:       "(cluster) Server to connect to",
-				EnvVars:     []string{version.ProgramUpper + "_URL"},
-				Destination: &AgentConfig.ServerURL,
-			},
-			// Note that this is different from DataDirFlag used elswhere in the CLI,
-			// as this is bound to AgentConfig instead of ServerConfig.
-			&cli.StringFlag{
-				Name:        "data-dir",
-				Aliases:     []string{"d"},
-				Usage:       "(agent/data) Folder to hold state",
-				Destination: &AgentConfig.DataDir,
-				Value:       "/var/lib/rancher/" + version.Program + "",
-				EnvVars:     []string{version.ProgramUpper + "_DATA_DIR"},
-			},
-			NodeNameFlag,
-			WithNodeIDFlag,
-			NodeLabels,
-			NodeTaints,
-			ImageCredProvBinDirFlag,
-			ImageCredProvConfigFlag,
-			SELinuxFlag,
-			LBServerPortFlag,
-			ProtectKernelDefaultsFlag,
-			CRIEndpointFlag,
-			DefaultRuntimeFlag,
-			ImageServiceEndpointFlag,
-			PauseImageFlag,
-			SnapshotterFlag,
-			PrivateRegistryFlag,
-			DisableDefaultRegistryEndpointFlag,
-			NonrootDevicesFlag,
-			AirgapExtraRegistryFlag,
-			NodeIPFlag,
-			BindAddressFlag,
-			NodeExternalIPFlag,
-			NodeInternalDNSFlag,
-			NodeExternalDNSFlag,
-			ResolvConfFlag,
-			FlannelIfaceFlag,
-			FlannelConfFlag,
-			FlannelCniConfFileFlag,
-			ExtraKubeletArgs,
-			ExtraKubeProxyArgs,
-			// Experimental flags
-			EnablePProfFlag,
-			&cli.BoolFlag{
-				Name:        "rootless",
-				Usage:       "(experimental) Run rootless",
-				Destination: &AgentConfig.Rootless,
-			},
-			PreferBundledBin,
-			// Deprecated/hidden below
-			DockerFlag,
-			VPNAuth,
-			VPNAuthFile,
-			DisableAgentLBFlag,
-		},
+		Flags:     AgentFlags,
 	}
 }

pkg/cli/cmds/generate_config.go

@@ -0,0 +1,48 @@
+package cmds
+
+import (
+	"github.com/urfave/cli/v2"
+)
+
+const GenerateConfigCommand = "generate-config"
+
+type GenerateConfig struct {
+	Output     string
+	ConfigType string
+	FromConfig string
+}
+
+var (
+	GenerateConfigConfig = GenerateConfig{}
+	GenerateConfigFlags  = []cli.Flag{
+		DebugFlag,
+		&cli.StringFlag{
+			Name:        "output",
+			Aliases:     []string{"o"},
+			Usage:       "Output file path (default: stdout)",
+			Destination: &GenerateConfigConfig.Output,
+		},
+		&cli.StringFlag{
+			Name:        "type",
+			Aliases:     []string{"t"},
+			Usage:       "Config type to generate (server or agent)",
+			Value:       "server",
+			Destination: &GenerateConfigConfig.ConfigType,
+		},
+		&cli.StringFlag{
+			Name:        "from-config",
+			Usage:       "Read existing config file to show current values",
+			Destination: &GenerateConfigConfig.FromConfig,
+		},
+	}
+)
+
+func NewGenerateConfigCommand(action func(*cli.Context) error) *cli.Command {
+	return &cli.Command{
+		Name:            GenerateConfigCommand,
+		Usage:           "Generate an example k3s config file",
+		SkipFlagParsing: false,
+		Action:          action,
+		Flags:           GenerateConfigFlags,
+	}
+}