feature: add 'config default' command to print the default configurat…

…ion of components

Signed-off-by: SataQiu <[email protected]>

cmd/dfdaemon/app/root.go

@@ -106,7 +106,10 @@ func init() {
 	rf.StringSlice("node", nil, "specify the addresses(host:port) of supernodes that will be passed to dfget.")
 
 	exitOnError(bindRootFlags(viper.GetViper()), "bind root command flags")
+
+	// add sub commands
 	rootCmd.AddCommand(cmd.NewGenDocCommand("dfdaemon"))
+	rootCmd.AddCommand(cmd.NewConfigCommand("dfdaemon", getDefaultConfig))
 }
 
 // bindRootFlags binds flags on rootCmd to the given viper instance.
@@ -159,6 +162,11 @@ func Execute() {
 	}
 }
 
+// getDefaultConfig returns the default configuration of dfdaemon
+func getDefaultConfig() (interface{}, error) {
+	return getConfigFromViper(rootCmd, viper.GetViper())
+}
+
 // getConfigFromViper returns dfdaemon config from the given viper instance
 func getConfigFromViper(cmd *cobra.Command, v *viper.Viper) (*config.Properties, error) {
 	// override supernodes in config file if --node is specified in cli.

cmd/supernode/app/root.go

@@ -122,7 +122,10 @@ var rootCmd = &cobra.Command{
 
 func init() {
 	setupFlags(rootCmd)
+
+	// add sub commands
 	rootCmd.AddCommand(cmd.NewGenDocCommand("supernode"))
+	rootCmd.AddCommand(cmd.NewConfigCommand("supernode", getDefaultConfig))
 }
 
 // setupFlags setups flags for command line.
@@ -297,6 +300,11 @@ func readConfigFile(v *viper.Viper, cmd *cobra.Command) error {
 	return nil
 }
 
+// getDefaultConfig returns the default configuration of supernode
+func getDefaultConfig() (interface{}, error) {
+	return getConfigFromViper(viper.GetViper())
+}
+
 // getConfigFromViper returns supernode config from the given viper instance
 func getConfigFromViper(v *viper.Viper) (*config.Config, error) {
 	cfg := config.NewConfig()

pkg/cmd/config.go

@@ -0,0 +1,67 @@
+/*
+ * Copyright The Dragonfly Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cmd
+
+import (
+	"fmt"
+
+	"github.com/dragonflyoss/Dragonfly/pkg/printer"
+
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+	"gopkg.in/yaml.v2"
+)
+
+// NewConfigCommand returns cobra.Command for "<component> config" command
+func NewConfigCommand(componentName string, defaultComponentConfigFunc func() (interface{}, error)) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "config",
+		Short: fmt.Sprintf("Manage the configurations of %s", componentName),
+		Args:  cobra.NoArgs,
+	}
+
+	cmd.AddCommand(newConfigPrintDefaultCommand(componentName, defaultComponentConfigFunc))
+	return cmd
+}
+
+// newConfigPrintDefaultCommand returns cobra.Command for "<component> config default" command
+func newConfigPrintDefaultCommand(componentName string, defaultComponentConfigFunc func() (interface{}, error)) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:           "default",
+		Short:         fmt.Sprintf("Print the default configurations of %s in yaml format", componentName),
+		Args:          cobra.NoArgs,
+		SilenceErrors: true,
+		SilenceUsage:  true,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runConfigPrintDefault(defaultComponentConfigFunc)
+		},
+	}
+	return cmd
+}
+
+func runConfigPrintDefault(defaultComponentConfigFunc func() (interface{}, error)) error {
+	cfg, err := defaultComponentConfigFunc()
+	if err != nil {
+		return errors.Wrap(err, "failed to get component default configurations")
+	}
+	d, err := yaml.Marshal(cfg)
+	if err != nil {
+		return errors.Wrap(err, "failed to marshal component default configurations")
+	}
+	printer.Print(string(d))
+	return nil
+}

pkg/printer/printer.go

@@ -34,6 +34,13 @@ type StdPrinter struct {
 	Out io.Writer
 }
 
+// Println outputs info to console directly.
+func (sp *StdPrinter) Print(msg string) {
+	if sp.Out != nil {
+		fmt.Fprint(sp.Out, msg)
+	}
+}
+
 // Println outputs info to console directly.
 func (sp *StdPrinter) Println(msg string) {
 	if sp.Out != nil {
@@ -48,6 +55,13 @@ func (sp *StdPrinter) Printf(format string, a ...interface{}) {
 	}
 }
 
+// Print outputs info to console directly.
+func Print(msg string) {
+	if Printer.Out != nil {
+		fmt.Fprint(Printer.Out, msg)
+	}
+}
+
 // Println outputs info to console directly.
 func Println(msg string) {
 	if Printer.Out != nil {