server export command fixes

* server export command moved to dedicated package
* added success message to the output
* added support for exporting config file to json format

command/server/config.go → command/server/config/config.go

@@ -1,4 +1,4 @@
-package server
+package config
 
 import (
 	"encoding/json"
@@ -15,7 +15,7 @@ import (
 // Config defines the server configuration params
 type Config struct {
 	GenesisPath       string     `json:"chain_config" yaml:"chain_config"`
-	SecretsConfigPath string     `json:"secrets_config" yaml:"secrets_config,omitempty"`
+	SecretsConfigPath string     `json:"secrets_config" yaml:"secrets_config"`
 	DataDir           string     `json:"data_dir" yaml:"data_dir"`
 	BlockGasTarget    string     `json:"block_gas_target" yaml:"block_gas_target"`
 	GRPCAddr          string     `json:"grpc_addr" yaml:"grpc_addr"`
@@ -95,11 +95,11 @@ func DefaultConfig() *Config {
 	}
 }
 
-// readConfigFile reads the config file from the specified path, builds a Config object
+// ReadConfigFile reads the config file from the specified path, builds a Config object
 // and returns it.
 //
 //Supported file types: .json, .hcl, .yaml, .yml
-func readConfigFile(path string) (*Config, error) {
+func ReadConfigFile(path string) (*Config, error) {
 	data, err := ioutil.ReadFile(path)
 	if err != nil {
 		return nil, err

command/server/export/export.go

@@ -0,0 +1,81 @@
+package export
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"github.com/0xPolygon/polygon-edge/command"
+	"github.com/0xPolygon/polygon-edge/command/server/config"
+	"github.com/spf13/cobra"
+	"gopkg.in/yaml.v3"
+	"os"
+)
+
+func GetCommand() *cobra.Command {
+	configCmd := &cobra.Command{
+		Use:   "export",
+		Short: "export default-config.yaml file with default parameters that can be used to run the server",
+		Run:   runGenerateConfigCommand,
+	}
+
+	setFlags(configCmd)
+
+	return configCmd
+}
+
+func setFlags(cmd *cobra.Command) {
+	cmd.Flags().StringVar(
+		&paramFlagValues.FileType,
+		fileTypeFlag,
+		"yaml",
+		"file type of exported config file (yaml or json)",
+	)
+}
+
+func runGenerateConfigCommand(cmd *cobra.Command, _ []string) {
+	outputter := command.InitializeOutputter(cmd)
+	defer outputter.WriteOutput()
+
+	if err := generateConfig(*config.DefaultConfig()); err != nil {
+		outputter.SetError(err)
+
+		return
+	}
+
+	outputter.SetCommandResult(&cmdResult{
+		CommandOutput: "Configuration file successfully exported",
+	})
+}
+
+func generateConfig(config config.Config) error {
+	config.Network.MaxPeers = -1
+	config.Network.MaxInboundPeers = -1
+	config.Network.MaxOutboundPeers = -1
+
+	var (
+		data []byte
+		err  error
+	)
+
+	switch paramFlagValues.FileType {
+	case "yaml", "yml":
+		data, err = yaml.Marshal(config)
+	case "json":
+		data, err = json.MarshalIndent(config, "", "    ")
+	default:
+		return errors.New("invalid file type, only yaml and json are supported")
+	}
+
+	if err != nil {
+		return fmt.Errorf("could not marshal config struct, %w", err)
+	}
+
+	if err := os.WriteFile(
+		fmt.Sprintf("default-config.%s", paramFlagValues.FileType),
+		data,
+		os.ModePerm); err != nil {
+		return errors.New("could not create and write config file")
+	}
+
+	return nil
+}

command/server/export/params.go

@@ -0,0 +1,13 @@
+package export
+
+const (
+	fileTypeFlag = "type"
+)
+
+type exportParams struct {
+	FileType string
+}
+
+var (
+	paramFlagValues = &exportParams{}
+)

command/server/export/result.go

@@ -0,0 +1,16 @@
+package export
+
+import "bytes"
+
+type cmdResult struct {
+	CommandOutput string `json:"export_result"`
+}
+
+func (c *cmdResult) GetOutput() string {
+	var buffer bytes.Buffer
+
+	buffer.WriteString("\n[EXPORT SUCCESS]\n")
+	buffer.WriteString(c.CommandOutput + "\n")
+
+	return buffer.String()
+}

command/server/init.go

@@ -2,6 +2,7 @@ package server
 
 import (
 	"fmt"
+	"github.com/0xPolygon/polygon-edge/command/server/config"
 	"math"
 	"net"
 
@@ -18,7 +19,7 @@ import (
 func (p *serverParams) initConfigFromFile() error {
 	var parseErr error
 
-	if p.rawConfig, parseErr = readConfigFile(p.configPath); parseErr != nil {
+	if p.rawConfig, parseErr = config.ReadConfigFile(p.configPath); parseErr != nil {
 		return parseErr
 	}
 

command/server/params.go

@@ -2,6 +2,7 @@ package server
 
 import (
 	"errors"
+	"github.com/0xPolygon/polygon-edge/command/server/config"
 	"net"
 
 	"github.com/0xPolygon/polygon-edge/chain"
@@ -42,10 +43,10 @@ const (
 
 var (
 	params = &serverParams{
-		rawConfig: &Config{
-			Telemetry: &Telemetry{},
-			Network:   &Network{},
-			TxPool:    &TxPool{},
+		rawConfig: &config.Config{
+			Telemetry: &config.Telemetry{},
+			Network:   &config.Network{},
+			TxPool:    &config.TxPool{},
 		},
 	}
 )
@@ -56,7 +57,7 @@ var (
 )
 
 type serverParams struct {
-	rawConfig  *Config
+	rawConfig  *config.Config
 	configPath string
 
 	libp2pAddress     *net.TCPAddr

command/server/server.go

@@ -3,6 +3,8 @@ package server
 import (
 	"fmt"
 	"github.com/0xPolygon/polygon-edge/command"
+	"github.com/0xPolygon/polygon-edge/command/server/config"
+	"github.com/0xPolygon/polygon-edge/command/server/export"
 	"github.com/spf13/cobra"
 
 	"github.com/0xPolygon/polygon-edge/command/helper"
@@ -21,15 +23,21 @@ func GetCommand() *cobra.Command {
 	helper.RegisterLegacyGRPCAddressFlag(serverCmd)
 	helper.RegisterJSONRPCFlag(serverCmd)
 
-	// register subcommand used to generate config file on the fly
-	serverCmd.AddCommand(getGenerateConfigCmd())
+	registerSubcommands(serverCmd)
 	setFlags(serverCmd)
 
 	return serverCmd
 }
 
+func registerSubcommands(baseCmd *cobra.Command) {
+	baseCmd.AddCommand(
+		// server export
+		export.GetCommand(),
+	)
+}
+
 func setFlags(cmd *cobra.Command) {
-	defaultConfig := DefaultConfig()
+	defaultConfig := config.DefaultConfig()
 
 	cmd.Flags().StringVar(
 		&params.rawConfig.LogLevel,