policy-reader/modules/root.go

package modules

import (
	"context"
	"os"
	"runtime"
	"strings"

	"git.frostfs.info/dkirillov/policy-reader/internal/version"
	"git.frostfs.info/dkirillov/policy-reader/modules/contract"
	"github.com/spf13/cobra"
	"github.com/spf13/viper"
)

// rootCmd represents the base command when called without any subcommands.
var rootCmd = &cobra.Command{
	Use:           "policy-reader",
	Version:       version.Version,
	Short:         "FrostFS policy contract reader",
	Long:          "Helps reading policy information from contact in FrostFS network",
	Example:       "policy-reader --version",
	SilenceErrors: true,
	SilenceUsage:  true,
	PersistentPreRunE: func(cmd *cobra.Command, _ []string) error {
		viper.AutomaticEnv()
		viper.SetEnvPrefix("POLICY_READER")
		viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
		viper.AllowEmptyEnv(true)
		viper.SetConfigType("yaml")

		if err := viper.BindPFlags(cmd.Flags()); err != nil {
			return err
		}

		if viper.IsSet(configFlag) {
			return readConfig(viper.GetViper(), viper.GetString(configFlag))
		}

		return nil
	},
	RunE: func(cmd *cobra.Command, _ []string) error {
		return cmd.Help()
	},
}

func Execute(ctx context.Context) (*cobra.Command, error) {
	return rootCmd.ExecuteContextC(ctx)
}

const configFlag = "config"

func init() {
	cobra.EnableTraverseRunHooks = true
	rootCmd.PersistentFlags().StringP(configFlag, "c", "", "Path to config file")

	cobra.AddTemplateFunc("runtimeVersion", runtime.Version)
	rootCmd.SetVersionTemplate(`Frostfs policy reader
{{printf "Version: %s" .Version }}
GoVersion: {{ runtimeVersion }}
`)

	rootCmd.AddCommand(contract.Cmd)
}

func readConfig(v *viper.Viper, fileName string) error {
	cfgFile, err := os.Open(fileName)
	if err != nil {
		return err
	}

	defer func() {
		if errClose := cfgFile.Close(); errClose != nil {
			panic(errClose)
		}
	}()

	return v.ReadConfig(cfgFile)
}