asynq/tools/asynqmon/cmd/root.go

package cmd

import (
	"fmt"
	"github.com/spf13/cobra"
	"os"

	homedir "github.com/mitchellh/go-homedir"
	"github.com/spf13/viper"
)

var cfgFile string

// Flags
var uri string
var db int

// rootCmd represents the base command when called without any subcommands
var rootCmd = &cobra.Command{
	Use:   "asynqmon",
	Short: "A monitoring tool for asynq queues",
	Long: `TODO(hibiken): A longer description that spans multiple lines and likely contains
examples and usage of using your application. For example:

Cobra is a CLI library for Go that empowers applications.
This application is a tool to generate the needed files
to quickly create a Cobra application.`,
	// Uncomment the following line if your bare application
	// has an action associated with it:
	//	Run: func(cmd *cobra.Command, args []string) { },
}

// Execute adds all child commands to the root command and sets flags appropriately.
// This is called by main.main(). It only needs to happen once to the rootCmd.
func Execute() {
	if err := rootCmd.Execute(); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

func init() {
	cobra.OnInitialize(initConfig)

	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.asynqmon.yaml)")
	rootCmd.PersistentFlags().StringVarP(&uri, "uri", "u", "127.0.0.1:6379", "Redis server URI")
	rootCmd.PersistentFlags().IntVarP(&db, "db", "n", 0, "Redis database number (default is 0)")
}

// initConfig reads in config file and ENV variables if set.
func initConfig() {
	if cfgFile != "" {
		// Use config file from the flag.
		viper.SetConfigFile(cfgFile)
	} else {
		// Find home directory.
		home, err := homedir.Dir()
		if err != nil {
			fmt.Println(err)
			os.Exit(1)
		}

		// Search config in home directory with name ".asynqmon" (without extension).
		viper.AddConfigPath(home)
		viper.SetConfigName(".asynqmon")
	}

	viper.AutomaticEnv() // read in environment variables that match

	// If a config file is found, read it in.
	if err := viper.ReadInConfig(); err == nil {
		fmt.Println("Using config file:", viper.ConfigFileUsed())
	}
}