circolog/cmd/circologctl/main.go

package main

import (
	"flag"
	"fmt"
	"io"
	"os"
)

var globalOpts struct {
	ctlSock string
	verbose bool
}

type commandFunc func([]string) error

var cmdMap map[string]commandFunc

func init() {
	cmdMap = map[string]commandFunc{
		// TODO: implement set and get of config at runtime
		//"set":     setCmd,
		//"get":     getCmd,
		"pause":   pauseCmd,
		"reload":  reloadCmd,
		"restart": restartCmd,
		"help":    helpCmd,
	}
}

//func setCmd(ctlSock string, args []string) error {}

//func getCmd(ctlSock string, args []string) error {}

func pauseCmd(args []string) error {
	return nil
}

func reloadCmd(args []string) error {
	return nil
}

func restartCmd(args []string) error {
	return nil
}

func helpCmd(args []string) error {
	usage(os.Stdout)
	os.Exit(0)
	return nil
}

func usage(w io.Writer) {
	fmt.Fprintf(w, "USAGE: %s [globalOpts] [SUBCOMMAND] [opts]\n", os.Args[0])
	fmt.Fprintf(w, "\nSUBCOMMANDS:\n\n")
	for command := range cmdMap {
		fmt.Fprintf(w, "\t%s\n", command)
	}
}

func parseAndRun(args []string) {
	cmdName := args[0]
	cmdToRun, ok := cmdMap[cmdName]
	if !ok {
		fmt.Fprintf(os.Stderr, "Unknown subcommand: %s\n", cmdName)
		usage(os.Stderr)
		os.Exit(2)
	}
	err := cmdToRun(args)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error:\n%s\n", err)
		os.Exit(1)
	}
}

func main() {
	flag.StringVar(&globalOpts.ctlSock, "ctl-socket", "/tmp/circologd-ctl.sock",
		"Path to a unix domain socket for the control server; leave empty to disable")
	flag.BoolVar(&globalOpts.verbose, "verbose", false, "Print more output")
	flag.Parse()
	args := flag.Args()
	if globalOpts.verbose {
		fmt.Fprintf(os.Stdout, "Args: %v", args)
	}
	if len(args) == 0 {
		usage(os.Stderr)
		os.Exit(-1)
	}
	parseAndRun(args)
}