unifi-shutd/main.go

package main

import (
	"fmt"
	"log"
	"os"
	"os/exec"
	"strconv"
	"time"

	"github.com/rwinkhart/go-boilerplate/other"
	nut "github.com/rwinkhart/uni-nut"
)

func main() {
	if len(os.Args) != 5 {
		printUsageInfo()
	}
	intervalInt, err := strconv.Atoi(os.Args[3])
	if err != nil {
		other.PrintError("Failed to parse scan interval as integer: "+err.Error(), 2)
	}
	intervalDur := time.Duration(intervalInt) * time.Second
	shutdownMultiplier, err := strconv.Atoi(os.Args[4])
	if err != nil {
		other.PrintError("Failed to parse bad scan limit as integer: "+err.Error(), 3)
	}
	client, err := nut.Dial(os.Args[1])
	if err != nil {
		other.PrintError("Failed to dial NUT server ("+os.Args[1]+"): "+err.Error(), 4)
	}
	log.Println("Starting NUT monitoring loop...")
	cmd := exec.Command("/sbin/poweroff")
	var value string
	var badCycles int
	for {
		time.Sleep(intervalDur)
		value, err = client.GetVar(os.Args[2], "ups.status")
		if err != nil {
			other.PrintError("Failed to get status from \""+os.Args[2]+"\": "+err.Error(), 5)
		}

		switch value {
		case "OB DISCHRG":
			badCycles++
			log.Printf("BAD cycle: %d", badCycles)
		default:
			badCycles = 0
		}
		if badCycles >= shutdownMultiplier {
			log.Println("Bad scan limit reached; initiating shutdown...")
			err := cmd.Run()
			if err != nil {
				other.PrintError("Failed to execute shutdown command: "+err.Error(), 6)
			}
		}
	}
}

func printUsageInfo() {
	fmt.Print("\nUsage: unifi-shutd <host (ip:port)> <ups id> <scan interval (seconds)> <bad scan limit (int)>\n\n")
	os.Exit(0)
}