package main

import (
    "net"
    "os/exec"
    "time"
)

const (
    target        = "192.168.1.50:8080" // IP:porta da controllare
    serviceName   = "mioservizio"       // servizio systemd
    checkInterval = 5 * time.Second
    maxFailures   = 3
    timeout       = 2 * time.Second
)

func checkTCP(addr string, timeout time.Duration) bool {
    conn, err := net.DialTimeout("tcp", addr, timeout)
    if err != nil {
        return false
    }
    conn.Close()
    return true
}

func systemctl(action string) {
    cmd := exec.Command("systemctl", action, serviceName)
    cmd.Run()
}

func main() {
    failCount := 0
    serviceDown := false

    for {
        ok := checkTCP(target, timeout)

        if ok {
            failCount = 0
            if serviceDown {
                systemctl("start")
                serviceDown = false
            }
        } else {
            failCount++
            if failCount >= maxFailures && !serviceDown {
                systemctl("stop")
                serviceDown = true
            }
        }

        time.Sleep(checkInterval)
    }
}