Wireguard reconnection For NetworkManager When connection go wrong

network-manager-wireguard-reconnection.go

package main

import (
	"bytes"
	"flag"
	"net/http"
	"os/exec"
	"strings"
	"time"

	"github.com/rs/zerolog"
	"github.com/rs/zerolog/log"
)

const MAX_FAILED = 5
const DELAY_DEV_CHECK_TIME = 3
const DELAY_TIME = 2
const DEV_NETWORK = "tun1"

func checkOnline(httpClient *http.Client, channel chan bool) {
	response, err := httpClient.Get("http://clients3.google.com/generate_204")
	log.Debug().Msg("Network requested")
	if err != nil {
		log.Error().Msg("Network error")
		channel <- false
		return
	}
	if response.StatusCode == 204 {
		log.Debug().Msg("Network online")
		channel <- true
	} else {
		log.Error().Msg("Not return 204 something went wrong !!!")
		channel <- false
	}

}

func isVirtualNetworkActive() bool {
	_, output := executeCommand("nmcli", "connection", "show", "--active")

	return strings.Contains(output, DEV_NETWORK)
}

func executeCommand(executable string, args ...string) (success bool, output string) {
	var stdOut, stdErr bytes.Buffer

	cmd := exec.Command(executable, args...)
	cmd.Stdout = &stdOut
	cmd.Stderr = &stdErr
	err := cmd.Run()
	if err != nil {
		return false, stdErr.String()
	}

	return true, stdOut.String()
}

func resetNetwork() {
	_, deactiveOutput := executeCommand("nmcli", "connection", "down", DEV_NETWORK)
	log.Debug().Msg(deactiveOutput)
	_, activateOutput := executeCommand("nmcli", "connection", "up", DEV_NETWORK)
	log.Debug().Msg(activateOutput)
}

func main() {
	debug := flag.Bool("debug", false, "sets log level to debug")
	flag.Parse()
	zerolog.SetGlobalLevel(zerolog.InfoLevel)
	if *debug {
		zerolog.SetGlobalLevel(zerolog.DebugLevel)
	}

	connectFailedCount := 0
	checkConnectionChannel := make(chan bool)
	var httpClient = &http.Client{
		Timeout: time.Second * 1,
	}

	for {
		if !isVirtualNetworkActive() {
			log.Debug().Msgf("Taget network: %s not actived", DEV_NETWORK)
			time.Sleep(time.Second * DELAY_DEV_CHECK_TIME)
			continue
		}

		go checkOnline(httpClient, checkConnectionChannel)
		isCheckOnlineResult := <-checkConnectionChannel
		if isCheckOnlineResult {
			connectFailedCount = 0
		} else {
			connectFailedCount += 1
		}

		if connectFailedCount >= MAX_FAILED {
			log.Error().Msg("Connection down count reached reset network !")
			resetNetwork()
			connectFailedCount = 0
		}
		time.Sleep(time.Second * DELAY_TIME)
	}
}