go-tunnel/cmd/client/main.go

package main

import (
	"context"
	"flag"
	"fmt"
	"math/rand"
	"time"

	"cdr.dev/slog"
	"forge.cadoles.com/wpetit/go-tunnel"
	"gitlab.com/wpetit/goweb/logger"
)

const salt = "go-tunnel"

func main() {
	var (
		clientID   = fmt.Sprintf("client-%d", time.Now().Unix())
		serverAddr = "127.0.0.1:36543"
		sharedKey  = "go-tunnel"
	)

	flag.StringVar(&sharedKey, "shared-key", sharedKey, "shared key")
	flag.StringVar(&clientID, "id", clientID, "Client ID")
	flag.StringVar(&serverAddr, "server-addr", serverAddr, "server address")
	flag.Parse()

	ctx := context.Background()
	ctx = logger.With(ctx, logger.F("clientID", clientID))

	logger.SetLevel(slog.LevelDebug)

	client := tunnel.NewClient(
		tunnel.WithClientServerAddress(serverAddr),
		tunnel.WithClientCredentials(clientID),
	)
	defer client.Close()

	initialBackoff := time.Second * 2
	backoff := initialBackoff

	sleep := func() {
		backoff = backoff*2 + (time.Duration(rand.Intn(int(initialBackoff))))

		logger.Info(ctx, "sleeping", logger.F("duration", backoff))
		time.Sleep(backoff)
	}

	for {
		logger.Info(ctx, "connecting")

		if err := client.Connect(ctx); err != nil {
			logger.Error(ctx, "could not connect", logger.E(err))
			sleep()

			continue
		}

		logger.Info(ctx, "waiting for instructions")

		if err := client.Listen(ctx); err != nil {
			logger.Error(ctx, "error while listening", logger.E(err))
		}

		logger.Info(ctx, "connection lost")
		sleep()
	}
}