dsfx/cmd/dsfxnode/main.go

package main

import (
	"context"
	"flag"
	"fmt"
	"log/slog"
	"net"
	"os"

	"koti.casa/numenor-labs/dsfx/pkg/crypto/identity"
	"koti.casa/numenor-labs/dsfx/pkg/logging"
	"koti.casa/numenor-labs/dsfx/pkg/network"
)

var (
	flagHost = flag.String("host", "localhost", "the host to listen on")
	flagPort = flag.Int("port", 8000, "the port to listen on")
	flagKey  = flag.String("key", "", "the path to the key file")
)

func main() {
	ctx := context.Background()

	// ---------------------------------------------------------------------------
	// Logger

	opts := &slog.HandlerOptions{
		AddSource: false,
		Level:     slog.LevelDebug,
	}
	logger := slog.New(slog.NewTextHandler(os.Stdout, opts))

	// Everything in the application will attempt to use the logger in stored in
	// the context, but we also set the default with slog as a fallback. In cases
	// where the context is not available, or the context is not a child of the
	// context with the logger, the default logger will be used.
	slog.SetDefault(logger)
	ctx = logging.WithContext(ctx, logger)

	// ---------------------------------------------------------------------------
	// Flags

	flag.Parse()

	if *flagKey == "" {
		slog.ErrorContext(ctx, "master key path is required")
		os.Exit(1)
	}

	masterKey, err := identity.LoadSigningKeyFromFile(*flagKey)
	if err != nil {
		logger.ErrorContext(ctx, "failed to load master key", slog.Any("error", err))
		os.Exit(1)
	}

	tcpAddrRaw := net.JoinHostPort(*flagHost, fmt.Sprint(*flagPort))
	tcpAddr, err := net.ResolveTCPAddr("tcp", tcpAddrRaw)
	if err != nil {
		slog.ErrorContext(ctx, "invalid host or port")
		os.Exit(1)
	}
	addr := network.FromTCPAddr(tcpAddr, identity.ToPublicKey(masterKey))

	// ---------------------------------------------------------------------------
	// Listener

	listener, err := network.Listen(ctx, masterKey, addr)
	if err != nil {
		logger.ErrorContext(ctx, "listener error", slog.Any("error", err))
		os.Exit(1)
	}

	logger.InfoContext(ctx, "listener created", slog.String("address", listener.Addr().String()))

	for {
		conn, err := listener.Accept()
		if err != nil {
			logger.ErrorContext(ctx, "accept failure", slog.Any("error", err))
			continue
		}

		go handleConnection(ctx, conn)
	}
}

func handleConnection(ctx context.Context, conn net.Conn) error {
	defer conn.Close()

	logger := logging.FromContext(ctx)

	msg := make([]byte, 1024)
	n, err := conn.Read(msg)
	if err != nil {
		logger.ErrorContext(ctx, "failed to read from connection", slog.Any("error", err))
		return err
	}

	logger.InfoContext(ctx, "received msg", slog.Int("bytes", n))

	return nil
}