refactor: move federated server logic to its own service (#2914)

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

core/p2p/federated_server.go

@@ -0,0 +1,127 @@
+//go:build p2p
+// +build p2p
+
+package p2p
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+	"time"
+
+	"math/rand/v2"
+
+	"github.com/mudler/edgevpn/pkg/node"
+	"github.com/mudler/edgevpn/pkg/protocol"
+	"github.com/mudler/edgevpn/pkg/types"
+	"github.com/rs/zerolog/log"
+)
+
+func (f *FederatedServer) Start(ctx context.Context) error {
+
+	n, err := NewNode(f.p2ptoken)
+	if err != nil {
+		return fmt.Errorf("creating a new node: %w", err)
+	}
+	err = n.Start(ctx)
+	if err != nil {
+		return fmt.Errorf("creating a new node: %w", err)
+	}
+
+	if err := ServiceDiscoverer(ctx, n, f.p2ptoken, f.service, func(servicesID string, tunnel NodeData) {
+		log.Debug().Msgf("Discovered node: %s", tunnel.ID)
+	}); err != nil {
+		return err
+	}
+
+	return f.proxy(ctx, n)
+}
+
+func (fs *FederatedServer) proxy(ctx context.Context, node *node.Node) error {
+
+	log.Info().Msgf("Allocating service '%s' on: %s", fs.service, fs.listenAddr)
+	// Open local port for listening
+	l, err := net.Listen("tcp", fs.listenAddr)
+	if err != nil {
+		log.Error().Err(err).Msg("Error listening")
+		return err
+	}
+	//	ll.Info("Binding local port on", srcaddr)
+
+	ledger, _ := node.Ledger()
+
+	// Announce ourselves so nodes accepts our connection
+	ledger.Announce(
+		ctx,
+		10*time.Second,
+		func() {
+			// Retrieve current ID for ip in the blockchain
+			//_, found := ledger.GetKey(protocol.UsersLedgerKey, node.Host().ID().String())
+			// If mismatch, update the blockchain
+			//if !found {
+			updatedMap := map[string]interface{}{}
+			updatedMap[node.Host().ID().String()] = &types.User{
+				PeerID:    node.Host().ID().String(),
+				Timestamp: time.Now().String(),
+			}
+			ledger.Add(protocol.UsersLedgerKey, updatedMap)
+			//	}
+		},
+	)
+
+	defer l.Close()
+	for {
+		select {
+		case <-ctx.Done():
+			return errors.New("context canceled")
+		default:
+			log.Debug().Msg("New for connection")
+			// Listen for an incoming connection.
+			conn, err := l.Accept()
+			if err != nil {
+				fmt.Println("Error accepting: ", err.Error())
+				continue
+			}
+
+			// Handle connections in a new goroutine, forwarding to the p2p service
+			go func() {
+				var tunnelAddresses []string
+				for _, v := range GetAvailableNodes(fs.service) {
+					if v.IsOnline() {
+						tunnelAddresses = append(tunnelAddresses, v.TunnelAddress)
+					} else {
+						log.Info().Msgf("Node %s is offline", v.ID)
+					}
+				}
+
+				if len(tunnelAddresses) == 0 {
+					log.Error().Msg("No available nodes yet")
+					return
+				}
+
+				// open a TCP stream to one of the tunnels
+				// chosen randomly
+				// TODO: optimize this and track usage
+				tunnelAddr := tunnelAddresses[rand.IntN(len(tunnelAddresses))]
+
+				tunnelConn, err := net.Dial("tcp", tunnelAddr)
+				if err != nil {
+					log.Error().Err(err).Msg("Error connecting to tunnel")
+					return
+				}
+
+				log.Info().Msgf("Redirecting %s to %s", conn.LocalAddr().String(), tunnelConn.RemoteAddr().String())
+				closer := make(chan struct{}, 2)
+				go copyStream(closer, tunnelConn, conn)
+				go copyStream(closer, conn, tunnelConn)
+				<-closer
+
+				tunnelConn.Close()
+				conn.Close()
+				//	ll.Infof("(service %s) Done handling %s", serviceID, l.Addr().String())
+			}()
+		}
+	}
+
+}