[relay] Feature/relay integration (#2244)

This update adds new relay integration for NetBird clients. The new relay is based on web sockets and listens on a single port.

- Adds new relay implementation with websocket with single port relaying mechanism
- refactor peer connection logic, allowing upgrade and downgrade from/to P2P connection
- peer connections are faster since it connects first to relay and then upgrades to P2P
- maintains compatibility with old clients by not using the new relay
- updates infrastructure scripts with new relay service

relay/testec2/turn_allocator.go

@@ -0,0 +1,83 @@
+//go:build linux || darwin
+
+package main
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/pion/logging"
+	"github.com/pion/turn/v3"
+	log "github.com/sirupsen/logrus"
+)
+
+type TurnConn struct {
+	conn       net.Conn
+	turnClient *turn.Client
+	relayConn  net.PacketConn
+}
+
+func (tc *TurnConn) Address() net.Addr {
+	return tc.relayConn.LocalAddr()
+}
+
+func (tc *TurnConn) Close() {
+	_ = tc.relayConn.Close()
+	tc.turnClient.Close()
+	_ = tc.conn.Close()
+}
+
+func AllocateTurnClient(serverAddr string) *TurnConn {
+	conn, err := net.Dial("tcp", serverAddr)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	turnClient, err := getTurnClient(serverAddr, conn)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	relayConn, err := turnClient.Allocate()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return &TurnConn{
+		conn:       conn,
+		turnClient: turnClient,
+		relayConn:  relayConn,
+	}
+}
+
+func getTurnClient(address string, conn net.Conn) (*turn.Client, error) {
+	// Dial TURN Server
+	addrStr := fmt.Sprintf("%s:%d", address, 443)
+
+	fac := logging.NewDefaultLoggerFactory()
+	//fac.DefaultLogLevel = logging.LogLevelTrace
+
+	// Start a new TURN Client and wrap our net.Conn in a STUNConn
+	// This allows us to simulate datagram based communication over a net.Conn
+	cfg := &turn.ClientConfig{
+		TURNServerAddr: address,
+		Conn:           turn.NewSTUNConn(conn),
+		Username:       "test",
+		Password:       "test",
+		LoggerFactory:  fac,
+	}
+
+	client, err := turn.NewClient(cfg)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create TURN client for server %s: %s", addrStr, err)
+	}
+
+	// Start listening on the conn provided.
+	err = client.Listen()
+	if err != nil {
+		client.Close()
+		return nil, fmt.Errorf("failed to listen on TURN client for server %s: %s", addrStr, err)
+	}
+
+	return client, nil
+}