[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

client/internal/wgproxy/proxy_userspace.go

@@ -3,6 +3,7 @@ package wgproxy
 import (
 	"context"
 	"fmt"
+	"io"
 	"net"
 
 	log "github.com/sirupsen/logrus"
@@ -64,7 +65,6 @@ func (p *WGUserSpaceProxy) Free() error {
 // proxyToRemote proxies everything from Wireguard to the RemoteKey peer
 // blocks
 func (p *WGUserSpaceProxy) proxyToRemote() {
-
 	buf := make([]byte, 1500)
 	for {
 		select {
@@ -73,11 +73,17 @@ func (p *WGUserSpaceProxy) proxyToRemote() {
 		default:
 			n, err := p.localConn.Read(buf)
 			if err != nil {
+				log.Debugf("failed to read from wg interface conn: %s", err)
 				continue
 			}
 
 			_, err = p.remoteConn.Write(buf[:n])
 			if err != nil {
+				if err == io.EOF {
+					p.cancel()
+				} else {
+					log.Debugf("failed to write to remote conn: %s", err)
+				}
 				continue
 			}
 		}
@@ -96,11 +102,17 @@ func (p *WGUserSpaceProxy) proxyToLocal() {
 		default:
 			n, err := p.remoteConn.Read(buf)
 			if err != nil {
+				if err == io.EOF {
+					p.cancel()
+					return
+				}
+				log.Errorf("failed to read from remote conn: %s", err)
 				continue
 			}
 
 			_, err = p.localConn.Write(buf[:n])
 			if err != nil {
+				log.Debugf("failed to write to wg interface conn: %s", err)
 				continue
 			}
 		}