[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

management/cmd/management_test.go

@@ -0,0 +1,59 @@
+package cmd
+
+import (
+	"context"
+	"os"
+	"testing"
+)
+
+const (
+	exampleConfig = `{
+	  "Relay": {
+		"Addresses": [
+		  "rel://192.168.100.1:8085",
+		  "rel://192.168.100.1:8086"
+		],
+		"CredentialsTTL": "12h0m0s",
+		"Secret": "8f7e9d6c5b4a3f2e1d0c9b8a7f6e5d4c3b2a1f0e9d8c7b6a5f4e3d2c1b0a9f8"
+	  },
+	  "HttpConfig": {
+		"AuthAudience": "https://stageapp/",
+		"AuthIssuer": "https://something.eu.auth0.com/",
+		"OIDCConfigEndpoint": "https://something.eu.auth0.com/.well-known/openid-configuration"
+	  }
+	}`
+)
+
+func Test_loadMgmtConfig(t *testing.T) {
+	tmpFile, err := createConfig()
+	if err != nil {
+		t.Fatalf("failed to create config: %s", err)
+	}
+
+	cfg, err := loadMgmtConfig(context.Background(), tmpFile)
+	if err != nil {
+		t.Fatalf("failed to load management config: %s", err)
+	}
+	if cfg.Relay == nil {
+		t.Fatalf("config is nil")
+	}
+	if len(cfg.Relay.Addresses) == 0 {
+		t.Fatalf("relay address is empty")
+	}
+}
+
+func createConfig() (string, error) {
+	tmpfile, err := os.CreateTemp("", "config.json")
+	if err != nil {
+		return "", err
+	}
+	_, err = tmpfile.Write([]byte(exampleConfig))
+	if err != nil {
+		return "", err
+	}
+
+	if err := tmpfile.Close(); err != nil {
+		return "", err
+	}
+	return tmpfile.Name(), nil
+}