Merge pull request 'fixed address resolution' (#617) from tron-616 into main

Reviewed-on: #617

api/gateway/tron/internal/service/gateway/tronclient/client.go

@@ -72,8 +72,36 @@ func NewClient(grpcURL string, timeout time.Duration, authToken string, forceIPv
 }
 
 func grpcForceIPv4Dialer(ctx context.Context, address string) (net.Conn, error) {
+	host, port, err := net.SplitHostPort(address)
+	if err != nil {
+		return nil, err
+	}
+
+	ips, err := net.DefaultResolver.LookupIP(ctx, "ip4", host)
+	if err != nil {
+		return nil, err
+	}
+	if len(ips) == 0 {
+		return nil, merrors.Internal(fmt.Sprintf("no IPv4 address found for %s", host))
+	}
+
 	var dialer net.Dialer
-	return dialer.DialContext(ctx, "tcp4", address)
+	var lastErr error
+	for _, ip := range ips {
+		target := net.JoinHostPort(ip.String(), port)
+		conn, err := dialer.DialContext(ctx, "tcp4", target)
+		if err == nil {
+			return conn, nil
+		}
+		lastErr = err
+		if ctx.Err() != nil {
+			break
+		}
+	}
+	if lastErr != nil {
+		return nil, merrors.Internal(fmt.Sprintf("failed to dial any IPv4 address for %s: %v", host, lastErr))
+	}
+	return nil, merrors.Internal(fmt.Sprintf("failed to dial IPv4 address for %s", host))
 }
 
 func normalizeGRPCAddress(grpcURL string) (string, bool, error) {