Update

vendor/gvisor.dev/gvisor/pkg/log/file.go

@@ -0,0 +1,60 @@
+// Copyright 2026 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package log
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// FileOpts contains options for creating a log file.
+type FileOpts interface {
+	// Build constructs the log file path based on the given pattern.
+	Build(logPattern string) string
+}
+
+// DefaultFileOpts is the default implementation of FileOpts which supports no
+// variable substitution.
+type DefaultFileOpts struct{}
+
+// Build implements FileOpts.Build.
+func (f *DefaultFileOpts) Build(logPattern string) string {
+	return logPattern
+}
+
+// OpenFile opens a log file using the specified flags. It uses `opts` to
+// construct the log file path based on the given `logPattern`.
+func OpenFile(logPattern string, flags int, opts FileOpts) (*os.File, error) {
+	if len(logPattern) == 0 {
+		return nil, nil
+	}
+
+	// Replace variables in the log pattern.
+	logPath := opts.Build(logPattern)
+
+	// Create parent directory if it doesn't exist.
+	dir := filepath.Dir(logPath)
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return nil, fmt.Errorf("error creating dir %q: %v", dir, err)
+	}
+
+	// Open file with the specified flags.
+	f, err := os.OpenFile(logPath, flags, 0644)
+	if err != nil {
+		return nil, fmt.Errorf("error opening file %q: %v", logPath, err)
+	}
+	return f, nil
+}