initial: Syntrex extraction from sentinel-community (615 files)

internal/infrastructure/audit/rotation.go

@@ -0,0 +1,96 @@
+package audit
+
+import (
+	"compress/gzip"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"time"
+)
+
+const (
+	// MaxLogSize is the default rotation threshold (100 MB).
+	MaxLogSize int64 = 100 * 1024 * 1024
+)
+
+// RotationResult describes the outcome of a rotation attempt.
+type RotationResult struct {
+	Rotated      bool   `json:"rotated"`
+	OriginalSize int64  `json:"original_size"`
+	ArchivePath  string `json:"archive_path,omitempty"`
+	ArchiveSize  int64  `json:"archive_size,omitempty"`
+}
+
+// RotateIfNeeded checks the decisions.log size and rotates if it exceeds maxSize.
+// Rotation: rename → gzip compress → create new empty log.
+// Returns rotation result.
+func RotateIfNeeded(rlmDir string, maxSize int64) (RotationResult, error) {
+	if maxSize <= 0 {
+		maxSize = MaxLogSize
+	}
+
+	logPath := filepath.Join(rlmDir, decisionsFileName)
+	info, err := os.Stat(logPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return RotationResult{Rotated: false}, nil
+		}
+		return RotationResult{}, err
+	}
+
+	if info.Size() < maxSize {
+		return RotationResult{Rotated: false, OriginalSize: info.Size()}, nil
+	}
+
+	// Generate archive name with timestamp.
+	ts := time.Now().Format("20060102_150405")
+	archiveName := fmt.Sprintf("decisions_%s.log.gz", ts)
+	archivePath := filepath.Join(rlmDir, archiveName)
+
+	// Compress the log file.
+	if err := compressFile(logPath, archivePath); err != nil {
+		return RotationResult{}, fmt.Errorf("rotation: compress: %w", err)
+	}
+
+	archiveInfo, _ := os.Stat(archivePath)
+	archiveSize := int64(0)
+	if archiveInfo != nil {
+		archiveSize = archiveInfo.Size()
+	}
+
+	// Truncate the original log (new empty file).
+	if err := os.Truncate(logPath, 0); err != nil {
+		return RotationResult{}, fmt.Errorf("rotation: truncate: %w", err)
+	}
+
+	return RotationResult{
+		Rotated:      true,
+		OriginalSize: info.Size(),
+		ArchivePath:  archivePath,
+		ArchiveSize:  archiveSize,
+	}, nil
+}
+
+func compressFile(src, dst string) error {
+	in, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer in.Close()
+
+	out, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer out.Close()
+
+	gz := gzip.NewWriter(out)
+	gz.Name = filepath.Base(src)
+	gz.ModTime = time.Now()
+
+	if _, err := io.Copy(gz, in); err != nil {
+		return err
+	}
+	return gz.Close()
+}