open-vault/helper/logging/logfile.go

151 lines
3.5 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
package logging
import (
"fmt"
"os"
"path/filepath"
"sort"
"strconv"
"strings"
"sync"
"time"
"github.com/hashicorp/go-multierror"
)
var now = time.Now
type LogFile struct {
// Name of the log file
fileName string
// Path to the log file
logPath string
// duration between each file rotation operation
duration time.Duration
// lastCreated represents the creation time of the latest log
lastCreated time.Time
// fileInfo is the pointer to the current file being written to
fileInfo *os.File
// maxBytes is the maximum number of desired bytes for a log file
maxBytes int
// bytesWritten is the number of bytes written in the current log file
bytesWritten int64
// Max rotated files to keep before removing them.
maxArchivedFiles int
// acquire is the mutex utilized to ensure we have no concurrency issues
acquire sync.Mutex
}
// Write is used to implement io.Writer
func (l *LogFile) Write(b []byte) (n int, err error) {
l.acquire.Lock()
defer l.acquire.Unlock()
// Create a new file if we have no file to write to
if l.fileInfo == nil {
if err := l.openNew(); err != nil {
return 0, err
}
} else if err := l.rotate(); err != nil { // Check for the last contact and rotate if necessary
return 0, err
}
bytesWritten, err := l.fileInfo.Write(b)
if bytesWritten > 0 {
l.bytesWritten += int64(bytesWritten)
}
return bytesWritten, err
}
func (l *LogFile) fileNamePattern() string {
// Extract the file extension
fileExt := filepath.Ext(l.fileName)
// If we have no file extension we append .log
if fileExt == "" {
fileExt = ".log"
}
// Remove the file extension from the filename
return strings.TrimSuffix(l.fileName, fileExt) + "-%s" + fileExt
}
func (l *LogFile) openNew() error {
fileNamePattern := l.fileNamePattern()
createTime := now()
newFileName := fmt.Sprintf(fileNamePattern, strconv.FormatInt(createTime.UnixNano(), 10))
newFilePath := filepath.Join(l.logPath, newFileName)
// Try creating a file. We truncate the file because we are the only authority to write the logs
filePointer, err := os.OpenFile(newFilePath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0o640)
if err != nil {
return err
}
// New file, new 'bytes' tracker, new creation time :) :)
l.fileInfo = filePointer
l.lastCreated = createTime
l.bytesWritten = 0
return nil
}
func (l *LogFile) rotate() error {
// Get the time from the last point of contact
timeElapsed := time.Since(l.lastCreated)
// Rotate if we hit the byte file limit or the time limit
if (l.bytesWritten >= int64(l.maxBytes) && (l.maxBytes > 0)) || timeElapsed >= l.duration {
if err := l.fileInfo.Close(); err != nil {
return err
}
if err := l.pruneFiles(); err != nil {
return err
}
return l.openNew()
}
return nil
}
func (l *LogFile) pruneFiles() error {
if l.maxArchivedFiles == 0 {
return nil
}
pattern := filepath.Join(l.logPath, fmt.Sprintf(l.fileNamePattern(), "*"))
matches, err := filepath.Glob(pattern)
if err != nil {
return err
}
switch {
case l.maxArchivedFiles < 0:
return removeFiles(matches)
case len(matches) < l.maxArchivedFiles:
return nil
}
sort.Strings(matches)
last := len(matches) - l.maxArchivedFiles
return removeFiles(matches[:last])
}
func removeFiles(files []string) (err error) {
for _, file := range files {
if fileError := os.Remove(file); fileError != nil {
err = multierror.Append(err, fmt.Errorf("error removing file %s: %v", file, fileError))
}
}
return err
}