caddy/modules/logging/filewriter.go

// Copyright 2015 Matthew Holt and The Caddy 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 logging

import (
	"io"
	"os"
	"path/filepath"

	"github.com/caddyserver/caddy/v2"
	"gopkg.in/natefinch/lumberjack.v2"
)

func init() {
	caddy.RegisterModule(FileWriter{})
}

// FileWriter can write logs to files.
type FileWriter struct {
	Filename      string `json:"filename,omitempty"`
	Roll          *bool  `json:"roll,omitempty"`
	RollSizeMB    int    `json:"roll_size_mb,omitempty"`
	RollCompress  *bool  `json:"roll_gzip,omitempty"`
	RollLocalTime bool   `json:"roll_local_time,omitempty"`
	RollKeep      int    `json:"roll_keep,omitempty"`
	RollKeepDays  int    `json:"roll_keep_days,omitempty"`
}

// CaddyModule returns the Caddy module information.
func (FileWriter) CaddyModule() caddy.ModuleInfo {
	return caddy.ModuleInfo{
		Name: "caddy.logging.writers.file",
		New:  func() caddy.Module { return new(FileWriter) },
	}
}

func (fw FileWriter) String() string {
	fpath, err := filepath.Abs(fw.Filename)
	if err == nil {
		return fpath
	}
	return fw.Filename
}

// WriterKey returns a unique key representing this fw.
func (fw FileWriter) WriterKey() string {
	return "file:" + fw.Filename
}

// OpenWriter opens a new file writer.
func (fw FileWriter) OpenWriter() (io.WriteCloser, error) {
	// roll log files by default
	if fw.Roll == nil || *fw.Roll == true {
		if fw.RollSizeMB == 0 {
			fw.RollSizeMB = 100
		}
		if fw.RollCompress == nil {
			compress := true
			fw.RollCompress = &compress
		}
		if fw.RollKeep == 0 {
			fw.RollKeep = 10
		}
		if fw.RollKeepDays == 0 {
			fw.RollKeepDays = 90
		}
		return &lumberjack.Logger{
			Filename:   fw.Filename,
			MaxSize:    fw.RollSizeMB,
			MaxAge:     fw.RollKeepDays,
			MaxBackups: fw.RollKeep,
			LocalTime:  fw.RollLocalTime,
			Compress:   *fw.RollCompress,
		}, nil
	}

	// otherwise just open a regular file
	return os.OpenFile(fw.Filename, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0666)
}