`Go`日志管理

`log`标准库

配置设置

log.SetPrefix(stirng)：设置前缀
log.Prefix() string：获取前缀

记录日志

log的封装较为简单，包含以下三类常用方法
log.Print("INFO")：记录信息
log.Panic("PANIC")：记录信息后抛出panic
log.Fatal("FATAL)：记录信息后调用os.exit(1)
它们都有对应的ln版本

`zap`

`zap`配置定义

zap.Config定义：

go
import "go.uber.org/zap/zapcore"

type Config struct {
	// Level is the minimum enabled logging level.
	// 运行时修改会修改全部 logger 的 Level
	Level AtomicLevel `json:"level" yaml:"level"`
	// 开发模式, zap 在提供默认配置时会参考该值
	// 调用对应的 NewProductionXxxConfig() / NewDevelopmentXxxConfig()
	Development bool `json:"development" yaml:"development"`
	// (默认即可) 默认记录 调用者 所有场景
	DisableCaller bool `json:"disableCaller" yaml:"disableCaller"`
	// (默认即可) 默认记录 堆栈 WarnLevel-Development / ErrorLevel-Production
	DisableStacktrace bool `json:"disableStacktrace" yaml:"disableStacktrace"`
	// (默认即可) 生产环境下有采样, 用于限流高频日志
	Sampling *SamplingConfig `json:"sampling" yaml:"sampling"`
	// 编码 "json" (json风格 建议生产环境) / "console" (控制台风格 建议开发环境)
	Encoding string `json:"encoding" yaml:"encoding"`
	// 编码器配置
	EncoderConfig zapcore.EncoderConfig `json:"encoderConfig" yaml:"encoderConfig"`
	// 输出路径 "stdout" 表示标准输出 不会自动创建不存在的目录
	OutputPaths []string `json:"outputPaths" yaml:"outputPaths"`
	// 错误日志输出路径 "stderr" 表示标准错误流
	ErrorOutputPaths []string `json:"errorOutputPaths" yaml:"errorOutputPaths"`
	// 自定义的针对所有日志都默认追加的输出
	InitialFields map[string]interface{} `json:"initialFields" yaml:"initialFields"`
}

zapcore.EncoderConfig定义：

go
import "io"

type EncoderConfig struct {
	// Set the keys used for each log entry. If any key is empty, that portion
	// of the entry is omitted.
	// 信息 键
	MessageKey string `json:"messageKey" yaml:"messageKey"`
	// 级别 键
	LevelKey string `json:"levelKey" yaml:"levelKey"`
	// 时间戳 键
	TimeKey string `json:"timeKey" yaml:"timeKey"`
	//
	NameKey string `json:"nameKey" yaml:"nameKey"`
	// 调用者 键
	CallerKey string `json:"callerKey" yaml:"callerKey"`
	//
	FunctionKey string `json:"functionKey" yaml:"functionKey"`
	// 调用栈 键
	StacktraceKey string `json:"stacktraceKey" yaml:"stacktraceKey"`
	//
	SkipLineEnding bool `json:"skipLineEnding" yaml:"skipLineEnding"`
	//
	LineEnding string `json:"lineEnding" yaml:"lineEnding"`
	// Configure the primitive representations of common complex types. For
	// example, some users may want all time.Times serialized as floating-point
	// seconds since epoch, while others may prefer ISO8601 strings.
	// 日志级别 编码器
	EncodeLevel LevelEncoder `json:"levelEncoder" yaml:"levelEncoder"`
	// 时间戳 编码器
	EncodeTime TimeEncoder `json:"timeEncoder" yaml:"timeEncoder"`
	//
	EncodeDuration DurationEncoder `json:"durationEncoder" yaml:"durationEncoder"`
	// 调用者 编码器
	EncodeCaller CallerEncoder `json:"callerEncoder" yaml:"callerEncoder"`
	// Unlike the other primitive type encoders, EncodeName is optional. The
	// zero value falls back to FullNameEncoder.
	EncodeName NameEncoder `json:"nameEncoder" yaml:"nameEncoder"`
	// Configure the encoder for interface{} type objects.
	// If not provided, objects are encoded using json.Encoder
	NewReflectedEncoder func(io.Writer) ReflectedEncoder `json:"-" yaml:"-"`
	// Configures the field separator used by the console encoder. Defaults to tab.
	// 控制台 不同字段的分隔符 默认为 tab
	ConsoleSeparator string `json:"consoleSeparator" yaml:"consoleSeparator"`
}

`zap`默认配置

zap.NewProduction() (*zap.Logger, error)：获取生产环境下的默认Logger实例
zap.NewDevelopment() (*zap.Logger, error)：获取开发环境下的默认Logger实例
zap.NewProductionConfig() zap.Config：获取生产环境的默认配置
zap.NewDevelopmentConfig() zap.Config：获取开发环境的默认配置

自定义配置(`zapcore`)

zap的默认配置很多时候十分死板，而zap提供的获取Logger的方法不支持自定义编码器配置与自定义写接口，因此需要使用zapcore
甚至zap提供的默认配置无法通过viper管理
zapcore.NewProductionEncoderConfig() zapcore.EncoderConfig：获取生产环境的编码器配置，可在此基础上作修改
zapcore.NewDevelopmentEncoderConfig() zapcore.EncoderConfig：获取开发环境的编码器配置
zapcore.NewJSONEncoder(EncoderConfig) zapcore.Encoder：获取输出JSON格式的编码器
zapcore.NewConsoleEncoder(EncoderConfig) zapcore.Encoder：获取输出控制台、更易读日志的编码器
zapcore.Level：日志级别，实现了zapcore.LevelEnabler接口
zap和zapcore提供了日志级别的快捷枚举：
- DebugLevel
- InfoLevel
- WarnLevel
- ErrorLevel
- DPanicLevel
- PanicLevel
- FatalLevel
zapcore.AddSync(w io.Writer) zapcore.WriteSyncer：将一个io.Writer包装成WriteSyncer
zapcore.NewMultiWriteSyncer(ws ...zapcore.WriteSyncer) zapcore.WriteSyncer：将多个WriteSyncer包装成一个WriteSyncer，在写入时会同步写入所有的ws，需要多路径输出时使用
zapcore.NewCore(enc zapcore.Encoder, ws zapcore.WriteSyncer, enab zapcore.LevelEnabler) zapcore.Core：将编码器、写入器、级别限制包装成zapcore.Core，需要分级别输出时可以创建多个核心
zapcore.NewTee(...zapcore.Core) zapcore.Core：将多个核心包装成一个核心，需要分级别输出时使用
zap.New(zapcore.Core, ...zap.Option) *zap.Logger：使用给定的核心创建Logger对象，不会有错误抛出

`lumberjack`

lumberjack只有一个核心用法：以zap作为后端，提供日志轮转功能，包括日志过大分割、日志定时丢弃、日志压缩

创建lumberjack.Logger：

go
logRotator := &lumberjack.Logger{
  Filename:   "/var/log/myapp/app.log", // 日志文件路径
  MaxSize:    100,    // 单位: MB, 单个文件最大尺寸, 超过即分割
  MaxBackups: 30,     // 保留的旧日志文件最大数量
  MaxAge:     90,     // 单位: 天, 保留旧日志的最大天数
  Compress:   true,   // 是否压缩归档的旧日志文件
  LocalTime:  true,   // 使用本地时间命名旧日志文件 (默认使用 UTC)
}

通过zapcore.AddSync(&lumberjack.Logger{...})将其转换为zapcore.WriteSyncer

自定义编码器格式

EncodeTime：type TimeEncoder func(time.Time, zapcore.PrimitiveArrayEncoder)
EncodeLevel：type LevelEncoder func(zapcore.Level, zapcore.PrimitiveArrayEncoder)
EncodeDuration：type DurationEncoder func(time.Duration, zapcore.PrimitiveArrayEncoder)
EncodeCaller：type CallerEncoder func(zapcore.EntryCaller, zapcore.PrimitiveArrayEncoder)
EncodeName：type NameEncoder func(string, zapcore.PrimitiveArrayEncoder)
在自定义时，直接调用zapcore.PrimitiveArrayEncoder接口的方法，包含一系列AppendXxx()方法，其中Xxx可以是数值类型和字符串类型

`zap.Option`

zap.AddCaller()：在日志中添加调用者的文件名和行号
zap.AddCallerSkip(skip int)：设置调用栈信息跳过的层数
zap.AddStacktrace(lvl zapcore.Level)：为指定级别及以上的日志记录堆栈跟踪
zap.Fields(fields ...Field)：向Logger添加固定的上下文字段
zap.Development()：启用开发模式（更易读的输出、禁用采样等）
zap.ErrorOutput(w zapcore.WriteSyncer)：设置内部错误（如编码失败）的输出位置
zap.WrapCore(f func(zapcore.Core) zapcore.Core)：用于包装或替换底层的Core
zap.Hooks(hooks ...func(zapcore.Entry) error)：为每条日志添加钩子函数
zap.IncreaseLevel(lvl zapcore.LevelEnabler)：提高日志记录的最低级别
zap.WithClock(clock zapcore.Clock)：自定义日志时间来源
zap.WithFatalHook(hook zapcore.CheckWriteHook)：为Fatal级别的日志设置钩子
zap.WithPanicHook(hook func(entry zapcore.Entry) error)：为Panic级别的日志设置钩子

`Logger`使用

Logger本身很简单，对应每种级别有对应的方法（七种级别），Logger的性能较好，方法签名如下：
Xxx(msg string, ...zap.Field)：本条日志的信息是msg，后面附带一系列字段（强类型）

zap.Field：

go
const (
	// UnknownType is the default field type. Attempting to add it to an encoder will panic.
	UnknownType FieldType = iota
	// ArrayMarshalerType indicates that the field carries an ArrayMarshaler.
	ArrayMarshalerType
	// ObjectMarshalerType indicates that the field carries an ObjectMarshaler.
	ObjectMarshalerType
	// BinaryType indicates that the field carries an opaque binary blob.
	BinaryType
	// BoolType indicates that the field carries a bool.
	BoolType
	// ByteStringType indicates that the field carries UTF-8 encoded bytes.
	ByteStringType
	// Complex128Type indicates that the field carries a complex128.
	Complex128Type
	// Complex64Type indicates that the field carries a complex64.
	Complex64Type
	// DurationType indicates that the field carries a time.Duration.
	DurationType
	// Float64Type indicates that the field carries a float64.
	Float64Type
	// Float32Type indicates that the field carries a float32.
	Float32Type
	// Int64Type indicates that the field carries an int64.
	Int64Type
	// Int32Type indicates that the field carries an int32.
	Int32Type
	// Int16Type indicates that the field carries an int16.
	Int16Type
	// Int8Type indicates that the field carries an int8.
	Int8Type
	// StringType indicates that the field carries a string.
	StringType
	// TimeType indicates that the field carries a time.Time that is
	// representable by a UnixNano() stored as an int64.
	TimeType
	// TimeFullType indicates that the field carries a time.Time stored as-is.
	TimeFullType
	// Uint64Type indicates that the field carries a uint64.
	Uint64Type
	// Uint32Type indicates that the field carries a uint32.
	Uint32Type
	// Uint16Type indicates that the field carries a uint16.
	Uint16Type
	// Uint8Type indicates that the field carries a uint8.
	Uint8Type
	// UintptrType indicates that the field carries a uintptr.
	UintptrType
	// ReflectType indicates that the field carries an interface{}, which should
	// be serialized using reflection.
	ReflectType
	// NamespaceType signals the beginning of an isolated namespace. All
	// subsequent fields should be added to the new namespace.
	NamespaceType
	// StringerType indicates that the field carries a fmt.Stringer.
	StringerType
	// ErrorType indicates that the field carries an error.
	ErrorType
	// SkipType indicates that the field is a no-op.
	SkipType

	// InlineMarshalerType indicates that the field carries an ObjectMarshaler
	// that should be inlined.
	InlineMarshalerType
)

每种类型都对应一个方法，Xxx(key string, value Type) zap.Field，需要提供键、对应的强类型的值

Logger.Sugared() *zap.SugaredLogger：获取一个性能较差，但是支持log标准库风格的日志器，即SugaredLogger提供Xxx(string)和Xxxf(string, ...any)

例子配置

viper配置映射及级别配置：

go
import "go.uber.org/zap/zapcore"

const (
	DebugLevel   = "debug"
	InfoLevel    = "info"
	FatalLevel   = "fatal"
	WarnLevel    = "warn"
	ErrorLevel   = "error"
	PanicLevel   = "panic"
	DefaultLevel = "debug"
)

type ZapConfig struct {
	Level            string         `mapstruct:"level"`
	Development      bool           `mapstruct:"development"`
	Encoding         string         `mapstruct:"encoding"`
	OutputPaths      []string       `mapstruct:"outputPaths"`
	ErrorOutputPaths []string       `mapstruct:"errorOutputPaths"`
	InitialFields    map[string]any `mapstruct:"initialFields"`
}

func zapLevelEnabler(cfg *config.ZapConfig) zapcore.LevelEnabler {
	level, ok := levelMap[cfg.Level]
	if ok {
		return level
	} else {
		return levelMap[config.DefaultLevel]
	}
}

配置编码器，这里使用的就是默认的

go
import (
	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"
)

func zapEncoderConfig(cfg *config.ZapConfig) zapcore.EncoderConfig {
	var encoderCfg zapcore.EncoderConfig
	if cfg.Development {
		encoderCfg = zap.NewDevelopmentEncoderConfig()
	} else {
		encoderCfg = zap.NewProductionEncoderConfig()
	}
	return encoderCfg
}

func zapEncoder(cfg *config.ZapConfig) zapcore.Encoder {
	encoderCfg := zapEncoderConfig(cfg)
	switch cfg.Encoding {
	case "json":
		return zapcore.NewJSONEncoder(encoderCfg)
	case "console":
		return zapcore.NewConsoleEncoder(encoderCfg)
	default:
		return zapcore.NewConsoleEncoder(encoderCfg)
	}
}

WriteSyncer配置：

go
import (
	"os"
	"strings"

	"github.com/natefinch/lumberjack"
	"go.uber.org/zap/zapcore"
)

func newWriterSyncer(paths []string) zapcore.WriteSyncer {
	syncers := make([]zapcore.WriteSyncer, 0, len(paths))
	for _, path := range paths {
		var ws zapcore.WriteSyncer
		switch {
		case strings.ToLower(path) == "stdout":
			ws = zapcore.AddSync(os.Stdout)
		case strings.ToLower(path) == "stderr":
			ws = zapcore.AddSync(os.Stderr)
		default:
			lumberjackLogger := &lumberjack.Logger{
				Filename:   path,
				MaxSize:    100,
				MaxBackups: 30,
				MaxAge:     90,
				Compress:   true,
			}
			ws = zapcore.AddSync(lumberjackLogger)
		}
		syncers = append(syncers, ws)
	}
	return zapcore.NewMultiWriteSyncer(syncers...)
}

func zapWriterSyncer(cfg *config.ZapConfig) (zapcore.WriteSyncer, zapcore.WriteSyncer) {
	return newWriterSyncer(cfg.OutputPaths), newWriterSyncer(cfg.ErrorOutputPaths)
}

Go日志管理#

log标准库#

配置设置#

记录日志#

zap#

zap配置定义#

zap默认配置#

自定义配置(zapcore)#

lumberjack#

自定义编码器格式#

zap.Option#

Logger使用#

例子配置#

`Go`日志管理

`log`标准库

配置设置

记录日志

`zap`

`zap`配置定义

`zap`默认配置

自定义配置(`zapcore`)

`lumberjack`

自定义编码器格式

`zap.Option`

`Logger`使用

例子配置