Go 语言之自定义 zap 日志

zap 日志：https://github.com/uber-go/zap

一、日志写入文件

• zap.NewProduction、zap.NewDevelopment 是预设配置好的。
• zap.New 可自定义配置

zap.New源码

这是构造Logger最灵活的方式，但也是最冗长的方式。

对于典型的用例，高度固执己见的预设(NewProduction、NewDevelopment和NewExample)或Config结构体更方便。

// New constructs a new Logger from the provided zapcore.Core and Options. If
// the passed zapcore.Core is nil, it falls back to using a no-op
// implementation.
//
// This is the most flexible way to construct a Logger, but also the most
// verbose. For typical use cases, the highly-opinionated presets
// (NewProduction, NewDevelopment, and NewExample) or the Config struct are
// more convenient.
//
// For sample code, see the package-level AdvancedConfiguration example.
func New(core zapcore.Core, options ...Option) *Logger {
	if core == nil {
		return NewNop()
	}
	log := &Logger{
		core:        core,
		errorOutput: zapcore.Lock(os.Stderr),
		addStack:    zapcore.FatalLevel + 1,
		clock:       zapcore.DefaultClock,
	}
	return log.WithOptions(options...)
}

zapcore.Core 源码

// Core is a minimal, fast logger interface. It's designed for library authors
// to wrap in a more user-friendly API.
type Core interface {
	LevelEnabler

	// With adds structured context to the Core.
	With([]Field) Core
	// Check determines whether the supplied Entry should be logged (using the
	// embedded LevelEnabler and possibly some extra logic). If the entry
	// should be logged, the Core adds itself to the CheckedEntry and returns
	// the result.
	//
	// Callers must use Check before calling Write.
	Check(Entry, *CheckedEntry) *CheckedEntry
	// Write serializes the Entry and any Fields supplied at the log site and
	// writes them to their destination.
	//
	// If called, Write should always log the Entry and Fields; it should not
	// replicate the logic of Check.
	Write(Entry, []Field) error
	// Sync flushes buffered logs (if any).
	Sync() error
}

zapcore.AddSync(file) 源码解析

func AddSync(w io.Writer) WriteSyncer {
	switch w := w.(type) {
	case WriteSyncer:
		return w
	default:
		return writerWrapper{w}
	}
}

type writerWrapper struct {
	io.Writer
}

func (w writerWrapper) Sync() error {
	return nil
}

type WriteSyncer interface {
	io.Writer
	Sync() error
}

日志级别

// A Level is a logging priority. Higher levels are more important.
type Level int8

const (
	// DebugLevel logs are typically voluminous, and are usually disabled in
	// production.
	DebugLevel Level = iota - 1
	// InfoLevel is the default logging priority.
	InfoLevel
	// WarnLevel logs are more important than Info, but don't need individual
	// human review.
	WarnLevel
	// ErrorLevel logs are high-priority. If an application is running smoothly,
	// it shouldn't generate any error-level logs.
	ErrorLevel
	// DPanicLevel logs are particularly important errors. In development the
	// logger panics after writing the message.
	DPanicLevel
	// PanicLevel logs a message, then panics.
	PanicLevel
	// FatalLevel logs a message, then calls os.Exit(1).
	FatalLevel

	_minLevel = DebugLevel
	_maxLevel = FatalLevel

	// InvalidLevel is an invalid value for Level.
	//
	// Core implementations may panic if they see messages of this level.
	InvalidLevel = _maxLevel + 1
)

实操

package main

import (
	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"
	"net/http"
	"os"
)

// 定义一个全局 logger 实例
// Logger提供快速、分级、结构化的日志记录。所有方法对于并发使用都是安全的。
// Logger是为每一微秒和每一个分配都很重要的上下文设计的，
// 因此它的API有意倾向于性能和类型安全，而不是简便性。
// 对于大多数应用程序，SugaredLogger在性能和人体工程学之间取得了更好的平衡。
var logger *zap.Logger

// SugaredLogger将基本的Logger功能封装在一个较慢但不那么冗长的API中。任何Logger都可以通过其Sugar方法转换为sugardlogger。
//与Logger不同，SugaredLogger并不坚持结构化日志记录。对于每个日志级别，它公开了四个方法:
//   - methods named after the log level for log.Print-style logging
//   - methods ending in "w" for loosely-typed structured logging
//   - methods ending in "f" for log.Printf-style logging
//   - methods ending in "ln" for log.Println-style logging

// For example, the methods for InfoLevel are:
//
//	Info(...any)           Print-style logging
//	Infow(...any)          Structured logging (read as "info with")
//	Infof(string, ...any)  Printf-style logging
//	Infoln(...any)         Println-style logging
var sugarLogger *zap.SugaredLogger

func main() {
	// 初始化
	InitLogger()
	// Sync调用底层Core的Sync方法，刷新所有缓冲的日志条目。应用程序在退出之前应该注意调用Sync。
	// 在程序退出之前，把缓冲区里的日志刷到磁盘上
	defer logger.Sync()
	simpleHttpGet("www.baidu.com")
	simpleHttpGet("http://www.baidu.com")
}

func InitLogger() {
	writeSyncer := getLogWriter()
	encoder := getEncoder()
	// NewCore创建一个向WriteSyncer写入日志的Core。

	// A WriteSyncer is an io.Writer that can also flush any buffered data. Note
	// that *os.File (and thus, os.Stderr and os.Stdout) implement WriteSyncer.

	// LevelEnabler决定在记录消息时是否启用给定的日志级别。
	// Each concrete Level value implements a static LevelEnabler which returns
	// true for itself and all higher logging levels. For example WarnLevel.Enabled()
	// will return true for WarnLevel, ErrorLevel, DPanicLevel, PanicLevel, and
	// FatalLevel, but return false for InfoLevel and DebugLevel.
	core := zapcore.NewCore(encoder, writeSyncer, zapcore.DebugLevel)

	// New constructs a new Logger from the provided zapcore.Core and Options. If
	// the passed zapcore.Core is nil, it falls back to using a no-op
	// implementation.
	logger = zap.New(core)
	// Sugar封装了Logger，以提供更符合人体工程学的API，但速度略慢。糖化一个Logger的成本非常低，
	// 因此一个应用程序同时使用Loggers和SugaredLoggers是合理的，在性能敏感代码的边界上在它们之间进行转换。
	sugarLogger = logger.Sugar()
}

func getEncoder() zapcore.Encoder {
	// NewJSONEncoder创建了一个快速、低分配的JSON编码器。编码器适当地转义所有字段键和值。
	// NewProductionEncoderConfig returns an opinionated EncoderConfig for
	// production environments.
	return zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig())
}

func getLogWriter() zapcore.WriteSyncer {
	// Create创建或截断指定文件。如果文件已经存在，它将被截断。如果该文件不存在，则以模式0666(在umask之前)创建。
	// 如果成功，返回的File上的方法可以用于IO;关联的文件描述符模式为O_RDWR。如果有一个错误，它的类型将是PathError。
	file, _ := os.Create("./test.log")
	// AddSync converts an io.Writer to a WriteSyncer. It attempts to be
	// intelligent: if the concrete type of the io.Writer implements WriteSyncer,
	// we'll use the existing Sync method. If it doesn't, we'll add a no-op Sync.
	return zapcore.AddSync(file)
}

func simpleHttpGet(url string) {
	// Get向指定的URL发出Get命令。如果响应是以下重定向代码之一，则Get跟随重定向，最多可重定向10个:
	//	301 (Moved Permanently)
	//	302 (Found)
	//	303 (See Other)
	//	307 (Temporary Redirect)
	//	308 (Permanent Redirect)
	// Get is a wrapper around DefaultClient.Get.
	// 使用NewRequest和DefaultClient.Do来发出带有自定义头的请求。
	resp, err := http.Get(url)
	if err != nil {
		// Error在ErrorLevel记录消息。该消息包括在日志站点传递的任何字段，以及日志记录器上积累的任何字段。
		//logger.Error(

		// 错误使用fmt。以Sprint方式构造和记录消息。
		sugarLogger.Error(
			"Error fetching url..",
			zap.String("url", url), // 字符串用给定的键和值构造一个字段。
			zap.Error(err))         // // Error is shorthand for the common idiom NamedError("error", err).
	} else {
		// Info以infollevel记录消息。该消息包括在日志站点传递的任何字段，以及日志记录器上积累的任何字段。
		//logger.Info("Success..",

		// Info使用fmt。以Sprint方式构造和记录消息。
		sugarLogger.Info("Success..",
			zap.String("statusCode", resp.Status),
			zap.String("url", url))
		resp.Body.Close()
	}
}

运行

Code/go/zap_demo via 

标签：zapcore,log,自定义,url,Go,日志,Logger,zap	

From： https://www.cnblogs.com/QiaoPengjun/p/17487453.html