zap是uber开源的Go高性能日志库,gitlab地址

安装

go get -u go.uber.org/zap

请注意,zap仅支持两个最新的Go版本。

简单示例

格式化输出

package main

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

func main() {
    // zap.NewDevelopment 格式化输出
    logger, _ := zap.NewDevelopment()
    defer logger.Sync()
    logger.Info("无法获取网址",
        zap.String("url", "http://www.baidu.com"),
        zap.Int("attempt", 3),
        zap.Duration("backoff", time.Second),
    )
}

格式化输出打印结果:

2019-01-02T15:01:13.923+0800    INFO    spikeProxy/main.go:17   failed to fetch URL {"url": "http://www.baidu.com", "attempt": 3, "backoff": "1s"}

json 序列化输出

package main

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

func main() {
   // zap.NewProduction json序列化输出
    logger, _ := zap.NewProduction()
    defer logger.Sync()
    logger.Info("无法获取网址",
        zap.String("url", "http://www.baidu.com"),
        zap.Int("attempt", 3),
        zap.Duration("backoff", time.Second),
    )
}

json序列化输出打印结果:

{"level":"info","ts":1546413239.1466308,"caller":"spikeProxy/main.go:16","msg":"无法获取网址","url":"http://www.baidu.com","attempt":3,"backoff":1}

自定义示例

选择一个日志库除了高性能是考量的一个标准,高扩展也非常重要,例如:json key 自定义、时间格式化、日志级别等。

package main

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

func main() {
    encoderConfig := zapcore.EncoderConfig{
        TimeKey:        "time",
        LevelKey:       "level",
        NameKey:        "logger",
        CallerKey:      "caller",
        MessageKey:     "msg",
        StacktraceKey:  "stacktrace",
        LineEnding:     zapcore.DefaultLineEnding,
        EncodeLevel:    zapcore.LowercaseLevelEncoder,  // 小写编码器
        EncodeTime:     zapcore.ISO8601TimeEncoder,     // ISO8601 UTC 时间格式
        EncodeDuration: zapcore.SecondsDurationEncoder,
        EncodeCaller:   zapcore.FullCallerEncoder,      // 全路径编码器
    }

    // 设置日志级别
    atom := zap.NewAtomicLevelAt(zap.DebugLevel)

    config := zap.Config{
        Level:            atom,                                                // 日志级别
        Development:      true,                                                // 开发模式,堆栈跟踪
        Encoding:         "json",                                              // 输出格式 console 或 json
        EncoderConfig:    encoderConfig,                                       // 编码器配置
        InitialFields:    map[string]interface{}{"serviceName": "spikeProxy"}, // 初始化字段,如:添加一个服务器名称
        OutputPaths:      []string{"stdout", "./logs/spikeProxy.log"},         // 输出到指定文件 stdout(标准输出,正常颜色) stderr(错误输出,红色)
        ErrorOutputPaths: []string{"stderr"},
    }

    // 构建日志
    logger, err := config.Build()
    if err != nil {
        panic(fmt.Sprintf("log 初始化失败: %v", err))
    }
    logger.Info("log 初始化成功")

    logger.Info("无法获取网址",
        zap.String("url", "http://www.baidu.com"),
        zap.Int("attempt", 3),
        zap.Duration("backoff", time.Second),
    )
}

打印结果:

{"level":"info","time":"2019-01-02T15:38:33.778+0800","caller":"/Users/lcl/go/src/spikeProxy/main.go:54","msg":"log 初始化成功","serviceName":"spikeProxy"}
{"level":"info","time":"2019-01-02T15:38:33.778+0800","caller":"/Users/lcl/go/src/spikeProxy/main.go:56","msg":"无法获取网址","serviceName":"spikeProxy","url":"http://www.baidu.com","attempt":3,"backoff":1}

写入归档文件示例

安装 lumberjack

go get gopkg.in/natefinch/lumberjack.v2

lumberjack介绍

Lumberjack是一个Go包,用于将日志写入滚动文件。
zap 不支持文件归档,如果要支持文件按大小或者时间归档,需要使用lumberjack,lumberjack也是zap官方推荐的。

示例

package main

import (
    "go.uber.org/zap"
    "go.uber.org/zap/zapcore"
    "time"
    "gopkg.in/natefinch/lumberjack.v2"
    "os"
)

func main() {
    hook := lumberjack.Logger{
        Filename:   "./logs/spikeProxy1.log", // 日志文件路径
        MaxSize:    128,                      // 每个日志文件保存的最大尺寸 单位:M
        MaxBackups: 30,                       // 日志文件最多保存多少个备份
        MaxAge:     7,                        // 文件最多保存多少天
        Compress:   true,                     // 是否压缩
    }

    encoderConfig := zapcore.EncoderConfig{
        TimeKey:        "time",
        LevelKey:       "level",
        NameKey:        "logger",
        CallerKey:      "linenum",
        MessageKey:     "msg",
        StacktraceKey:  "stacktrace",
        LineEnding:     zapcore.DefaultLineEnding,
        EncodeLevel:    zapcore.LowercaseLevelEncoder,  // 小写编码器
        EncodeTime:     zapcore.ISO8601TimeEncoder,     // ISO8601 UTC 时间格式
        EncodeDuration: zapcore.SecondsDurationEncoder, //
        EncodeCaller:   zapcore.FullCallerEncoder,      // 全路径编码器
        EncodeName:     zapcore.FullNameEncoder,
    }

    // 设置日志级别
    atomicLevel := zap.NewAtomicLevel()
    atomicLevel.SetLevel(zap.InfoLevel)

    core := zapcore.NewCore(
        zapcore.NewJSONEncoder(encoderConfig),                                           // 编码器配置
        zapcore.NewMultiWriteSyncer(zapcore.AddSync(os.Stdout), zapcore.AddSync(&hook)), // 打印到控制台和文件
        atomicLevel,                                                                     // 日志级别
    )

    // 开启开发模式,堆栈跟踪
    caller := zap.AddCaller()
    // 开启文件及行号
    development := zap.Development()
    // 设置初始化字段
    filed := zap.Fields(zap.String("serviceName", "serviceName"))
    // 构造日志
    logger := zap.New(core, caller, development, filed)

    logger.Info("log 初始化成功")
    logger.Info("无法获取网址",
        zap.String("url", "http://www.baidu.com"),
        zap.Int("attempt", 3),
        zap.Duration("backoff", time.Second))
}

控制台打印结果:

{"level":"info","time":"2019-01-02T16:14:43.608+0800","linenum":"/Users/lcl/go/src/spikeProxy/main.go:56","msg":"log 初始化成功","serviceName":"serviceName"}
{"level":"info","time":"2019-01-02T16:14:43.608+0800","linenum":"/Users/lcl/go/src/spikeProxy/main.go:57","msg":"无法获取网址","serviceName":"serviceName","url":"http://www.baidu.com","attempt":3,"backoff":1}

文件打印结果:

{"level":"info","time":"2019-01-02T16:14:43.608+0800","linenum":"/Users/lcl/go/src/spikeProxy/main.go:56","msg":"log 初始化成功","serviceName":"serviceName"}
{"level":"info","time":"2019-01-02T16:14:43.608+0800","linenum":"/Users/lcl/go/src/spikeProxy/main.go:57","msg":"无法获取网址","serviceName":"serviceName","url":"http://www.baidu.com","attempt":3,"backoff":1}

结语

目前关于zap的资料很少,都需要自己动手总结,在使用过程中有更多的使用方式我也会持续更新,有问题请在下方留言,我会尽快回复的。