（Zap日志框架，Go）一次初始化日志并从其他Go文件中重用（已解决）

Question

I'm trying to migrate my application from the beautiful Logrus (very helpful for debug) and introducing the Uber log framework Zap.

With Logrus, i can initialize the logger only once and reuse it from other Go file, an example:

package main
import(
    // Print filename on log
    filename "github.com/onrik/logrus/filename"
    // Very nice log library
    log "github.com/sirupsen/logrus"
)

func main(){

// ==== SET LOGGING
    Formatter := new(log.TextFormatter) //#TODO: Formatter have to be inserted in `configuration` in order to dynamically change debug level [at runtime?]
    Formatter.TimestampFormat = "15-01-2018 15:04:05.000000"
    Formatter.FullTimestamp = true
    Formatter.ForceColors = true
    log.AddHook(filename.NewHook()) // Print filename + line at every log
    log.SetFormatter(Formatter)

}

From other Go file, i'm able to reuse that logger without any other initialization:

// VerifyCommandLineInput is delegated to manage the inputer parameter provide with the input flag from command line
func VerifyCommandLineInput() datastructures.Configuration {
    log.Debug("VerifyCommandLineInput | Init a new configuration from the conf file")
    c := flag.String("config", "./conf/test.json", "Specify the configuration file.")
    flag.Parse()
    if strings.Compare(*c, "") == 0 {
        log.Fatal("VerifyCommandLineInput | Call the tool using --config conf/config.json")
    }
    file, err := os.Open(*c)
    if err != nil {
        log.Fatal("VerifyCommandLineInput | can't open config file: ", err)
    }
    defer file.Close()
    decoder := json.NewDecoder(file)
    cfg := datastructures.Configuration{}
    err = decoder.Decode(&cfg)
    if err != nil {
        log.Fatal("VerifyCommandLineInput | can't decode config JSON: ", err)
    }
    log.Debug("VerifyCommandLineInput | Conf loaded -> ", cfg)

    return cfg
}

My question is:
Using the Zap log framework, how can i initialize the log in the main function and use that logger from the other Go file?

---

Solution:

Initialize a new log and set as global as pointed by @Mikhail.

package main

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

func initZapLog() *zap.Logger {
    config := zap.NewDevelopmentConfig()
    config.EncoderConfig.EncodeLevel = zapcore.CapitalColorLevelEncoder
    config.EncoderConfig.TimeKey = "timestamp"
    config.EncoderConfig.EncodeTime = zapcore.ISO8601TimeEncoder
    logger, _ := config.Build()
    return logger
}

func main() {

    loggerMgr := initZapLog()
    zap.ReplaceGlobals(loggerMgr)
    defer loggerMgr.Sync() // flushes buffer, if any
    logger := loggerMgr.Sugar()
    logger.Debug("START!")
    db2.GetToken(`alessio`, `savi`, `pass`)
    datastructure.LoadConfiguration()
}

Than you can use the logger in the other Go file:

func GetToken(url, user, pass string) string {
    var User datastructure.User
    var data string
    var jsonData []byte

    User.User = user
    User.Pass = pass
    jsonData, err := json.Marshal(User)
    if err != nil {
        zap.S().Errorw("Error during marshalling...", err)
        return ""
    }
    data = string(jsonData)
    zap.S().Info("Data encoded => ", data)
    return ""
}

Answer 1

You can set up your logger in the main function and call https://godoc.org/go.uber.org/zap#ReplaceGlobals to use it as a default global logger.