golang自带日志框架功能比较简单，仅提供print、panic、fatal三个方法，对于常规的日志切割等功能并未提供支持。
这里推荐使用sirupsen/logrus日志库。
logrus feature
- 结构化、可插拔的日志模块
- 完全兼容官方log库接口
- Field机制
- 可扩展的HOOK机制
- TEXT与JSON两种可选格式
简单使用示例
std Logger
与官方log类似，logrus也提供了一个名为std的标准logger，对外导出的各类方法直接使用std记录日志，一般可按如下方式使用
package main
import log "github.com/sirupsen/logrus"
func main() {
log.Info("hello, world.")
}
自建Logger实例
package main
import (
"os"
"github.com/sirupsen/logrus"
)
// Create a new instance of the logger. You can have any number of instances.
var log = logrus.New()
func main() {
// The API for setting attributes is a little different than the package level
// exported logger. See Godoc.
log.Out = os.Stdout
// You could set this to any `io.Writer` such as a file
// file, err := os.OpenFile("logrus.log", os.O_CREATE|os.O_WRONLY, 0666)
// if err == nil {
// log.Out = file
// } else {
// log.Info("Failed to log to file, using default stderr")
// }
log.WithFields(logrus.Fields{
"animal": "walrus",
"size": 10,
}).Info("A group of walrus emerges from the ocean")
}
输出到本地文件系统
下面示例代码，通过一个hook将日志输出到本地文件系统中，并提供日志切割功能
import (
"github.com/lestrrat/go-file-rotatelogs"
"github.com/rifflock/lfshook"
log "github.com/sirupsen/logrus"
"time"
"os"
"github.com/pkg/errors"
"path"
)
// config logrus log to local filesystem, with file rotation
func ConfigLocalFilesystemLogger(logPath string, logFileName string, maxAge time.Duration, rotationTime time.Duration) {
baseLogPaht := path.Join(logPath, logFileName)
writer, err := rotatelogs.New(
baseLogPaht+".%Y%m%d%H%M",
rotatelogs.WithLinkName(baseLogPaht), // 生成软链，指向最新日志文件
rotatelogs.WithMaxAge(maxAge), // 文件最大保存时间
rotatelogs.WithRotationTime(rotationTime), // 日志切割时间间隔
)
if err != nil {
log.Errorf("config local file system logger error. %+v", errors.WithStack(err))
}
lfHook := lfshook.NewHook(lfshook.WriterMap{
log.DebugLevel: writer, // 为不同级别设置不同的输出目的
log.InfoLevel: writer,
log.WarnLevel: writer,
log.ErrorLevel: writer,
log.FatalLevel: writer,
log.PanicLevel: writer,
})
log.AddHook(lfHook)
}
输出到MQ或ES
如下示例代码通过hook将日志输出到amqp消息队列，或者es中。
import (
"github.com/vladoatanasov/logrus_amqp"
"gopkg.in/olivere/elastic.v5"
"gopkg.in/sohlich/elogrus.v2"
log "github.com/sirupsen/logrus"
"github.com/pkg/errors"
)
// config logrus log to amqp
func ConfigAmqpLogger(server, username, password, exchange, exchangeType, virtualHost, routingKey string) {
hook := logrus_amqp.NewAMQPHookWithType(server, username, password, exchange, exchangeType, virtualHost, routingKey)
log.AddHook(hook)
}
// config logrus log to es
func ConfigESLogger(esUrl string, esHOst string, index string) {
client, err := elastic.NewClient(elastic.SetURL(esUrl))
if err != nil {
log.Errorf("config es logger error. %+v", errors.WithStack(err))
}
esHook, err := elogrus.NewElasticHook(client, esHOst, log.DebugLevel, index)
if err != nil {
log.Errorf("config es logger error. %+v", errors.WithStack(err))
}
log.AddHook(esHook)
}