如何入门使用Go语言中的Zerolog日志库?

摘要:简介 Zerolog 是一个可以结构化输出 JSON 格式的 Go 日志库,其特点就是高性能,名字中的 zero 代表零分配设计,速度非常快。 什么是零分配设计? 在 Go 语言中,内存分配会带来一定的性能开销,频繁的内存分配和垃圾回收(G
简介 Zerolog 是一个可以结构化输出 JSON 格式的 Go 日志库,其特点就是高性能,名字中的 zero 代表零分配设计,速度非常快。 什么是零分配设计? 在 Go 语言中,内存分配会带来一定的性能开销,频繁的内存分配和垃圾回收(GC)会影响程序性能。零分配设计的目标是在热点代码路径上尽量避免堆内存分配,从而减少 GC 压力,提升整体性能。 Zerolog 通过精心设计的 API 实现了这一目标: 链式调用返回指针而非值:避免了每次调用都创建新的对象 使用 sync.Pool 复用对象:日志事件对象会被放回池中重复利用 避免接口类型:直接使用具体类型,消除接口调用的开销 预分配缓冲区:减少写入时的内存分配 这种设计使得 Zerolog 在高并发场景下表现出色,尤其适合对性能敏感的服务端应用。 有人做了一个 Go 日志库 benchmark: https://betterstack-community.github.io/go-logging-benchmarks/,可以看出 zerolog 相较于其它日志库,性能都是第一档的,不管是执行速度还是内存占用,表现得都非常好。 特点 高性能:零分配设计,极高的写入速度,对 GC 几乎无压力。 结构化日志:默认输出 JSON 格式,便于日志系统(如 ELK、Loki)解析和检索。 支持 context:可以在请求链路中传递和追加日志字段,实现请求级别的日志追踪。 日志采样:对高频日志进行采样,防止日志风暴撑爆磁盘。 Hook 机制:可在日志写入前进行拦截处理,例如发送错误日志到 Sentry。 彩色输出:开发环境下可以启用彩色输出,提升可读性。 安装 go get github.com/rs/zerolog/log 基本使用 Zerolog 开箱即用,无需复杂配置即可快速上手。默认输出到 stderr,日志格式为 JSON,每条日志自动包含 level 和 time 字段。 Zerolog 采用链式调用风格,API 设计简洁直观: log.Info()、log.Warn()、log.Error() 等方法创建对应级别的日志事件 Str()、Int()、Float64() 等方法添加自定义字段 Msg() 或 Msgf() 方法最终输出日志 package main import ( "errors" "github.com/rs/zerolog/log" ) func main() { log.Info().Msg("hello world") log.Warn().Str("key1", "value1").Float64("fnumber", 12.34).Msg("this is a message") err := errors.New("this is an error") log.Error().Err(err).Str("service", "user").Msgf("couldn't start %s", "user") } 运行输出: go run main.go {"level":"info","time":"2026-03-10T20:41:01+08:00","message":"hello world"} {"level":"warn","key1":"value1","fnumber":12.34,"time":"2026-03-10T20:41:01+08:00","message":"this is a message"} {"level":"error","error":"this is an error","service":"user","time":"2026-03-10T20:41:01+08:00","message":"couldn't start user"} 基本配置 可以进行一些基本配置: package main import ( "os" "time" "github.com/rs/zerolog" "github.com/rs/zerolog/log" ) func main() { // 全局设置:设置 time 字段值为 unix 时间戳 zerolog.TimeFieldFormat = zerolog.TimeFormatUnix // 全局设置:设置日志级别 zerolog.SetGlobalLevel(zerolog.DebugLevel) // 输出到 stdout。开发环境可以输出到 console 中,生产环境还是用默认的 JSON 比较好 log.Logger = log.Output(zerolog.ConsoleWriter{Out: os.Stdout, NoColor: true, TimeFormat: time.RFC3339}) // 基本日志 log.Info().Msg("hello world") // 链式调用:指定类型有助于性能 log.Warn().Str("key1", "value1").Float64("fnumber", 12.34).Msg("this is a message") } 执行输出: $ go run main.go 2026-03-10T21:00:31+08:00 INF hello world 2026-03-10T21:00:31+08:00 WRN this is a message fnumber=12.34 key1=value1 日志级别 Zerolog 支持以下日志级别,按严重程度从高到低排列: 级别 常量 值 说明 panic zerolog.PanicLevel 5 记录日志后调用 panic() fatal zerolog.FatalLevel 4 记录日志后调用 os.Exit(1) error zerolog.ErrorLevel 3 错误信息,不影响程序继续运行 warn zerolog.WarnLevel 2 警告信息,潜在问题提示 info zerolog.InfoLevel 1 一般信息,默认级别 debug zerolog.DebugLevel 0 调试信息,开发环境使用 trace zerolog.TraceLevel -1 最详细的追踪信息 使用建议: 生产环境建议设置为 InfoLevel 或 WarnLevel 开发环境可以设置为 DebugLevel 便于调试 panic 和 fatal 会中断程序,谨慎使用 添加调用者信息 package main import ( "os" "time" "github.com/rs/zerolog" ) func main() { zerolog.TimeFieldFormat = time.RFC3339 // 全局设置时间格式为 RFC3339 zerolog.TimestampFieldName = "timestamp" // 全局设置时间字段名为 timestamp zerolog.MessageFieldName = "msg" // 全局设置消息字段名为 msg zerolog.SetGlobalLevel(zerolog.InfoLevel) // 全局设置日志级别为 InfoLevel // 创建自定义日志记录器,添加时间戳、调用者信息 // Str("service", "backend") 可以在所有日志中添加服务名称 logger := zerolog.New(os.Stdout).With().Str("service", "backend").Timestamp().Caller().Logger() logger.Debug().Msg("this is a debug message. it will not be logged") logger.Info().Dict("metrics", zerolog.Dict().Str("remote_addr", "1.2.3.4").Int("status", 200)).Msg("this is a metric") } 执行输出: $ go run main.go | tail -n 1 | python3 -m json.tool { "level": "info", "service": "backend", "metrics": { "remote_addr": "1.2.3.4", "status": 200 }, "timestamp": "2026-03-10T22:33:39+08:00", "caller": "/home/rainux/Documents/workspace/go-dev/zerolog-exp/main.go:21", "msg": "this is a metric" } 采样 - Sampling 采样功能用于控制日志输出频率,防止瞬间日志风暴快速塞满硬盘。这在调试某些高频循环或处理突发流量时特别有用。 Zerolog 提供了多种采样器: // BasicSampler: 每 N 条日志只记录 1 条 log.Sample(&zerolog.BasicSampler{N: 100}).Info().Msg("High frequency log") // BurstSampler: 每秒最多记录 N 条,超过后按给定比例采样 // 下面示例:每秒最多 100 条,超出后只记录 10% log.Sample(&zerolog.BurstSampler{Burst: 100, Period: time.Second, NextSampler: &zerolog.BasicSampler{N: 10}}) 使用场景: 调试循环中的日志,避免日志爆炸 高并发接口的请求日志 限流降级时的日志记录 Context Zerolog 原生支持 Go 的 context.Context,非常适合在请求链路中传递日志字段。 工作原理: Logger.WithContext(ctx) 将 Logger 绑定到 context 中 zerolog.Ctx(ctx) 从 context 中取出 Logger 取出的 Logger 会携带之前设置的所有字段 这种方式特别适合 Web 服务,可以在中间件中设置 request_id、user_id 等字段,然后在后续处理函数中直接使用。 package main import ( "context" "github.com/rs/zerolog" "github.com/rs/zerolog/log" ) func someFunc(ctx context.Context) { logger := zerolog.Ctx(ctx) logger.Info().Msg("this is someFunc") } func main() { // 创建带 context 的 logger ctxLogger := log.With().Str("request_id", "1234qwer").Logger().WithContext(context.Background()) someFunc(ctxLogger) } 运行输出: $ go run main.go {"level":"info","request_id":"1234qwer","time":"2026-03-10T22:49:23+08:00","message":"this is someFunc"} Hook Hook 的作用是在日志写入前进行拦截处理,可以实现一些通用逻辑: 给所有日志添加通用字段(如服务名、环境、主机名) 根据日志级别做不同处理(如错误日志发送到监控系统) 过滤敏感信息 实现日志路由(不同级别输出到不同目标) 实现 Hook 只需定义一个结构体并实现 Run(e *zerolog.Event, level zerolog.Level, msg string) 方法。 package main import ( "context" "errors" "github.com/rs/zerolog" "github.com/rs/zerolog/log" ) func someFunc(ctx context.Context) { logger := zerolog.Ctx(ctx) logger.Info().Msg("this is someFunc") } type SentryHook struct{} func (h SentryHook) Run(e *zerolog.Event, level zerolog.Level, msg string) { if level != zerolog.NoLevel { e.Str("severity", level.String()) } if level == zerolog.ErrorLevel { // 错误日志发送到 sentry log.Info().Msgf("send to sentry: %s", msg) } } func main() { hooked := log.Hook(SentryHook{}) hooked.Warn().Msg("this is a WARN level message") hooked.Error().Msg("this is a ERROR level message") err := errors.New("Value error") hooked.Error().Err(err).Msg("some value is error") } 运行输出,可以看到 hook 中的逻辑会先执行: $ go run main.go {"level":"warn","time":"2026-03-10T23:20:17+08:00","severity":"warn","message":"this is a WARN level message"} {"level":"info","time":"2026-03-10T23:20:17+08:00","message":"send to sentry: this is a ERROR level message"} {"level":"error","time":"2026-03-10T23:20:17+08:00","severity":"error","message":"this is a ERROR level message"} {"level":"info","time":"2026-03-10T23:20:17+08:00","message":"send to sentry: some value is error"} {"level":"error","error":"Value error","time":"2026-03-10T23:20:17+08:00","severity":"error","message":"some value is error"} 同时输出控制台和日志文件 + 自动轮转 在传统服务器上部署时,同时输出到控制台和日志文件是一个常见需求,并且还需要自动轮转以控制日志文件体积,防止日志撑爆硬盘资源。 如果服务部署在 Kubernetes 或 Docker 环境,有完善的日志监控系统可以采集控制台日志,可以直接去掉输出日志文件的功能。 package main import ( "os" "time" "github.com/rs/zerolog" "gopkg.in/natefinch/lumberjack.v2" ) func main() { consoleWriter := zerolog.ConsoleWriter{ Out: os.Stdout, NoColor: false, // 输出颜色 TimeFormat: time.RFC3339, // 设置时间格式 PartsOrder: []string{"time", "level", "message"}, // 设置字段排列顺序 } // 日志文件配置 lumberjackLogger := &lumberjack.Logger{ Filename: "logs/app.log", // 日志文件路径,lumberjack 会自动创建 logs 目录 MaxSize: 100, // 单个文件最大大小 (MB) MaxBackups: 5, // 保留的旧文件最大数量 MaxAge: 30, // 文件最大保留时间 (天) Compress: true, // 是否压缩旧日志 (gzip) LocalTime: true, // 使用本地时间命名备份文件 } multiwriter := zerolog.MultiLevelWriter(consoleWriter, lumberjackLogger) logger := zerolog.New(multiwriter).With().Timestamp().Logger() logger.Info().Msg("Hello, World!") logger.Info().Dict("metrics", zerolog.Dict().Float64("cpupercent", 51.23).Int("memoryusage", 11)).Msg("this is a metric") } 执行输出: $ go run main.go 2026-03-10T21:23:33+08:00 INF Hello, World! 2026-03-10T21:23:33+08:00 INF this is a metric metrics={"cpupercent":51.23,"memoryusage":11} $ tail logs/app.log {"level":"info","time":"2026-03-10T21:23:33+08:00","message":"Hello, World!"} {"level":"info","metrics":{"cpupercent":51.23,"memoryusage":11},"time":"2026-03-10T21:23:33+08:00","message":"this is a metric"} 在 Gin 中集成 zerolog 替代 Gin 默认的 logger 和 recovery 中间件: package main import ( "context" "net" "net/http" "net/http/httputil" "os" "runtime/debug" "strings" "time" "github.com/gin-gonic/gin" "github.com/google/uuid" "github.com/rs/zerolog" "github.com/rs/zerolog/log" ) const ( TRACING_KEY = "traceId" ) type TracingHook struct{} func (h TracingHook) Run(e *zerolog.Event, level zerolog.Level, msg string) { ctx := e.GetCtx() if ctx != nil { if traceId, ok := ctx.Value(TRACING_KEY).(string); ok && traceId != "" { e.Str(TRACING_KEY, traceId) } } } func ZeroLogMiddleware() gin.HandlerFunc { return func(c *gin.Context) { start := time.Now() traceID := c.GetHeader("X-Trace-ID") if traceID == "" { traceID = uuid.New().String() } ctx := context.WithValue(c.Request.Context(), TRACING_KEY, traceID) c.Request = c.Request.WithContext(ctx) c.Header("X-Trace-ID", traceID) c.Next() log.Info().Ctx(ctx). Str("method", c.Request.Method). Str("path", c.Request.URL.Path). Str("remote_addr", c.Request.RemoteAddr). Int("status", c.Writer.Status()). Int("response_size", c.Writer.Size()).Dur("latency", time.Since(start)).Msg("") } } func ZeroLogRecovery() gin.HandlerFunc { return func(c *gin.Context) { defer func() { if err := recover(); err != nil { // 检查是否是连接中断(broken pipe) var brokenPipe bool if ne, ok := err.(*net.OpError); ok { if se, ok := ne.Err.(*os.SyscallError); ok { if strings.Contains(strings.ToLower(se.Error()), "broken pipe") || strings.Contains(strings.ToLower(se.Error()), "connection reset by peer") { brokenPipe = true } } } // 获取堆栈信息 stack := string(debug.Stack()) // 获取原始请求内容 httpRequest, _ := httputil.DumpRequest(c.Request, false) ctx := c.Request.Context() if brokenPipe { log.Error().Ctx(ctx).Any("error", err).Str("request", string(httpRequest)).Msg("network connection broken") c.Abort() return } log.Error().Ctx(ctx).Any("error", err).Str("stack", stack).Str("request", string(httpRequest)).Msg("recovery from panic") traceID, _ := ctx.Value(TRACING_KEY).(string) c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{ "code": http.StatusInternalServerError, "msg": "Internal Server Error", "data": nil, "timestamp": time.Now().Format(time.RFC3339), "trace_id": traceID, }) } }() c.Next() } } func main() { zerolog.TimeFieldFormat = time.RFC3339 logger := zerolog.New(os.Stdout).With().Timestamp().Caller().Logger() logger = logger.Hook(TracingHook{}) log.Logger = logger r := gin.New() r.Use(ZeroLogMiddleware()) r.Use(ZeroLogRecovery()) r.GET("/ping", func(c *gin.Context) { log.Info().Ctx(c.Request.Context()).Msg("get a ping request") time.Sleep(2 * time.Second) c.String(200, "pong") }) r.GET("/panic", func(c *gin.Context) { log.Info().Ctx(c.Request.Context()).Msg("get a panic request") panic("something went wrong") }) r.Run("127.0.0.1:10000") } 请求测试,可以看到响应头中已经包含了 TraceID: $ curl http://127.0.0.1:10000/ping -v * Trying 127.0.0.1:10000... * Connected to 127.0.0.1 (127.0.0.1) port 10000 * using HTTP/1.x > GET /ping HTTP/1.1 > Host: 127.0.0.1:10000 > User-Agent: curl/8.14.1 > Accept: */* > * Request completely sent off < HTTP/1.1 200 OK < Content-Type: text/plain; charset=utf-8 < X-Trace-Id: 22c92423-2e95-4ded-934f-f0fd51f36cc7 < Date: Tue, 10 Mar 2026 16:13:40 GMT < Content-Length: 4 < * Connection #0 to host 127.0.0.1 left intact pong 在服务端日志中也能看到对应的日志记录: {"level":"info","time":"2026-03-11T00:13:38+08:00","caller":"/home/rainux/Documents/workspace/go-dev/zerolog-exp/main.go:63","traceId":"22c92423-2e95-4ded-934f-f0fd51f36cc7","message":"get a ping request"} {"level":"info","method":"GET","path":"/ping","remote_addr":"127.0.0.1:56540","status":200,"response_size":4,"latency":2001.158295,"time":"2026-03-11T00:13:40+08:00"} 再试试异常恢复功能: $ curl http://127.0.0.1:10000/panic -v * Trying 127.0.0.1:10000... * Connected to 127.0.0.1 (127.0.0.1) port 10000 * using HTTP/1.x > GET /panic HTTP/1.1 > Host: 127.0.0.1:10000 > User-Agent: curl/8.14.1 > Accept: */* > * Request completely sent off < HTTP/1.1 500 Internal Server Error < Content-Type: application/json; charset=utf-8 < X-Trace-Id: 384ddafe-2434-433f-8fa4-883fda1580f3 < Date: Tue, 10 Mar 2026 16:34:44 GMT < Content-Length: 144 < * Connection #0 to host 127.0.0.1 left intact {"code":500,"data":null,"msg":"Internal Server Error","timestamp":"2026-03-11T00:34:44+08:00","trace_id":"384ddafe-2434-433f-8fa4-883fda1580f3"} 在服务端也能观察到相应的报错堆栈信息: {"level":"error","error":"something went wrong","stack":"goroutine 8 [running]:\nruntime/debug.Stack()\n\truntime/debug/stack.go:26 +0x5e\nmain.main.ZeroLogRecovery.func4.1()\n\tzerolog-exp/main.go:71 +0x105\npanic({0xb26900?, 0xc24a00?})\n\truntime/panic.go:860 +0x13a\nmain.main.func2(0x33b8c231a500)\n\tzerolog-exp/main.go:121 +0x7a\ngithub.com/gin-gonic/gin.(*Context).Next(0x33b8c231a500)\n\tgithub.com/gin-gonic/gin@v1.12.0/context.go:192 +0x5f\nmain.main.ZeroLogRecovery.func4(0x33b8c250ac00?)\n\tzerolog-exp/main.go:97 +0x3f\ngithub.com/gin-gonic/gin.(*Context).Next(0x33b8c231a500)\n\tgithub.com/gin-gonic/gin@v1.12.0/context.go:192 +0x5f\nmain.main.ZeroLogMiddleware.func3(0x33b8c231a500)\n\tzerolog-exp/main.go:46 +0x154\ngithub.com/gin-gonic/gin.(*Context).Next(0x33b8c231a500)\n\tgithub.com/gin-gonic/gin@v1.12.0/context.go:192 +0x5f\ngithub.com/gin-gonic/gin.(*Engine).handleHTTPRequest(0x33b8c2506380, 0x33b8c231a500)\n\tgithub.com/gin-gonic/gin@v1.12.0/gin.go:722 +0x45e\ngithub.com/gin-gonic/gin.(*Engine).ServeHTTP(0x33b8c2506380, {0xc2ba38, 0x33b8c252c000}, 0x33b8c2502500)\n\tgithub.com/gin-gonic/gin@v1.12.0/gin.go:672 +0x1dc\nnet/http.serverHandler.ServeHTTP({0x33b8c23f5dc0?}, {0xc2ba38?, 0x33b8c252c000?}, 0x1?)\n\tnet/http/server.go:3311 +0x8e\nnet/http.(*conn).serve(0x33b8c24ae5a0, {0xc2c0f0, 0x33b8c250aa20})\n\tnet/http/server.go:2073 +0x650\ncreated by net/http.(*Server).Serve in goroutine 1\n\tnet/http/server.go:3464 +0x485\n","request":"GET /panic HTTP/1.1\r\nHost: 127.0.0.1:10000\r\nAccept: */*\r\nUser-Agent: curl/8.14.1\r\n\r\n","time":"2026-03-11T00:34:44+08:00","caller":"zerolog-exp/main.go:83","traceId":"384ddafe-2434-433f-8fa4-883fda1580f3","message":"recovery from panic"} {"level":"info","method":"GET","path":"/panic","remote_addr":"127.0.0.1:42380","status":500,"response_size":144,"latency":0.184455,"time":"2026-03-11T00:34:44+08:00","caller":"zerolog-exp/main.go:52","traceId":"384ddafe-2434-433f-8fa4-883fda1580f3"}