zerolog README

The project's README from github.com/rs/zerolog. As one markdown file: README.md.

Zero Allocation JSON Logger

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The zerolog package provides a fast and simple logger dedicated to JSON output.

Zerolog's API is designed to provide both a great developer experience and stunning performance. Its unique chaining API allows zerolog to write JSON (or CBOR) log events by avoiding allocations and reflection.

Uber's zap library pioneered this approach. Zerolog is taking this concept to the next level with a simpler to use API and even better performance.

To keep the code base and the API simple, zerolog focuses on efficient structured logging only. Pretty logging on the console is made possible using the provided (but inefficient) zerolog.ConsoleWriter.

Pretty Logging Image

Who uses zerolog

Find out who uses zerolog and add your company / project to the list.

Features

Installation

go get -u github.com/rs/zerolog/log

Getting Started

Simple Logging Example

For simple logging, import the global logger package github.com/rs/zerolog/log

package main

import (
    "github.com/rs/zerolog"
    "github.com/rs/zerolog/log"
)

func main() {
    // UNIX Time is faster and smaller than most timestamps
    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix

    log.Print("hello world")
}

// Output: {"time":1516134303,"level":"debug","message":"hello world"}

Note: By default log writes to os.Stderr Note: The default log level for log.Print is trace

Contextual Logging

zerolog allows data to be added to log messages in the form of key:value pairs. The data added to the message adds "context" about the log event that can be critical for debugging as well as myriad other purposes. An example of this is below:

package main

import (
    "github.com/rs/zerolog"
    "github.com/rs/zerolog/log"
)

func main() {
    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix

    log.Debug().
        Str("Scale", "833 cents").
        Float64("Interval", 833.09).
        Msg("Fibonacci is everywhere")

    log.Debug().
        Str("Name", "Tom").
        Send()
}

// Output: {"level":"debug","Scale":"833 cents","Interval":833.09,"time":1562212768,"message":"Fibonacci is everywhere"}
// Output: {"level":"debug","Name":"Tom","time":1562212768}

You'll note in the above example that when adding contextual fields, the fields are strongly typed. You can find the full list of supported fields here

Leveled Logging

Simple Leveled Logging Example

package main

import (
    "github.com/rs/zerolog"
    "github.com/rs/zerolog/log"
)

func main() {
    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix

    log.Info().Msg("hello world")
}

// Output: {"time":1516134303,"level":"info","message":"hello world"}

It is very important to note that when using the zerolog chaining API, as shown above (log.Info().Msg("hello world"), the chain must have either the Msg or Msgf method call. If you forget to add either of these, the log will not occur and there is no compile time error to alert you of this.

zerolog allows for logging at the following levels (from highest to lowest):

You can set the Global logging level to any of these options using the SetGlobalLevel function in the zerolog package, passing in one of the given constants above, e.g. zerolog.InfoLevel would be the "info" level. Whichever level is chosen, all logs with a level greater than or equal to that level will be written. To turn off logging entirely, pass the zerolog.Disabled constant.

Default level. If you never call SetGlobalLevel, the global logger writes to os.Stderr at the trace level (the lowest level), so every event - trace, debug, info, warn, error, fatal, panic - is written to stderr by default. In particular, a plain log.Info(...) call will appear on stderr out of the box. Calling zerolog.SetGlobalLevel(zerolog.InfoLevel) raises the minimum level so trace and debug messages are suppressed.

Setting Global Log Level

This example uses command-line flags to demonstrate various outputs depending on the chosen log level.

package main

import (
    "flag"

    "github.com/rs/zerolog"
    "github.com/rs/zerolog/log"
)

func main() {
    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix
    debug := flag.Bool("debug", false, "sets log level to debug")

    flag.Parse()

    // Default level for this example is info, unless debug flag is present
    zerolog.SetGlobalLevel(zerolog.InfoLevel)
    if *debug {
        zerolog.SetGlobalLevel(zerolog.DebugLevel)
    }

    log.Debug().Msg("This message appears only when log level set to Debug")
    log.Info().Msg("This message appears when log level set to Debug or Info")

    if e := log.Debug(); e.Enabled() {
        // Compute log output only if enabled.
        value := "bar"
        e.Str("foo", value).Msg("some debug message")
    }
}

Info Output (no flag)

$ ./logLevelExample
{"time":1516387492,"level":"info","message":"This message appears when log level set to Debug or Info"}

Debug Output (debug flag set)

$ ./logLevelExample -debug
{"time":1516387573,"level":"debug","message":"This message appears only when log level set to Debug"}
{"time":1516387573,"level":"info","message":"This message appears when log level set to Debug or Info"}
{"time":1516387573,"level":"debug","foo":"bar","message":"some debug message"}

Logging without Level or Message

You may choose to log without a specific level by using the Log method. You may also write without a message by setting an empty string in the msg string parameter of the Msg method. Both are demonstrated in the example below.

package main

import (
    "github.com/rs/zerolog"
    "github.com/rs/zerolog/log"
)

func main() {
    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix

    log.Log().
        Str("foo", "bar").
        Msg("")
}

// Output: {"time":1494567715,"foo":"bar"}

Error Logging

You can log errors using the Err method

package main

import (
    "errors"

    "github.com/rs/zerolog"
    "github.com/rs/zerolog/log"
)

func main() {
    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix

    err := errors.New("seems we have an error here")
    log.Error().Err(err).Msg("")
}

// Output: {"level":"error","error":"seems we have an error here","time":1609085256}

The default field name for errors is error, you can change this by setting zerolog.ErrorFieldName to meet your needs.

Error Logging with Stacktrace

Using github.com/pkg/errors, you can add a formatted stacktrace to your errors.

package main

import (
    "github.com/pkg/errors"
    "github.com/rs/zerolog/pkgerrors"

    "github.com/rs/zerolog"
    "github.com/rs/zerolog/log"
)

func main() {
    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix
    zerolog.ErrorStackMarshaler = pkgerrors.MarshalStack

    err := outer()
    log.Error().Stack().Err(err).Msg("")
}

func inner() error {
    return errors.New("seems we have an error here")
}

func middle() error {
    err := inner()
    if err != nil {
        return err
    }
    return nil
}

func outer() error {
    err := middle()
    if err != nil {
        return err
    }
    return nil
}

// Output: {"level":"error","stack":[{"func":"inner","line":"20","source":"errors.go"},{"func":"middle","line":"24","source":"errors.go"},{"func":"outer","line":"32","source":"errors.go"},{"func":"main","line":"15","source":"errors.go"},{"func":"main","line":"204","source":"proc.go"},{"func":"goexit","line":"1374","source":"asm_amd64.s"}],"error":"seems we have an error here","time":1609086683}

zerolog.ErrorStackMarshaler must be set in order for the stack to output anything.

Logging Fatal Messages

package main

import (
    "errors"

    "github.com/rs/zerolog"
    "github.com/rs/zerolog/log"
)

func main() {
    err := errors.New("A repo man spends his life getting into tense situations")
    service := "myservice"

    zerolog.TimeFieldFormat = zerolog.TimeFormatUnix

    log.Fatal().
        Err(err).
        Str("service", service).
        Msgf("Cannot start %s", service)
}

// Output: {"time":1516133263,"level":"fatal","error":"A repo man spends his life getting into tense situations","service":"myservice","message":"Cannot start myservice"}
//         exit status 1

NOTE: Using Msgf generates one allocation even when the logger is disabled.

Create logger instance to manage different outputs

logger := zerolog.New(os.Stderr).With().Timestamp().Logger()

logger.Info().Str("foo", "bar").Msg("hello world")

// Output: {"level":"info","time":1494567715,"message":"hello world","foo":"bar"}

Sub-loggers let you chain loggers with additional context

sublogger := log.With().
                 Str("component", "foo").
                 Logger()
sublogger.Info().Msg("hello world")

// Output: {"level":"info","time":1494567715,"message":"hello world","component":"foo"}

Pretty logging

To log a human-friendly, colorized output, use zerolog.ConsoleWriter:

log.Logger = log.Output(zerolog.ConsoleWriter{Out: os.Stderr})

log.Info().Str("foo", "bar").Msg("Hello world")

// Output: 3:04PM INF Hello World foo=bar

To customize the configuration and formatting:

output := zerolog.ConsoleWriter{Out: os.Stdout, TimeFormat: time.RFC3339}
output.FormatLevel = func(i interface{}) string {
    return strings.ToUpper(fmt.Sprintf("| %-6s|", i))
}
output.FormatMessage = func(i interface{}) string {
    return fmt.Sprintf("***%s****", i)
}
output.FormatFieldName = func(i interface{}) string {
    return fmt.Sprintf("%s:", i)
}
output.FormatFieldValue = func(i interface{}) string {
    return strings.ToUpper(fmt.Sprintf("%s", i))
}

log := zerolog.New(output).With().Timestamp().Logger()

log.Info().Str("foo", "bar").Msg("Hello World")

// Output: 2006-01-02T15:04:05Z07:00 | INFO  | ***Hello World**** foo:BAR

To use custom advanced formatting:

output := zerolog.ConsoleWriter{Out: os.Stdout, NoColor: true,
    PartsOrder:    []string{"level", "one", "two", "three", "message"},
    FieldsExclude: []string{"one", "two", "three"}}
output.FormatLevel = func(i interface{}) string { return strings.ToUpper(fmt.Sprintf("%-6s", i)) }
output.FormatFieldName = func(i interface{}) string { return fmt.Sprintf("%s:", i) }
output.FormatPartValueByName = func(i interface{}, s string) string {
    var ret string
    switch s {
    case "one":
        ret = strings.ToUpper(fmt.Sprintf("%s", i))
    case "two":
        ret = strings.ToLower(fmt.Sprintf("%s", i))
    case "three":
        ret = strings.ToLower(fmt.Sprintf("(%s)", i))
    }
    return ret
}
log := zerolog.New(output)

log.Info().Str("foo", "bar").
    Str("two", "TEST_TWO").
    Str("one", "test_one").
    Str("three", "test_three").
    Msg("Hello World")

// Output: INFO   TEST_ONE test_two (test_three) Hello World foo:bar

Sub dictionary

log.Info().
    Str("foo", "bar").
    Dict("dict", zerolog.Dict().
        Str("bar", "baz").
        Int("n", 1),
    ).Msg("hello world")

// Output: {"level":"info","time":1494567715,"foo":"bar","dict":{"bar":"baz","n":1},"message":"hello world"}

Customize automatic field names

zerolog.TimestampFieldName = "t"
zerolog.LevelFieldName = "l"
zerolog.MessageFieldName = "m"

log.Info().Msg("hello world")

// Output: {"l":"info","t":1494567715,"m":"hello world"}

Add contextual fields to the global logger

log.Logger = log.With().Str("foo", "bar").Logger()

Add file and line number to log

Equivalent of Llongfile:

log.Logger = log.With().Caller().Logger()
log.Info().Msg("hello world")

// Output: {"level": "info", "message": "hello world", "caller": "/go/src/your_project/some_file:21"}

Equivalent of Lshortfile:

zerolog.CallerMarshalFunc = func(pc uintptr, file string, line int) string {
    return filepath.Base(file) + ":" + strconv.Itoa(line)
}
log.Logger = log.With().Caller().Logger()
log.Info().Msg("hello world")

// Output: {"level": "info", "message": "hello world", "caller": "some_file:21"}

Thread-safe, lock-free, non-blocking writer

If your writer might be slow or not thread-safe and you need your log producers to never get slowed down by a slow writer, you can use a diode.Writer as follows:

wr := diode.NewWriter(os.Stdout, 1000, 10*time.Millisecond, func(missed int) {
        fmt.Printf("Logger Dropped %d messages", missed)
    })
log := zerolog.New(wr)
log.Print("test")

You will need to install code.cloudfoundry.org/go-diodes to use this feature.

Log Sampling

sampled := log.Sample(&zerolog.BasicSampler{N: 10})
sampled.Info().Msg("will be logged every 10 messages")

// Output: {"time":1494567715,"level":"info","message":"will be logged every 10 messages"}

More advanced sampling:

// Will let 5 debug messages per period of 1 second.
// Over 5 debug message, 1 every 100 debug messages are logged.
// Other levels are not sampled.
sampled := log.Sample(zerolog.LevelSampler{
    DebugSampler: &zerolog.BurstSampler{
        Burst: 5,
        Period: 1*time.Second,
        NextSampler: &zerolog.BasicSampler{N: 100},
    },
})
sampled.Debug().Msg("hello world")

// Output: {"time":1494567715,"level":"debug","message":"hello world"}

Hooks

type SeverityHook struct{}

func (h SeverityHook) Run(e *zerolog.Event, level zerolog.Level, msg string) {
    if level != zerolog.NoLevel {
        e.Str("severity", level.String())
    }
}

hooked := log.Hook(SeverityHook{})
hooked.Warn().Msg("")

// Output: {"level":"warn","severity":"warn"}

Pass a sub-logger by context

ctx := log.With().Str("component", "module").Logger().WithContext(ctx)

log.Ctx(ctx).Info().Msg("hello world")

// Output: {"component":"module","level":"info","message":"hello world"}

Set as standard logger output

log := zerolog.New(os.Stdout).With().
    Str("foo", "bar").
    Logger()

stdlog.SetFlags(0)
stdlog.SetOutput(log)

stdlog.Print("hello world")

// Output: {"foo":"bar","message":"hello world"}

context.Context integration

Go contexts are commonly passed throughout Go code, and this can help you pass your Logger into places it might otherwise be hard to inject. The Logger instance may be attached to Go context (context.Context) using Logger.WithContext(ctx) and extracted from it using zerolog.Ctx(ctx). For example:

func f() {
    logger := zerolog.New(os.Stdout)
    ctx := context.Background()

    // Attach the Logger to the context.Context
    ctx = logger.WithContext(ctx)
    someFunc(ctx)
}

func someFunc(ctx context.Context) {
    // Get Logger from the go Context. if it's nil, then
    // `zerolog.DefaultContextLogger` is returned, if
    // `DefaultContextLogger` is nil, then a disabled logger is returned.
    logger := zerolog.Ctx(ctx)
    logger.Info().Msg("Hello")
}

A second form of context.Context integration allows you to pass the current context.Context into the logged event, and retrieve it from hooks. This can be useful to log trace and span IDs or other information stored in the go context, and facilitates the unification of logging and tracing in some systems:

type TracingHook struct{}

func (h TracingHook) Run(e *zerolog.Event, level zerolog.Level, msg string) {
    ctx := e.GetCtx()
    spanId := getSpanIdFromContext(ctx) // as per your tracing framework
    e.Str("span-id", spanId)
}

func f() {
    // Setup the logger
    logger := zerolog.New(os.Stdout)
    logger = logger.Hook(TracingHook{})

    ctx := context.Background()
    // Use the Ctx function to make the context available to the hook
    logger.Info().Ctx(ctx).Msg("Hello")
}

Integration with net/http

The github.com/rs/zerolog/hlog package provides some helpers to integrate zerolog with http.Handler.

In this example we use alice to install logger for better readability.

log := zerolog.New(os.Stdout).With().
    Timestamp().
    Str("role", "my-service").
    Str("host", host).
    Logger()

c := alice.New()

// Install the logger handler with default output on the console
c = c.Append(hlog.NewHandler(log))

// Install some provided extra handler to set some request's context fields.
// Thanks to that handler, all our logs will come with some prepopulated fields.
c = c.Append(hlog.AccessHandler(func(r *http.Request, status, size int, duration time.Duration) {
    hlog.FromRequest(r).Info().
        Str("method", r.Method).
        Stringer("url", r.URL).
        Int("status", status).
        Int("size", size).
        Dur("duration", duration).
        Msg("")
}))
c = c.Append(hlog.RemoteAddrHandler("ip"))
c = c.Append(hlog.UserAgentHandler("user_agent"))
c = c.Append(hlog.RefererHandler("referer"))
c = c.Append(hlog.RequestIDHandler("req_id", "Request-Id"))

// Here is your final handler
h := c.Then(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    // Get the logger from the request's context. You can safely assume it
    // will be always there: if the handler is removed, hlog.FromRequest
    // will return a no-op logger.
    hlog.FromRequest(r).Info().
        Str("user", "current user").
        Str("status", "ok").
        Msg("Something happened")

    // Output: {"level":"info","time":"2001-02-03T04:05:06Z","role":"my-service","host":"local-hostname","req_id":"b4g0l5t6tfid6dtrapu0","user":"current user","status":"ok","message":"Something happened"}
}))
http.Handle("/", h)

if err := http.ListenAndServe(":8080", nil); err != nil {
    log.Fatal().Err(err).Msg("Startup failed")
}

Multiple Log Output

zerolog.MultiLevelWriter may be used to send the log message to multiple outputs.

In this example, we send the log message to both os.Stdout and the in-built ConsoleWriter.

func main() {
    consoleWriter := zerolog.ConsoleWriter{Out: os.Stdout}
    multi := zerolog.MultiLevelWriter(consoleWriter, os.Stdout)
    logger := zerolog.New(multi).With().Timestamp().Logger()
    logger.Info().Msg("Hello World!")
}

// Output (Line 1: Console; Line 2: Stdout)
// 12:36PM INF Hello World!
// {"level":"info","time":"2019-11-07T12:36:38+03:00","message":"Hello World!"}

Global Settings

Some settings can be changed and will be applied to all loggers:

Field Types

Standard Types

Advanced Fields

Most fields are also available in the slice format (Strs for []string, Errs for []error etc.)

Binary Encoding

In addition to the default JSON encoding, zerolog can produce binary logs using CBOR encoding. The choice of encoding can be decided at compile time using the build tag binary_log as follows:

go build -tags binary_log .

To decode binary encoded log files you can use any CBOR decoder. One has been tested to work with zerolog library is CSD.

Integration with log/slog

zerolog provides a slog.Handler implementation that routes log/slog records through a zerolog logger. This lets you use the standard library's slog API while keeping zerolog's performance and encoding:

package main

import (
    "log/slog"

    "github.com/rs/zerolog"
    "github.com/rs/zerolog/log"
)

func main() {
    zl := log.Logger
    handler := zerolog.NewSlogHandler(zl)
    logger := slog.New(handler)

    logger.Info("user logged in", "user", "alice", "role", "admin")
}

// Output: {"level":"info","user":"alice","role":"admin","time":"...","message":"user logged in"}

The handler supports all slog features including WithAttrs, WithGroup, nested groups, and LogValuer resolution. slog levels are mapped to zerolog levels (e.g. slog.LevelDebug to zerolog.DebugLevel).

Benchmarks

See logbench for more comprehensive and up-to-date benchmarks.

All operations are allocation free (those numbers include JSON encoding):

BenchmarkLogEmpty-8        100000000    19.1 ns/op     0 B/op       0 allocs/op
BenchmarkDisabled-8        500000000    4.07 ns/op     0 B/op       0 allocs/op
BenchmarkInfo-8            30000000     42.5 ns/op     0 B/op       0 allocs/op
BenchmarkContextFields-8   30000000     44.9 ns/op     0 B/op       0 allocs/op
BenchmarkLogFields-8       10000000     184 ns/op      0 B/op       0 allocs/op

There are a few Go logging benchmarks and comparisons that include zerolog.

Using Uber's zap comparison benchmark:

Log a message and 10 fields:

Library Time Bytes Allocated Objects Allocated
zerolog 767 ns/op 552 B/op 6 allocs/op
:zap: zap 848 ns/op 704 B/op 2 allocs/op
:zap: zap (sugared) 1363 ns/op 1610 B/op 20 allocs/op
go-kit 3614 ns/op 2895 B/op 66 allocs/op
lion 5392 ns/op 5807 B/op 63 allocs/op
logrus 5661 ns/op 6092 B/op 78 allocs/op
apex/log 15332 ns/op 3832 B/op 65 allocs/op
log15 20657 ns/op 5632 B/op 93 allocs/op

Log a message with a logger that already has 10 fields of context:

Library Time Bytes Allocated Objects Allocated
zerolog 52 ns/op 0 B/op 0 allocs/op
:zap: zap 283 ns/op 0 B/op 0 allocs/op
:zap: zap (sugared) 337 ns/op 80 B/op 2 allocs/op
lion 2702 ns/op 4074 B/op 38 allocs/op
go-kit 3378 ns/op 3046 B/op 52 allocs/op
logrus 4309 ns/op 4564 B/op 63 allocs/op
apex/log 13456 ns/op 2898 B/op 51 allocs/op
log15 14179 ns/op 2642 B/op 44 allocs/op

Log a static string, without any context or printf-style templating:

Library Time Bytes Allocated Objects Allocated
zerolog 50 ns/op 0 B/op 0 allocs/op
:zap: zap 236 ns/op 0 B/op 0 allocs/op
standard library 453 ns/op 80 B/op 2 allocs/op
:zap: zap (sugared) 337 ns/op 80 B/op 2 allocs/op
go-kit 508 ns/op 656 B/op 13 allocs/op
lion 771 ns/op 1224 B/op 10 allocs/op
logrus 1244 ns/op 1505 B/op 27 allocs/op
apex/log 2751 ns/op 584 B/op 11 allocs/op
log15 5181 ns/op 1592 B/op 26 allocs/op

Caveats

Field duplication

Note that zerolog does no de-duplication of fields. Using the same key multiple times creates multiple keys in final JSON:

logger := zerolog.New(os.Stderr).With().Timestamp().Logger()
logger.Info().
       Timestamp().
       Msg("dup")
// Output: {"level":"info","time":1494567715,"time":1494567715,"message":"dup"}

In this case, many consumers will take the last value, but this is not guaranteed; check yours if in doubt.

Concurrency safety

Be careful when calling UpdateContext. It is not concurrency safe. Use the With() method to create a child logger:

func handler(w http.ResponseWriter, r *http.Request) {
    // Create a child logger for concurrency safety
    logger := log.Logger.With().Logger()

    // Add context fields, for example User-Agent from HTTP headers
    logger.UpdateContext(func(c zerolog.Context) zerolog.Context {
        ...
    })
}

The Event object returned from the Logger level-specific message functions (e.g. Log(), Trace(), Debug(), etc.) is allocated in sync.Pool memory that will be returned to the pool as soon as the Msg(), Msgf(), Send(), or MsgFunc() writes the message and must not be accessed afterwards.

Do not hold a reference to the *Event while in callback functions or your own code. This is especially important in Hook.Run() and HookFunc functions or MarshalZerologObject(e *Event) callback (e.g. LogObjectMarshaler implementations).

Any Array objects returned from Context.CreateArray() or Event.CreateArray() are from a sync.Pool so do not hold references to them from within any MarshalZerologArray(a *Array) callback (e.g. LogArrayMarshaler implementations) or your own code as they will be cleared and returned to the pool after being buffered by a call to Context.Array() or Event.Array().

Any dictionary Event returned from Context.CreateDict() or Event.CreateDict() must not be referenced after being buffered by a call to Array.Dict(), Context.Dict(), or Event.Dict() as they will be cleared and returned to the pool.

zerolog (rs/zerolog)

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Zerolog
这是什么？Zerolog 是一个 Go 日志库，它以结构化的 JSON（或 CBOR）格式写入日志事件，内存分配次数为零或接近零，并采用链式 API 而不是反射。
它是独立的命令行工具，还是我可以导入到 Go 代码中的库？它是一个 Go 库，通过 'github.com/rs/zerolog' 导入（全局日志器位于 'github.com/rs/zerolog/log'）；它没有独立的可执行程序或命令行工具。
怎么把它加到项目里？如果想用简单的全局日志器，就导入 'github.com/rs/zerolog/log'；如果想更灵活地控制输出，可以自己创建 zerolog.Logger 实例。
要使用美化的控制台输出或无锁写入器，还需要额外设置吗？控制台输出除了使用内置的 zerolog.ConsoleWriter 外，无需额外设置；如果在输出较慢时想使用非阻塞写入器，还需要另外安装可选的 'code.cloudfoundry.org/go-diodes' 包。
使用链式 API 时有哪些需要注意的坑？如果在链式日志调用末尾忘记调用 .Msg() 或 .Msgf()，日志事件会被悄悄丢弃，且不会有编译时错误；另外，默认情况下，全局日志器会把包括 trace 级别在内的所有日志输出到 stderr，直到你把级别调高为止。
在基准测试中，zerolog 和 Uber 的 zap 相比表现如何？在 zap 自带的基准测试中，记录一条带 10 个上下文字段的消息时，zerolog 耗时 52 ns/op 且零内存分配，而 zap 为 283 ns/op；记录静态字符串时，zerolog 为 50 ns/op，zap 为 236 ns/op。
开发时能看到带颜色、便于阅读的日志吗？可以，zerolog.ConsoleWriter 能为开发场景输出带颜色、排版美观的控制台日志，不过官方说明它的效率低于默认的 JSON 编码。
它能和 Go 标准库的 log/slog 包集成吗？可以，zerolog 提供了一个 slog.Handler 实现，可以把 log/slog 的记录交给 zerolog 处理，并支持 WithAttrs、WithGroup、嵌套分组以及 LogValuer 解析。
我能通过 context.Context 传递日志器，或者和 net/http 集成吗？可以，Logger.WithContext(ctx) 和 zerolog.Ctx(ctx) 可以把日志器存入或取出 Go 的 context；'github.com/rs/zerolog/hlog' 包则提供了与 http.Handler 集成的辅助函数。
What are similar projects?telegraf, zap, logrus, ipatool, gjson, cobra, gf, sofka
Which topics is it in?golang-library, logging, observability, json, golang, performance, go, terminal, server, library, cli, cross-platform
Creator
rs
Size
1.4 MB
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12.5K
Updated
CommitOct 14
Age
9y
Commits · 90 Days