https://github.com/mattes/log

Uber Zap logger
https://github.com/mattes/log

go golang golang-logging log logging zap zap-core

Last synced: 4 months ago
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Uber Zap logger

• Host: GitHub
• URL: https://github.com/mattes/log
• Owner: mattes
• License: unlicense
• Created: 2019-11-07T01:25:58.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2023-03-06T22:37:34.000Z (almost 2 years ago)
• Last Synced: 2024-10-09T07:21:37.142Z (4 months ago)
• Topics: go, golang, golang-logging, log, logging, zap, zap-core
• Language: Go
• Homepage:
• Size: 3.64 MB
• Stars: 4
• Watchers: 2
• Forks: 0
• Open Issues: 4
• Metadata Files:
  • Readme: README.md

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README

        
# log [![GoDoc](https://godoc.org/github.com/mattes/log?status.svg)](https://godoc.org/github.com/mattes/log)

log acts as drop-in replacement for `std/log` and uses the power of

[Uber's Zap](https://github.com/uber-go/zap) logging library internally. 

It implements the following Zap cores:

  * [Google Cloud Error Reporting](/googleErrorReporting)

  * [Google Cloud Stackdriver Logging](/googleStackdriver)

  * [Slack](/slack)

  * [Prometheus](/prometheus)

## Usage

A __development__ setup is used by default. Similar to `std/log`.

All logs are written to stderr.

```go

import "github.com/mattes/log"

func main() {

  defer log.Sync()

  log.Info("Hello world")

}

```

In __production__ the setup depends on where you want to ship your logs to.

Here is an example that ships all logs to Google Stackdriver, as well

as Google Error Reporting.

```go

import (

  "go.uber.org/zap"

  "go.uber.org/zap/zapcore"

  "github.com/mattes/log"

  gerr "github.com/mattes/log/googleErrorReporting"

  gsdr "github.com/mattes/log/googleStackdriver"

)

func init() {

  cores := []zapcore.Core{}

  {

    // Stackdriver core

    c := gsdr.NewConfig()

    c.LogID = "my-service.v2"

    core, err := c.Build()

    cores = append(cores, core)

  }

  {

    // Error reporting core

    c := gerr.NewConfig()

    c.ServiceName = "my-service"

    c.ServiceVersion = "v2"

    core, err := c.Build()

    cores = append(cores, core)

  }

  // Build Zap logger with options

  logger := zap.New(zapcore.NewTee(cores...)).WithOptions(

    zap.AddCaller(),

    zap.AddCallerSkip(1),

    zap.AddStacktrace(zapcore.ErrorLevel),

    log.ErrorOutput("stderr"), // for internal errors

    log.Sampling(100, 100),

  )

  // Set global logger

  log.Use(logger)

}

func main() {

  defer log.Sync()

  defer log.CapturePanic() // optional, it logs unhandled panics before crashing

  log.Error("Hello Production!")

}

```

## Changing log level

Update the config to use a reference of [zap#AtomicLevel](https://godoc.org/go.uber.org/zap#NewAtomicLevel)

that you control. It can serve as [HTTP handler](https://godoc.org/go.uber.org/zap#AtomicLevel.ServeHTTP), too.

## Replacing logger in third-party lib

Sometimes third-party libraries log on their own with no way of disabling it.

With the help of Go modules we can replace third-party logging libraries 

and instruct them to log through our logging infrastructure.

  * [golang/glog](/glog)

## Testing

Some tests require credentials and configration that can't be commited to the repo.

I recommend putting a `.env` file in each directory with contents like:

```

export SLACK_URL='https://hooks.slack.com/services/xxx'

```

Then run test with `source .env && go test -v`