README
¶
log 
log acts as drop-in replacement for std/log and uses the power of
Uber's Zap logging library internally.
It implements the following Zap cores:
Usage
A development setup is used by default. Similar to std/log.
All logs are written to stderr.
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.
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 that you control. It can serve as HTTP handler, 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.
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
Documentation
¶
Index ¶
- func CapturePanic()
- func DPanic(args ...interface{})
- func DPanicf(template string, args ...interface{})
- func DPanicw(msg string, keysAndValues ...interface{})
- func Debug(args ...interface{})
- func Debugf(template string, args ...interface{})
- func Debugw(msg string, keysAndValues ...interface{})
- func Error(args ...interface{})
- func ErrorOutput(paths ...string) zap.Option
- func Errorf(template string, args ...interface{})
- func Errorw(msg string, keysAndValues ...interface{})
- func Fatal(args ...interface{})
- func Fatalf(template string, args ...interface{})
- func Fatalln(v ...interface{})
- func Fatalw(msg string, keysAndValues ...interface{})
- func Info(args ...interface{})
- func Infof(template string, args ...interface{})
- func Infow(msg string, keysAndValues ...interface{})
- func Named(name string) *zap.SugaredLogger
- func NewDevelopmentConfig() zap.Config
- func NewDevelopmentEncoderConfig() zapcore.EncoderConfig
- func Panic(args ...interface{})
- func Panicf(template string, args ...interface{})
- func Panicln(v ...interface{})
- func Panicw(msg string, keysAndValues ...interface{})
- func Print(v ...interface{})
- func Printf(format string, v ...interface{})
- func Println(v ...interface{})
- func Sampling(initial, thereafter int) zap.Option
- func Sync() error
- func Use(logger *zap.Logger)
- func Warn(args ...interface{})
- func Warnf(template string, args ...interface{})
- func Warnw(msg string, keysAndValues ...interface{})
- func With(args ...interface{}) *zap.SugaredLogger
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func CapturePanic ¶
func CapturePanic()
CapturePanic captures, logs and re-throws a panic. Only useful when used with defer.
func ErrorOutput ¶
ErrorOutput is a convenience function that creates a zapcore.WriteSyncer and returns it as zap.ErrorOutput option. It panics if path can't be opened. Example: ErrorOutput("stderr")
func Named ¶
func Named(name string) *zap.SugaredLogger
func NewDevelopmentConfig ¶
func NewDevelopmentEncoderConfig ¶
func NewDevelopmentEncoderConfig() zapcore.EncoderConfig
func Sampling ¶
Sampling is a convenience function that returns a zap.Option which wraps a core with a sample policy.
func With ¶
func With(args ...interface{}) *zap.SugaredLogger
Types ¶
This section is empty.
Source Files
Directories