README
¶
logger
logger is a library for writing structured json logs to stderr.
It is a wrapper around logrus that automatically formats as JSON and provides some default context (env, pid, host, and caller). It can capture output written to the default logger (since external dependencies will not be using this logger), and can add a rollbar rollbar hook to send all errors/panics/fatals to rollbar.
Usage
To use logger, just import this library, then call logger.Init(<level>)
from your main or init.
Then, you can log output using functions like logger.Infoln("message") and
logger.Fatal("ohno"). See the
logrus documentation for more functions you can
use.
To use the rollbar logger, initialize with:
logger.InitWithRollbar(<level>, <token>, <env>)
Add this to main to send all top level panics to rollbar:
defer logger.LogPanic()
To capture and log panics in other goroutines, spawn them with
logger.Go( <func> )
When using logger.Go, be careful about variables in loops. Unlike normal goroutines, you can't pass arguments (including objects with methods called on them). As an example, to convert:
for i, o := range objects {
go o.worker(i)
}
you will need to do one of the two following:
// Turn the loop variables into local function variables.
for i, o := range objects {
logger.Go(func(o Obj, i int) func() {
return func() { o.worker(i) }
}(o, i))
}
or
// Alias the loop variables in the block scope.
for i, o := range objects {
i := i
o := o
logger.Go(func() { o.worker(i) })
}
If you don't do one of the above, i and o will be shared across all goroutine invocations,
which means that they will probably be the value of the last iteration of the loop.
And in your shutdown code, include logger.Wait() to wait for any remaining
logs to be sent to rollbar before exiting.
Capturing default logger output
To capture output from the default logger, use logger.CaptureDefault().
To create a golang logger that will have its output forwarded to logger, use
logger.GetCapturedLogger().
If you do these, don't provide additional configuration to the captured logger,
or you may break the capturing.
Documentation
¶
Overview ¶
Package logger is a wrapper around logrus that logs in a structured JSON format and provides additional context keys. To use this library, first call `logger.Init("info")` or logger.InitWithRollbar(...), then call logging functions e.g. `logger.Infoln("message")`. You can also use CaptureDefault() to capture output that would go to the default logger (e.g. from dependencies).
Index ¶
- func CaptureDefault()
- func Debug(args ...interface{})
- func Debugf(format string, args ...interface{})
- func Debugln(args ...interface{})
- func Error(args ...interface{})
- func Errorf(format string, args ...interface{})
- func Errorln(args ...interface{})
- func Fatal(args ...interface{})
- func Fatalf(format string, args ...interface{})
- func Fatalln(args ...interface{})
- func GetCapturedLogger() *log.Logger
- func Go(f func())
- func Info(args ...interface{})
- func Infof(format string, args ...interface{})
- func Infoln(args ...interface{})
- func Init(level string)
- func InitLocal(level string)
- func InitWithRollbar(level, rollbarToken, rollbarEnv string)
- func LogPanic()
- func NewRollbarHook(token string, env string, levels []logrus.Level) logrus.Hook
- func Panic(args ...interface{})
- func Panicf(format string, args ...interface{})
- func Panicln(args ...interface{})
- func Print(args ...interface{})
- func Printf(format string, args ...interface{})
- func Println(args ...interface{})
- func Wait()
- func Warn(args ...interface{})
- func Warnf(format string, args ...interface{})
- func Warning(args ...interface{})
- func Warningf(format string, args ...interface{})
- func Warningln(args ...interface{})
- func Warnln(args ...interface{})
- type Entry
- func (entry *Entry) Debug(args ...interface{})
- func (entry *Entry) Debugf(format string, args ...interface{})
- func (entry *Entry) Debugln(args ...interface{})
- func (entry *Entry) Error(args ...interface{})
- func (entry *Entry) Errorf(format string, args ...interface{})
- func (entry *Entry) Errorln(args ...interface{})
- func (entry *Entry) Fatal(args ...interface{})
- func (entry *Entry) Fatalf(format string, args ...interface{})
- func (entry *Entry) Fatalln(args ...interface{})
- func (entry *Entry) Info(args ...interface{})
- func (entry *Entry) Infof(format string, args ...interface{})
- func (entry *Entry) Infoln(args ...interface{})
- func (entry *Entry) Panic(args ...interface{})
- func (entry *Entry) Panicf(format string, args ...interface{})
- func (entry *Entry) Panicln(args ...interface{})
- func (entry *Entry) Print(args ...interface{})
- func (entry *Entry) Printf(format string, args ...interface{})
- func (entry *Entry) Println(args ...interface{})
- func (entry *Entry) Warn(args ...interface{})
- func (entry *Entry) Warnf(format string, args ...interface{})
- func (entry *Entry) Warning(args ...interface{})
- func (entry *Entry) Warningf(format string, args ...interface{})
- func (entry *Entry) Warningln(args ...interface{})
- func (entry *Entry) Warnln(args ...interface{})
- func (entry *Entry) WithError(err error) *Entry
- func (entry *Entry) WithField(key string, value interface{}) *Entry
- func (entry *Entry) WithFields(fields logrus.Fields) *Entry
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func CaptureDefault ¶
func CaptureDefault()
CaptureDefault causes all outupt to the default logger to be redirected to the logrus logger at the Warn level.
func Debugf ¶
func Debugf(format string, args ...interface{})
Debugf logs the formatted string at Debug level.
func Errorf ¶
func Errorf(format string, args ...interface{})
Errorf logs the formatted string at Error level.
func Fatalf ¶
func Fatalf(format string, args ...interface{})
Fatalf logs the formatted string at Error level and exits.
func Fatalln ¶
func Fatalln(args ...interface{})
Fatalln logs the args at the Error level and exits.
func GetCapturedLogger ¶
GetCapturedLogger returns a *log.Logger with its output redirected to the logrus logger at the Warn level.
func Go ¶
func Go(f func())
Go spawns a goroutine like `go`, but captures and logs any panics that happen in them. Turn `go g()` into `logger.Go(func(){g()})
func Infof ¶
func Infof(format string, args ...interface{})
Infof logs the formatted string at Info level.
func InitLocal ¶
func InitLocal(level string)
InitLocal sets up logging at the given level for local consumption.
func InitWithRollbar ¶
func InitWithRollbar(level, rollbarToken, rollbarEnv string)
InitWithRollbar sets up logging at the given level, and sends log message of level panic, fatal, and error to rollbar. If rollbarToken isn't properly set, it will initialize the logrus logger without rollbar and move on, logging a message once the error response comes back from rollbar. In your main shutdown code, be sure to call rollbar.Wait() to guarantee late errors get sent to rollbar.
func LogPanic ¶
func LogPanic()
LogPanic catches any raw panics and logs them. Triggers another panic.
func NewRollbarHook ¶
NewRollbarHook creates a Rollbar hook for logrus.
func Panicf ¶
func Panicf(format string, args ...interface{})
Panicf logs the formatted string at Error level and panics.
func Panicln ¶
func Panicln(args ...interface{})
Panicln logs the args at the Error level and panics.
func Printf ¶
func Printf(format string, args ...interface{})
Printf logs the formatted string at Info level.
func Warnf ¶
func Warnf(format string, args ...interface{})
Warnf logs the formatted string at Warn level.
Types ¶
type Entry ¶
func WithFields ¶
WithFields creates an Entry with the given fields added.
func (*Entry) Debug ¶
func (entry *Entry) Debug(args ...interface{})
Debug logs the args at the Debug level.
func (*Entry) Debugln ¶
func (entry *Entry) Debugln(args ...interface{})
Debugln logs the args at the Debug level.
func (*Entry) Error ¶
func (entry *Entry) Error(args ...interface{})
Error logs the args at the Error level.
func (*Entry) Errorln ¶
func (entry *Entry) Errorln(args ...interface{})
Errorln logs the args at the Error level.
func (*Entry) Fatal ¶
func (entry *Entry) Fatal(args ...interface{})
Fatal logs the args at the Error level and exits.
func (*Entry) Fatalln ¶
func (entry *Entry) Fatalln(args ...interface{})
Fatalln logs the args at the Error level and exits.
func (*Entry) Info ¶
func (entry *Entry) Info(args ...interface{})
Info logs the args at the Info level.
func (*Entry) Infoln ¶
func (entry *Entry) Infoln(args ...interface{})
Infoln logs the args at the Info level.
func (*Entry) Panic ¶
func (entry *Entry) Panic(args ...interface{})
Panic logs the args at the Error level and panics.
func (*Entry) Panicln ¶
func (entry *Entry) Panicln(args ...interface{})
Panicln logs the args at the Error level and panics.
func (*Entry) Print ¶
func (entry *Entry) Print(args ...interface{})
Print logs the args at the Info level.
func (*Entry) Println ¶
func (entry *Entry) Println(args ...interface{})
Println logs the args at the Info level.
func (*Entry) Warn ¶
func (entry *Entry) Warn(args ...interface{})
Warn logs the args at the Warn level.
func (*Entry) Warning ¶
func (entry *Entry) Warning(args ...interface{})
Warning logs the args at the Warn level.
func (*Entry) Warningln ¶
func (entry *Entry) Warningln(args ...interface{})
Warningln logs the args at the Warn level.
Source Files