logrus: github.com/sirupsen/logrus Index | Files | Directories

package logrus

import "github.com/sirupsen/logrus"

Package logrus is a structured logger for Go, completely API compatible with the standard library logger.

The simplest way to use Logrus is simply the package-level exported logger:

package main

import (
  log "github.com/Sirupsen/logrus"
)

func main() {
  log.WithFields(log.Fields{
    "animal": "walrus",
    "number": 1,
    "size":   10,
  }).Info("A walrus appears")
}

Output:

time="2015-09-07T08:48:33Z" level=info msg="A walrus appears" animal=walrus number=1 size=10

For a full guide visit https://github.com/Sirupsen/logrus

Index

Package Files

alt_exit.go doc.go entry.go exported.go formatter.go hooks.go json_formatter.go logger.go logrus.go terminal_linux.go terminal_notwindows.go text_formatter.go writer.go

Constants

const (
    FieldKeyMsg   = "msg"
    FieldKeyLevel = "level"
    FieldKeyTime  = "time"
)
const DefaultTimestampFormat = time.RFC3339

Variables

var AllLevels = []Level{
    PanicLevel,
    FatalLevel,
    ErrorLevel,
    WarnLevel,
    InfoLevel,
    DebugLevel,
}

A constant exposing all logging levels

var ErrorKey = "error"

Defines the key when adding errors using WithError.

func AddHook Uses

func AddHook(hook Hook)

AddHook adds a hook to the standard logger hooks.

func Debug Uses

func Debug(args ...interface{})

Debug logs a message at level Debug on the standard logger.

func Debugf Uses

func Debugf(format string, args ...interface{})

Debugf logs a message at level Debug on the standard logger.

func Debugln Uses

func Debugln(args ...interface{})

Debugln logs a message at level Debug on the standard logger.

func Error Uses

func Error(args ...interface{})

Error logs a message at level Error on the standard logger.

func Errorf Uses

func Errorf(format string, args ...interface{})

Errorf logs a message at level Error on the standard logger.

func Errorln Uses

func Errorln(args ...interface{})

Errorln logs a message at level Error on the standard logger.

func Exit Uses

func Exit(code int)

Exit runs all the Logrus atexit handlers and then terminates the program using os.Exit(code)

func Fatal Uses

func Fatal(args ...interface{})

Fatal logs a message at level Fatal on the standard logger.

func Fatalf Uses

func Fatalf(format string, args ...interface{})

Fatalf logs a message at level Fatal on the standard logger.

func Fatalln Uses

func Fatalln(args ...interface{})

Fatalln logs a message at level Fatal on the standard logger.

func Info Uses

func Info(args ...interface{})

Info logs a message at level Info on the standard logger.

func Infof Uses

func Infof(format string, args ...interface{})

Infof logs a message at level Info on the standard logger.

func Infoln Uses

func Infoln(args ...interface{})

Infoln logs a message at level Info on the standard logger.

func IsTerminal Uses

func IsTerminal() bool

IsTerminal returns true if stderr's file descriptor is a terminal.

func Panic Uses

func Panic(args ...interface{})

Panic logs a message at level Panic on the standard logger.

func Panicf Uses

func Panicf(format string, args ...interface{})

Panicf logs a message at level Panic on the standard logger.

func Panicln Uses

func Panicln(args ...interface{})

Panicln logs a message at level Panic on the standard logger.

func Print Uses

func Print(args ...interface{})

Print logs a message at level Info on the standard logger.

func Printf Uses

func Printf(format string, args ...interface{})

Printf logs a message at level Info on the standard logger.

func Println Uses

func Println(args ...interface{})

Println logs a message at level Info on the standard logger.

func RegisterExitHandler Uses

func RegisterExitHandler(handler func())

RegisterExitHandler adds a Logrus Exit handler, call logrus.Exit to invoke all handlers. The handlers will also be invoked when any Fatal log entry is made.

This method is useful when a caller wishes to use logrus to log a fatal message but also needs to gracefully shutdown. An example usecase could be closing database connections, or sending a alert that the application is closing.

func SetFormatter Uses

func SetFormatter(formatter Formatter)

SetFormatter sets the standard logger formatter.

func SetLevel Uses

func SetLevel(level Level)

SetLevel sets the standard logger level.

func SetOutput Uses

func SetOutput(out io.Writer)

SetOutput sets the standard logger output.

func Warn Uses

func Warn(args ...interface{})

Warn logs a message at level Warn on the standard logger.

func Warnf Uses

func Warnf(format string, args ...interface{})

Warnf logs a message at level Warn on the standard logger.

func Warning Uses

func Warning(args ...interface{})

Warning logs a message at level Warn on the standard logger.

func Warningf Uses

func Warningf(format string, args ...interface{})

Warningf logs a message at level Warn on the standard logger.

func Warningln Uses

func Warningln(args ...interface{})

Warningln logs a message at level Warn on the standard logger.

func Warnln Uses

func Warnln(args ...interface{})

Warnln logs a message at level Warn on the standard logger.

type Entry Uses

type Entry struct {
    Logger *Logger

    // Contains all the fields set by the user.
    Data Fields

    // Time at which the log entry was created
    Time time.Time

    // Level the log entry was logged at: Debug, Info, Warn, Error, Fatal or Panic
    Level Level

    // Message passed to Debug, Info, Warn, Error, Fatal or Panic
    Message string

    // When formatter is called in entry.log(), an Buffer may be set to entry
    Buffer *bytes.Buffer
}

An entry is the final or intermediate Logrus logging entry. It contains all the fields passed with WithField{,s}. It's finally logged when Debug, Info, Warn, Error, Fatal or Panic is called on it. These objects can be reused and passed around as much as you wish to avoid field duplication.

func NewEntry Uses

func NewEntry(logger *Logger) *Entry

func WithError Uses

func WithError(err error) *Entry

WithError creates an entry from the standard logger and adds an error to it, using the value defined in ErrorKey as key.

func WithField Uses

func WithField(key string, value interface{}) *Entry

WithField creates an entry from the standard logger and adds a field to it. If you want multiple fields, use `WithFields`.

Note that it doesn't log until you call Debug, Print, Info, Warn, Fatal or Panic on the Entry it returns.

func WithFields Uses

func WithFields(fields Fields) *Entry

WithFields creates an entry from the standard logger and adds multiple fields to it. This is simply a helper for `WithField`, invoking it once for each field.

Note that it doesn't log until you call Debug, Print, Info, Warn, Fatal or Panic on the Entry it returns.

func (*Entry) Debug Uses

func (entry *Entry) Debug(args ...interface{})

func (*Entry) Debugf Uses

func (entry *Entry) Debugf(format string, args ...interface{})

func (*Entry) Debugln Uses

func (entry *Entry) Debugln(args ...interface{})

func (*Entry) Error Uses

func (entry *Entry) Error(args ...interface{})

func (*Entry) Errorf Uses

func (entry *Entry) Errorf(format string, args ...interface{})

func (*Entry) Errorln Uses

func (entry *Entry) Errorln(args ...interface{})

func (*Entry) Fatal Uses

func (entry *Entry) Fatal(args ...interface{})

func (*Entry) Fatalf Uses

func (entry *Entry) Fatalf(format string, args ...interface{})

func (*Entry) Fatalln Uses

func (entry *Entry) Fatalln(args ...interface{})

func (*Entry) Info Uses

func (entry *Entry) Info(args ...interface{})

func (*Entry) Infof Uses

func (entry *Entry) Infof(format string, args ...interface{})

func (*Entry) Infoln Uses

func (entry *Entry) Infoln(args ...interface{})

func (*Entry) Panic Uses

func (entry *Entry) Panic(args ...interface{})

func (*Entry) Panicf Uses

func (entry *Entry) Panicf(format string, args ...interface{})

func (*Entry) Panicln Uses

func (entry *Entry) Panicln(args ...interface{})

func (*Entry) Print Uses

func (entry *Entry) Print(args ...interface{})

func (*Entry) Printf Uses

func (entry *Entry) Printf(format string, args ...interface{})

func (*Entry) Println Uses

func (entry *Entry) Println(args ...interface{})

func (*Entry) String Uses

func (entry *Entry) String() (string, error)

Returns the string representation from the reader and ultimately the formatter.

func (*Entry) Warn Uses

func (entry *Entry) Warn(args ...interface{})

func (*Entry) Warnf Uses

func (entry *Entry) Warnf(format string, args ...interface{})

func (*Entry) Warning Uses

func (entry *Entry) Warning(args ...interface{})

func (*Entry) Warningf Uses

func (entry *Entry) Warningf(format string, args ...interface{})

func (*Entry) Warningln Uses

func (entry *Entry) Warningln(args ...interface{})

func (*Entry) Warnln Uses

func (entry *Entry) Warnln(args ...interface{})

func (*Entry) WithError Uses

func (entry *Entry) WithError(err error) *Entry

Add an error as single field (using the key defined in ErrorKey) to the Entry.

func (*Entry) WithField Uses

func (entry *Entry) WithField(key string, value interface{}) *Entry

Add a single field to the Entry.

func (*Entry) WithFields Uses

func (entry *Entry) WithFields(fields Fields) *Entry

Add a map of fields to the Entry.

type FieldLogger Uses

type FieldLogger interface {
    WithField(key string, value interface{}) *Entry
    WithFields(fields Fields) *Entry
    WithError(err error) *Entry

    Debugf(format string, args ...interface{})
    Infof(format string, args ...interface{})
    Printf(format string, args ...interface{})
    Warnf(format string, args ...interface{})
    Warningf(format string, args ...interface{})
    Errorf(format string, args ...interface{})
    Fatalf(format string, args ...interface{})
    Panicf(format string, args ...interface{})

    Debug(args ...interface{})
    Info(args ...interface{})
    Print(args ...interface{})
    Warn(args ...interface{})
    Warning(args ...interface{})
    Error(args ...interface{})
    Fatal(args ...interface{})
    Panic(args ...interface{})

    Debugln(args ...interface{})
    Infoln(args ...interface{})
    Println(args ...interface{})
    Warnln(args ...interface{})
    Warningln(args ...interface{})
    Errorln(args ...interface{})
    Fatalln(args ...interface{})
    Panicln(args ...interface{})
}

The FieldLogger interface generalizes the Entry and Logger types

type FieldMap Uses

type FieldMap map[fieldKey]string

type Fields Uses

type Fields map[string]interface{}

Fields type, used to pass to `WithFields`.

type Formatter Uses

type Formatter interface {
    Format(*Entry) ([]byte, error)
}

The Formatter interface is used to implement a custom Formatter. It takes an `Entry`. It exposes all the fields, including the default ones:

* `entry.Data["msg"]`. The message passed from Info, Warn, Error .. * `entry.Data["time"]`. The timestamp. * `entry.Data["level"]. The level the entry was logged at.

Any additional fields added with `WithField` or `WithFields` are also in `entry.Data`. Format is expected to return an array of bytes which are then logged to `logger.Out`.

type Hook Uses

type Hook interface {
    Levels() []Level
    Fire(*Entry) error
}

A hook to be fired when logging on the logging levels returned from `Levels()` on your implementation of the interface. Note that this is not fired in a goroutine or a channel with workers, you should handle such functionality yourself if your call is non-blocking and you don't wish for the logging calls for levels returned from `Levels()` to block.

type JSONFormatter Uses

type JSONFormatter struct {
    // TimestampFormat sets the format used for marshaling timestamps.
    TimestampFormat string

    // DisableTimestamp allows disabling automatic timestamps in output
    DisableTimestamp bool

    // FieldMap allows users to customize the names of keys for various fields.
    // As an example:
    // formatter := &JSONFormatter{
    //   	FieldMap: FieldMap{
    // 		 FieldKeyTime: "@timestamp",
    // 		 FieldKeyLevel: "@level",
    // 		 FieldKeyLevel: "@message",
    //    },
    // }
    FieldMap FieldMap
}

func (*JSONFormatter) Format Uses

func (f *JSONFormatter) Format(entry *Entry) ([]byte, error)

type Level Uses

type Level uint8

Level type

const (
    // PanicLevel level, highest level of severity. Logs and then calls panic with the
    // message passed to Debug, Info, ...
    PanicLevel Level = iota
    // FatalLevel level. Logs and then calls `os.Exit(1)`. It will exit even if the
    // logging level is set to Panic.
    FatalLevel
    // ErrorLevel level. Logs. Used for errors that should definitely be noted.
    // Commonly used for hooks to send errors to an error tracking service.
    ErrorLevel
    // WarnLevel level. Non-critical entries that deserve eyes.
    WarnLevel
    // InfoLevel level. General operational entries about what's going on inside the
    // application.
    InfoLevel
    // DebugLevel level. Usually only enabled when debugging. Very verbose logging.
    DebugLevel
)

These are the different logging levels. You can set the logging level to log on your instance of logger, obtained with `logrus.New()`.

func GetLevel Uses

func GetLevel() Level

GetLevel returns the standard logger level.

func ParseLevel Uses

func ParseLevel(lvl string) (Level, error)

ParseLevel takes a string level and returns the Logrus log level constant.

func (Level) String Uses

func (level Level) String() string

Convert the Level to a string. E.g. PanicLevel becomes "panic".

type LevelHooks Uses

type LevelHooks map[Level][]Hook

Internal type for storing the hooks on a logger instance.

func (LevelHooks) Add Uses

func (hooks LevelHooks) Add(hook Hook)

Add a hook to an instance of logger. This is called with `log.Hooks.Add(new(MyHook))` where `MyHook` implements the `Hook` interface.

func (LevelHooks) Fire Uses

func (hooks LevelHooks) Fire(level Level, entry *Entry) error

Fire all the hooks for the passed level. Used by `entry.log` to fire appropriate hooks for a log entry.

type Logger Uses

type Logger struct {
    // The logs are `io.Copy`'d to this in a mutex. It's common to set this to a
    // file, or leave it default which is `os.Stderr`. You can also set this to
    // something more adventorous, such as logging to Kafka.
    Out io.Writer
    // Hooks for the logger instance. These allow firing events based on logging
    // levels and log entries. For example, to send errors to an error tracking
    // service, log to StatsD or dump the core on fatal errors.
    Hooks LevelHooks
    // All log entries pass through the formatter before logged to Out. The
    // included formatters are `TextFormatter` and `JSONFormatter` for which
    // TextFormatter is the default. In development (when a TTY is attached) it
    // logs with colors, but to a file it wouldn't. You can easily implement your
    // own that implements the `Formatter` interface, see the `README` or included
    // formatters for examples.
    Formatter Formatter
    // The logging level the logger should log at. This is typically (and defaults
    // to) `logrus.Info`, which allows Info(), Warn(), Error() and Fatal() to be
    // logged. `logrus.Debug` is useful in
    Level Level
    // contains filtered or unexported fields
}

func New Uses

func New() *Logger

Creates a new logger. Configuration should be set by changing `Formatter`, `Out` and `Hooks` directly on the default logger instance. You can also just instantiate your own:

var log = &Logger{
  Out: os.Stderr,
  Formatter: new(JSONFormatter),
  Hooks: make(LevelHooks),
  Level: logrus.DebugLevel,
}

It's recommended to make this a global instance called `log`.

func StandardLogger Uses

func StandardLogger() *Logger

func (*Logger) Debug Uses

func (logger *Logger) Debug(args ...interface{})

func (*Logger) Debugf Uses

func (logger *Logger) Debugf(format string, args ...interface{})

func (*Logger) Debugln Uses

func (logger *Logger) Debugln(args ...interface{})

func (*Logger) Error Uses

func (logger *Logger) Error(args ...interface{})

func (*Logger) Errorf Uses

func (logger *Logger) Errorf(format string, args ...interface{})

func (*Logger) Errorln Uses

func (logger *Logger) Errorln(args ...interface{})

func (*Logger) Fatal Uses

func (logger *Logger) Fatal(args ...interface{})

func (*Logger) Fatalf Uses

func (logger *Logger) Fatalf(format string, args ...interface{})

func (*Logger) Fatalln Uses

func (logger *Logger) Fatalln(args ...interface{})

func (*Logger) Info Uses

func (logger *Logger) Info(args ...interface{})

func (*Logger) Infof Uses

func (logger *Logger) Infof(format string, args ...interface{})

func (*Logger) Infoln Uses

func (logger *Logger) Infoln(args ...interface{})

func (*Logger) Panic Uses

func (logger *Logger) Panic(args ...interface{})

func (*Logger) Panicf Uses

func (logger *Logger) Panicf(format string, args ...interface{})

func (*Logger) Panicln Uses

func (logger *Logger) Panicln(args ...interface{})

func (*Logger) Print Uses

func (logger *Logger) Print(args ...interface{})

func (*Logger) Printf Uses

func (logger *Logger) Printf(format string, args ...interface{})

func (*Logger) Println Uses

func (logger *Logger) Println(args ...interface{})

func (*Logger) SetNoLock Uses

func (logger *Logger) SetNoLock()

When file is opened with appending mode, it's safe to write concurrently to a file (within 4k message on Linux). In these cases user can choose to disable the lock.

func (*Logger) Warn Uses

func (logger *Logger) Warn(args ...interface{})

func (*Logger) Warnf Uses

func (logger *Logger) Warnf(format string, args ...interface{})

func (*Logger) Warning Uses

func (logger *Logger) Warning(args ...interface{})

func (*Logger) Warningf Uses

func (logger *Logger) Warningf(format string, args ...interface{})

func (*Logger) Warningln Uses

func (logger *Logger) Warningln(args ...interface{})

func (*Logger) Warnln Uses

func (logger *Logger) Warnln(args ...interface{})

func (*Logger) WithError Uses

func (logger *Logger) WithError(err error) *Entry

Add an error as single field to the log entry. All it does is call `WithError` for the given `error`.

func (*Logger) WithField Uses

func (logger *Logger) WithField(key string, value interface{}) *Entry

Adds a field to the log entry, note that it doesn't log until you call Debug, Print, Info, Warn, Fatal or Panic. It only creates a log entry. If you want multiple fields, use `WithFields`.

func (*Logger) WithFields Uses

func (logger *Logger) WithFields(fields Fields) *Entry

Adds a struct of fields to the log entry. All it does is call `WithField` for each `Field`.

func (*Logger) Writer Uses

func (logger *Logger) Writer() *io.PipeWriter

func (*Logger) WriterLevel Uses

func (logger *Logger) WriterLevel(level Level) *io.PipeWriter

type MutexWrap Uses

type MutexWrap struct {
    // contains filtered or unexported fields
}

func (*MutexWrap) Disable Uses

func (mw *MutexWrap) Disable()

func (*MutexWrap) Lock Uses

func (mw *MutexWrap) Lock()

func (*MutexWrap) Unlock Uses

func (mw *MutexWrap) Unlock()

type StdLogger Uses

type StdLogger interface {
    Print(...interface{})
    Printf(string, ...interface{})
    Println(...interface{})

    Fatal(...interface{})
    Fatalf(string, ...interface{})
    Fatalln(...interface{})

    Panic(...interface{})
    Panicf(string, ...interface{})
    Panicln(...interface{})
}

StdLogger is what your logrus-enabled library should take, that way it'll accept a stdlib logger and a logrus logger. There's no standard interface, this is the closest we get, unfortunately.

type Termios Uses

type Termios syscall.Termios

type TextFormatter Uses

type TextFormatter struct {
    // Set to true to bypass checking for a TTY before outputting colors.
    ForceColors bool

    // Force disabling colors.
    DisableColors bool

    // Disable timestamp logging. useful when output is redirected to logging
    // system that already adds timestamps.
    DisableTimestamp bool

    // Enable logging the full timestamp when a TTY is attached instead of just
    // the time passed since beginning of execution.
    FullTimestamp bool

    // TimestampFormat to use for display when a full timestamp is printed
    TimestampFormat string

    // The fields are sorted by default for a consistent output. For applications
    // that log extremely frequently and don't use the JSON formatter this may not
    // be desired.
    DisableSorting bool
}

func (*TextFormatter) Format Uses

func (f *TextFormatter) Format(entry *Entry) ([]byte, error)

Directories

PathSynopsis
examples/basic
examples/hook
hooks/syslog
hooks/test

Package logrus imports 14 packages (graph) and is imported by 81 packages. Updated 2017-01-19. Refresh now. Tools for package owners.