Documentation ¶
Overview ¶
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 ¶
- Constants
- Variables
- func AddHook(hook Hook)
- 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 Exit(code int)
- func Fatal(args ...interface{})
- func Fatalf(format string, args ...interface{})
- func Fatalln(args ...interface{})
- func Info(args ...interface{})
- func Infof(format string, args ...interface{})
- func Infoln(args ...interface{})
- func IsTerminal(f io.Writer) bool
- 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 RegisterExitHandler(handler func())
- func SetFormatter(formatter Formatter)
- func SetLevel(level Level)
- func SetOutput(out io.Writer)
- 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) String() (string, error)
- 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 Fields) *Entry
- type FieldLogger
- type FieldMap
- type Fields
- type Formatter
- type Hook
- type JSONFormatter
- type Level
- type LevelHooks
- type Logger
- func (logger *Logger) Debug(args ...interface{})
- func (logger *Logger) Debugf(format string, args ...interface{})
- func (logger *Logger) Debugln(args ...interface{})
- func (logger *Logger) Error(args ...interface{})
- func (logger *Logger) Errorf(format string, args ...interface{})
- func (logger *Logger) Errorln(args ...interface{})
- func (logger *Logger) Fatal(args ...interface{})
- func (logger *Logger) Fatalf(format string, args ...interface{})
- func (logger *Logger) Fatalln(args ...interface{})
- func (logger *Logger) Info(args ...interface{})
- func (logger *Logger) Infof(format string, args ...interface{})
- func (logger *Logger) Infoln(args ...interface{})
- func (logger *Logger) Panic(args ...interface{})
- func (logger *Logger) Panicf(format string, args ...interface{})
- func (logger *Logger) Panicln(args ...interface{})
- func (logger *Logger) Print(args ...interface{})
- func (logger *Logger) Printf(format string, args ...interface{})
- func (logger *Logger) Println(args ...interface{})
- func (logger *Logger) SetNoLock()
- func (logger *Logger) Warn(args ...interface{})
- func (logger *Logger) Warnf(format string, args ...interface{})
- func (logger *Logger) Warning(args ...interface{})
- func (logger *Logger) Warningf(format string, args ...interface{})
- func (logger *Logger) Warningln(args ...interface{})
- func (logger *Logger) Warnln(args ...interface{})
- func (logger *Logger) WithError(err error) *Entry
- func (logger *Logger) WithField(key string, value interface{}) *Entry
- func (logger *Logger) WithFields(fields Fields) *Entry
- func (logger *Logger) Writer() *io.PipeWriter
- func (logger *Logger) WriterLevel(level Level) *io.PipeWriter
- type MutexWrap
- type StdLogger
- type Termios
- type TextFormatter
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.
Functions ¶
func AddHook ¶ added in v0.4.0
func AddHook(hook Hook)
AddHook adds a hook to the standard logger hooks.
func Debug ¶
func Debug(args ...interface{})
Debug logs a message at level Debug on the standard logger.
func Debugf ¶ added in v0.4.1
func Debugf(format string, args ...interface{})
Debugf logs a message at level Debug on the standard logger.
func Debugln ¶ added in v0.4.1
func Debugln(args ...interface{})
Debugln logs a message at level Debug on the standard logger.
func Error ¶
func Error(args ...interface{})
Error logs a message at level Error on the standard logger.
func Errorf ¶ added in v0.4.1
func Errorf(format string, args ...interface{})
Errorf logs a message at level Error on the standard logger.
func Errorln ¶ added in v0.4.1
func Errorln(args ...interface{})
Errorln logs a message at level Error on the standard logger.
func Exit ¶ added in v0.11.0
func Exit(code int)
Exit runs all the Logrus atexit handlers and then terminates the program using os.Exit(code)
func Fatal ¶
func Fatal(args ...interface{})
Fatal logs a message at level Fatal on the standard logger.
func Fatalf ¶ added in v0.4.1
func Fatalf(format string, args ...interface{})
Fatalf logs a message at level Fatal on the standard logger.
func Fatalln ¶ added in v0.4.1
func Fatalln(args ...interface{})
Fatalln logs a message at level Fatal on the standard logger.
func Info ¶
func Info(args ...interface{})
Info logs a message at level Info on the standard logger.
func Infof ¶ added in v0.4.1
func Infof(format string, args ...interface{})
Infof logs a message at level Info on the standard logger.
func Infoln ¶ added in v0.4.1
func Infoln(args ...interface{})
Infoln logs a message at level Info on the standard logger.
func IsTerminal ¶ added in v0.1.1
IsTerminal returns true if stderr's file descriptor is a terminal.
func Panic ¶
func Panic(args ...interface{})
Panic logs a message at level Panic on the standard logger.
func Panicf ¶ added in v0.4.1
func Panicf(format string, args ...interface{})
Panicf logs a message at level Panic on the standard logger.
func Panicln ¶ added in v0.4.1
func Panicln(args ...interface{})
Panicln logs a message at level Panic on the standard logger.
func Print ¶ added in v0.4.1
func Print(args ...interface{})
Print logs a message at level Info on the standard logger.
func Printf ¶ added in v0.4.1
func Printf(format string, args ...interface{})
Printf logs a message at level Info on the standard logger.
func Println ¶ added in v0.4.1
func Println(args ...interface{})
Println logs a message at level Info on the standard logger.
func RegisterExitHandler ¶ added in v0.11.0
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 ¶ added in v0.4.0
func SetFormatter(formatter Formatter)
SetFormatter sets the standard logger formatter.
func Warn ¶
func Warn(args ...interface{})
Warn logs a message at level Warn on the standard logger.
func Warnf ¶ added in v0.4.1
func Warnf(format string, args ...interface{})
Warnf logs a message at level Warn on the standard logger.
func Warning ¶ added in v0.4.1
func Warning(args ...interface{})
Warning logs a message at level Warn on the standard logger.
func Warningf ¶ added in v0.4.1
func Warningf(format string, args ...interface{})
Warningf logs a message at level Warn on the standard logger.
Types ¶
type Entry ¶
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 WithError ¶ added in v0.8.7
WithError creates an entry from the standard logger and adds an error to it, using the value defined in ErrorKey as key.
func WithField ¶ added in v0.4.0
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 ¶ added in v0.4.0
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) String ¶
Returns the string representation from the reader and ultimately the formatter.
func (*Entry) WithError ¶ added in v0.8.7
Add an error as single field (using the key defined in ErrorKey) to the Entry.
func (*Entry) WithFields ¶
Add a map of fields to the Entry.
type FieldLogger ¶ added in v0.10.0
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 Formatter ¶
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 ¶
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 ¶
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 }
type Level ¶
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 ParseLevel ¶ added in v0.6.0
ParseLevel takes a string level and returns the Logrus log level constant.
type LevelHooks ¶ added in v0.8.3
Internal type for storing the hooks on a logger instance.
func (LevelHooks) Add ¶ added in v0.8.3
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.
type Logger ¶
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 ¶
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 ¶ added in v0.6.5
func StandardLogger() *Logger
func (*Logger) SetNoLock ¶ added in v0.11.0
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) WithError ¶ added in v0.9.0
Add an error as single field to the log entry. All it does is call `WithError` for the given `error`.
func (*Logger) WithField ¶
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 ¶
Adds a struct of fields to the log entry. All it does is call `WithField` for each `Field`.
func (*Logger) Writer ¶ added in v0.6.5
func (logger *Logger) Writer() *io.PipeWriter
func (*Logger) WriterLevel ¶ added in v0.11.0
func (logger *Logger) WriterLevel(level Level) *io.PipeWriter
type MutexWrap ¶ added in v0.11.0
type MutexWrap struct {
// contains filtered or unexported fields
}
type StdLogger ¶
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 TextFormatter ¶
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 // contains filtered or unexported fields }