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 DeferExitHandler(handler func())
- 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 IsLevelEnabled(level Level) 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 SetReportCaller(include bool)
- func Trace(args ...interface{})
- func Tracef(format string, args ...interface{})
- func Traceln(args ...interface{})
- 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) HasCaller() (has bool)
- func (entry *Entry) Info(args ...interface{})
- func (entry *Entry) Infof(format string, args ...interface{})
- func (entry *Entry) Infoln(args ...interface{})
- func (entry *Entry) Log(level Level, args ...interface{})
- func (entry *Entry) Logf(level Level, format string, args ...interface{})
- func (entry *Entry) Logln(level Level, 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) Trace(args ...interface{})
- func (entry *Entry) Tracef(format string, args ...interface{})
- func (entry *Entry) Traceln(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) WithContext(ctx context.Context) *Entry
- func (entry *Entry) WithError(err error) *Entry
- func (entry *Entry) WithField(key string, value interface{}) *Entry
- func (entry *Entry) WithFields(fields Fields) *Entry
- func (entry *Entry) WithTime(t time.Time) *Entry
- func (entry *Entry) Writer() *io.PipeWriter
- func (entry *Entry) WriterLevel(level Level) *io.PipeWriter
- type Ext1FieldLogger
- type FieldLogger
- type FieldMap
- type Fields
- type Formatter
- type Hook
- type JSONFormatter
- type Level
- type LevelHooks
- type Logger
- func (logger *Logger) AddHook(hook Hook)
- 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) Exit(code int)
- func (logger *Logger) Fatal(args ...interface{})
- func (logger *Logger) Fatalf(format string, args ...interface{})
- func (logger *Logger) Fatalln(args ...interface{})
- func (logger *Logger) GetLevel() Level
- func (logger *Logger) Info(args ...interface{})
- func (logger *Logger) Infof(format string, args ...interface{})
- func (logger *Logger) Infoln(args ...interface{})
- func (logger *Logger) IsLevelEnabled(level Level) bool
- func (logger *Logger) Log(level Level, args ...interface{})
- func (logger *Logger) Logf(level Level, format string, args ...interface{})
- func (logger *Logger) Logln(level Level, 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) ReplaceHooks(hooks LevelHooks) LevelHooks
- func (logger *Logger) SetFormatter(formatter Formatter)
- func (logger *Logger) SetLevel(level Level)
- func (logger *Logger) SetNoLock()
- func (logger *Logger) SetOutput(output io.Writer)
- func (logger *Logger) SetReportCaller(reportCaller bool)
- func (logger *Logger) Trace(args ...interface{})
- func (logger *Logger) Tracef(format string, args ...interface{})
- func (logger *Logger) Traceln(args ...interface{})
- 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) WithContext(ctx context.Context) *Entry
- 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) WithTime(t time.Time) *Entry
- func (logger *Logger) Writer() *io.PipeWriter
- func (logger *Logger) WriterLevel(level Level) *io.PipeWriter
- type MutexWrap
- type StdLogger
- type TextFormatter
Constants ¶
const ( FieldKeyMsg = "msg" FieldKeyLevel = "level" FieldKeyTime = "time" FieldKeyLogrusError = "logrus_error" FieldKeyFunc = "func" FieldKeyFile = "file" )
Default key names for the default fields
Variables ¶
var AllLevels = []Level{ PanicLevel, FatalLevel, ErrorLevel, WarnLevel, InfoLevel, DebugLevel, TraceLevel, }
A constant exposing all logging levels
var ErrorKey = "error"
Defines the key when adding errors using WithError.
Functions ¶
func Debug ¶
func Debug(args ...interface{})
Debug logs a message at level Debug on the standard logger.
func Debugf ¶
func Debugf(format string, args ...interface{})
Debugf logs a message at level Debug on the standard logger.
func Debugln ¶
func Debugln(args ...interface{})
Debugln logs a message at level Debug on the standard logger.
func DeferExitHandler ¶
func DeferExitHandler(handler func())
DeferExitHandler prepends a Logrus Exit handler to the list of handlers, 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 Error ¶
func Error(args ...interface{})
Error logs a message at level Error on the standard logger.
func Errorf ¶
func Errorf(format string, args ...interface{})
Errorf logs a message at level Error on the standard logger.
func Errorln ¶
func Errorln(args ...interface{})
Errorln logs a message at level Error on the standard logger.
func Exit ¶
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 then the process will exit with status set to 1.
func Fatalf ¶
func Fatalf(format string, args ...interface{})
Fatalf logs a message at level Fatal on the standard logger then the process will exit with status set to 1.
func Fatalln ¶
func Fatalln(args ...interface{})
Fatalln logs a message at level Fatal on the standard logger then the process will exit with status set to 1.
func Info ¶
func Info(args ...interface{})
Info logs a message at level Info on the standard logger.
func Infof ¶
func Infof(format string, args ...interface{})
Infof logs a message at level Info on the standard logger.
func Infoln ¶
func Infoln(args ...interface{})
Infoln logs a message at level Info on the standard logger.
func IsLevelEnabled ¶
IsLevelEnabled checks if the log level of the standard logger is greater than the level param
func Panic ¶
func Panic(args ...interface{})
Panic logs a message at level Panic on the standard logger.
func Panicf ¶
func Panicf(format string, args ...interface{})
Panicf logs a message at level Panic on the standard logger.
func Panicln ¶
func Panicln(args ...interface{})
Panicln logs a message at level Panic on the standard logger.
func Print ¶
func Print(args ...interface{})
Print logs a message at level Info on the standard logger.
func Printf ¶
func Printf(format string, args ...interface{})
Printf logs a message at level Info on the standard logger.
func Println ¶
func Println(args ...interface{})
Println logs a message at level Info on the standard logger.
func RegisterExitHandler ¶
func RegisterExitHandler(handler func())
RegisterExitHandler appends a Logrus Exit handler to the list of handlers, 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 ¶
func SetFormatter(formatter Formatter)
SetFormatter sets the standard logger formatter.
func SetReportCaller ¶
func SetReportCaller(include bool)
SetReportCaller sets whether the standard logger will include the calling method as a field.
func Trace ¶
func Trace(args ...interface{})
Trace logs a message at level Trace on the standard logger.
func Tracef ¶
func Tracef(format string, args ...interface{})
Tracef logs a message at level Trace on the standard logger.
func Traceln ¶
func Traceln(args ...interface{})
Traceln logs a message at level Trace on the standard logger.
func Warn ¶
func Warn(args ...interface{})
Warn logs a message at level Warn on the standard logger.
func Warnf ¶
func Warnf(format string, args ...interface{})
Warnf logs a message at level Warn on the standard logger.
func Warning ¶
func Warning(args ...interface{})
Warning logs a message at level Warn on the standard logger.
func Warningf ¶
func Warningf(format string, args ...interface{})
Warningf logs a message at level Warn on the standard logger.
func Warningln ¶
func Warningln(args ...interface{})
Warningln logs a message at level Warn on the standard logger.
func Warnln ¶
func Warnln(args ...interface{})
Warnln 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: Trace, Debug, Info, Warn, Error, Fatal or Panic // This field will be set on entry firing and the value will be equal to the one in Logger struct field. Level Level // Calling method, with package name Caller *runtime.Frame // Message passed to Trace, Debug, Info, Warn, Error, Fatal or Panic Message string // When formatter is called in entry.log(), a Buffer may be set to entry Buffer *bytes.Buffer // Contains the context set by the user. Useful for hook processing etc. Context context.Context // contains filtered or unexported fields }
An entry is the final or intermediate Logrus logging entry. It contains all the fields passed with WithField{,s}. It's finally logged when Trace, 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 WithContext ¶
WithContext creates an entry from the standard logger and adds a context to it.
func WithError ¶
WithError creates an entry from the standard logger and adds an error to it, using the value defined in ErrorKey as key.
func WithField ¶
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 ¶
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 WithTime ¶
WithTime creats an entry from the standard logger and overrides the time of logs generated with it.
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) WithContext ¶
Add a context to the Entry.
func (*Entry) WithError ¶
Add an error as single field (using the key defined in ErrorKey) to the Entry.
func (*Entry) WithField ¶
Add a single field to the Entry.
func (*Entry) WithFields ¶
Add a map of fields to the Entry.
func (*Entry) WithTime ¶
Overrides the time of the Entry.
func (*Entry) Writer ¶
func (entry *Entry) Writer() *io.PipeWriter
func (*Entry) WriterLevel ¶
func (entry *Entry) WriterLevel(level Level) *io.PipeWriter
type Ext1FieldLogger ¶
type Ext1FieldLogger interface { FieldLogger Tracef(format string, args ...interface{}) Trace(args ...interface{}) Traceln(args ...interface{}) }
Ext1FieldLogger (the first extension to FieldLogger) is superfluous, it is here for consistancy. Do not use. Use Logger or Entry instead.
type FieldLogger ¶
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 ¶
type FieldMap map[fieldKey]string
FieldMap allows customization of the key names for default fields.
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 // DataKey allows users to put all the log entry parameters into a nested dictionary at a given key. DataKey string // FieldMap allows users to customize the names of keys for default fields. // As an example: // formatter := &JSONFormatter{ // FieldMap: FieldMap{ // FieldKeyTime: "@timestamp", // FieldKeyLevel: "@level", // FieldKeyMsg: "@message", // FieldKeyFunc: "@caller", // }, // } FieldMap FieldMap // CallerPrettyfier can be set by the user to modify the content // of the function and file keys in the json data when ReportCaller is // activated. If any of the returned value is the empty string the // corresponding key will be removed from json fields. CallerPrettyfier func(*runtime.Frame) (function string, file string) // PrettyPrint will indent all json logs PrettyPrint bool }
JSONFormatter formats logs into parsable json
func (*JSONFormatter) Format ¶
func (f *JSONFormatter) Format(entry *Entry) ([]byte, error)
Format renders a single log entry
type Level ¶
type Level uint32
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 `logger.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 // TraceLevel level. Designates finer-grained informational events than the Debug. TraceLevel )
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 ¶
ParseLevel takes a string level and returns the Logrus log level constant.
func (Level) String ¶
Convert the Level to a string. E.g. PanicLevel becomes "panic".
type LevelHooks ¶
Internal type for storing the hooks on a logger instance.
func (LevelHooks) Add ¶
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 ¶
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 ¶
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 adventurous, 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 // Flag for whether to log caller info (off by default) ReportCaller bool // 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. Level Level // Function to exit the application, defaults to `os.Exit()` ExitFunc exitFunc // 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 (*Logger) AddHook ¶
AddHook adds a hook to the logger hooks.
func (*Logger) IsLevelEnabled ¶
IsLevelEnabled checks if the log level of the logger is greater than the level param
func (*Logger) ReplaceHooks ¶
func (logger *Logger) ReplaceHooks(hooks LevelHooks) LevelHooks
ReplaceHooks replaces the logger hooks and returns the old ones
func (*Logger) SetFormatter ¶
SetFormatter sets the logger formatter.
func (*Logger) SetLevel ¶
SetLevel sets the logger level.
func (*Logger) SetNoLock ¶
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) SetOutput ¶
SetOutput sets the logger output.
func (*Logger) WithContext ¶
Add a context to the log entry.
func (*Logger) WithError ¶
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, Error, 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) WithTime ¶
Overrides the time of the log entry.
func (*Logger) Writer ¶
func (logger *Logger) Writer() *io.PipeWriter
func (*Logger) WriterLevel ¶
func (logger *Logger) WriterLevel(level Level) *io.PipeWriter
type MutexWrap ¶
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 // Override coloring based on CLICOLOR and CLICOLOR_FORCE. - https://bixense.com/clicolors/ EnvironmentOverrideColors 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 // The keys sorting function, when uninitialized it uses sort.Strings. SortingFunc func([]string) // Disables the truncation of the level text to 4 characters. DisableLevelTruncation bool // QuoteEmptyFields will wrap empty fields in quotes if true QuoteEmptyFields bool // FieldMap allows users to customize the names of keys for default fields. // As an example: // formatter := &TextFormatter{ // FieldMap: FieldMap{ // FieldKeyTime: "@timestamp", // FieldKeyLevel: "@level", // FieldKeyMsg: "@message"}} FieldMap FieldMap // CallerPrettyfier can be set by the user to modify the content // of the function and file keys in the data when ReportCaller is // activated. If any of the returned value is the empty string the // corresponding key will be removed from fields. CallerPrettyfier func(*runtime.Frame) (function string, file string) // contains filtered or unexported fields }
TextFormatter formats logs into text
func (*TextFormatter) Format ¶
func (f *TextFormatter) Format(entry *Entry) ([]byte, error)
Format renders a single log entry