logger

Documentation

Overview

Package log provides a log interface

Index

• func Debug(args ...interface{})
• func Debugf(template string, args ...interface{})
• func Error(args ...interface{})
• func Errorf(template string, args ...interface{})
• func Fatal(args ...interface{})
• func Fatalf(template string, args ...interface{})
• func Info(args ...interface{})
• func Infof(template string, args ...interface{})
• func Init(opts ...Option) error
• func Log(level Level, v ...interface{})
• func Logf(level Level, format string, v ...interface{})
• func NewContext(ctx context.Context, l Logger) context.Context
• func String() string
• func Trace(args ...interface{})
• func Tracef(template string, args ...interface{})
• func V(lvl Level, log Logger) bool
• func Warn(args ...interface{})
• func Warnf(template string, args ...interface{})
• type Helper
  • func Extract(ctx context.Context) *Helper
  • func NewHelper(logger Logger) *Helper
  • func (h *Helper) Debug(args ...interface{})
  • func (h *Helper) Debugf(template string, args ...interface{})
  • func (h *Helper) Error(args ...interface{})
  • func (h *Helper) Errorf(template string, args ...interface{})
  • func (h *Helper) Fatal(args ...interface{})
  • func (h *Helper) Fatalf(template string, args ...interface{})
  • func (h *Helper) Info(args ...interface{})
  • func (h *Helper) Infof(template string, args ...interface{})
  • func (h *Helper) Inject(ctx context.Context) context.Context
  • func (h *Helper) Log(level Level, args ...interface{})
  • func (h *Helper) Logf(level Level, template string, args ...interface{})
  • func (h *Helper) Trace(args ...interface{})
  • func (h *Helper) Tracef(template string, args ...interface{})
  • func (h *Helper) Warn(args ...interface{})
  • func (h *Helper) Warnf(template string, args ...interface{})
  • func (h *Helper) WithError(err error) *Helper
  • func (h *Helper) WithFields(fields map[string]interface{}) *Helper
• type Level
  • func GetLevel(levelStr string) (Level, error)
  • func (l Level) Enabled(lvl Level) bool
  • func (l Level) String() string
• type Logger
  • func Fields(fields map[string]interface{}) Logger
  • func FromContext(ctx context.Context) (Logger, bool)
  • func NewLogger(opts ...Option) Logger
• type Option
  • func SetOption(k, v interface{}) Option
  • func WithCallerSkipCount(c int) Option
  • func WithFields(fields map[string]interface{}) Option
  • func WithLevel(level Level) Option
  • func WithOutput(out io.Writer) Option
• type Options

Functions

func Debug

func Debug(args ...interface{})

func Debugf

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

func Error

func Error(args ...interface{})

func Errorf

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

func Fatal

func Fatal(args ...interface{})

func Fatalf

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

func Info

func Info(args ...interface{})

func Infof

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

func Init

func Init(opts ...Option) error

func Log

func Log(level Level, v ...interface{})

func Logf

func Logf(level Level, format string, v ...interface{})

func NewContext

func NewContext(ctx context.Context, l Logger) context.Context

func String

func String() string

func Trace

func Trace(args ...interface{})

func Tracef

func Tracef(template string, args ...interface{})

func V

func V(lvl Level, log Logger) bool

Returns true if the given level is at or lower the current logger level

func Warn

func Warn(args ...interface{})

func Warnf

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

Types

type Helper

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

func Extract

func Extract(ctx context.Context) *Helper

Extract always returns valid Helper with logger from context or with DefaultLogger as fallback. Can be used in pair with function Inject. Example: propagate RequestID to logger in service handler methods.

func NewHelper

func NewHelper(logger Logger) *Helper

func (*Helper) Debug

func (h *Helper) Debug(args ...interface{})

func (*Helper) Debugf

func (h *Helper) Debugf(template string, args ...interface{})

func (*Helper) Error

func (h *Helper) Error(args ...interface{})

func (*Helper) Errorf

func (h *Helper) Errorf(template string, args ...interface{})

func (*Helper) Fatal

func (h *Helper) Fatal(args ...interface{})

func (*Helper) Fatalf

func (h *Helper) Fatalf(template string, args ...interface{})

func (*Helper) Info

func (h *Helper) Info(args ...interface{})

func (*Helper) Infof

func (h *Helper) Infof(template string, args ...interface{})

func (*Helper) Inject

func (h *Helper) Inject(ctx context.Context) context.Context

func (*Helper) Log

func (h *Helper) Log(level Level, args ...interface{})

func (*Helper) Logf

func (h *Helper) Logf(level Level, template string, args ...interface{})

func (*Helper) Trace

func (h *Helper) Trace(args ...interface{})

func (*Helper) Tracef

func (h *Helper) Tracef(template string, args ...interface{})

func (*Helper) Warn

func (h *Helper) Warn(args ...interface{})

func (*Helper) Warnf

func (h *Helper) Warnf(template string, args ...interface{})

func (*Helper) WithError

func (h *Helper) WithError(err error) *Helper

func (*Helper) WithFields

func (h *Helper) WithFields(fields map[string]interface{}) *Helper

type Level

type Level int8

const (
	// TraceLevel level. Designates finer-grained informational events than the Debug.
	TraceLevel Level = iota - 2
	// DebugLevel level. Usually only enabled when debugging. Very verbose logging.
	DebugLevel
	// InfoLevel is the default logging priority.
	// General operational entries about what's going on inside the application.
	InfoLevel
	// WarnLevel level. Non-critical entries that deserve eyes.
	WarnLevel
	// ErrorLevel level. Logs. Used for errors that should definitely be noted.
	ErrorLevel
	// FatalLevel level. Logs and then calls `logger.Exit(1)`. highest level of severity.
	FatalLevel
)

func GetLevel

func GetLevel(levelStr string) (Level, error)

GetLevel converts a level string into a logger Level value. returns an error if the input string does not match known values.

func (Level) Enabled

func (l Level) Enabled(lvl Level) bool

Enabled returns true if the given level is at or above this level.

func (Level) String

func (l Level) String() string

type Logger

type Logger interface {
	// Init initialises options
	Init(options ...Option) error
	// The Logger options
	Options() Options
	// Fields set fields to always be logged
	Fields(fields map[string]interface{}) Logger
	// Log writes a log entry
	Log(level Level, v ...interface{})
	// Logf writes a formatted log entry
	Logf(level Level, format string, v ...interface{})
	// String returns the name of logger
	String() string
}

Logger is a generic logging interface

var (
	// Default logger
	DefaultLogger Logger = NewLogger()
)

func Fields

func Fields(fields map[string]interface{}) Logger

func FromContext

func FromContext(ctx context.Context) (Logger, bool)

func NewLogger

func NewLogger(opts ...Option) Logger

NewLogger builds a new logger based on options

type Option

type Option func(*Options)

func SetOption

func SetOption(k, v interface{}) Option

func WithCallerSkipCount

func WithCallerSkipCount(c int) Option

WithCallerSkipCount set frame count to skip

func WithFields

func WithFields(fields map[string]interface{}) Option

WithFields set default fields for the logger

func WithLevel

func WithLevel(level Level) Option

WithLevel set default level for the logger

func WithOutput

func WithOutput(out io.Writer) Option

WithOutput set default output writer for the logger

type Options

type Options struct {
	// The logging level the logger should log at. default is `InfoLevel`
	Level Level
	// fields to always be logged
	Fields map[string]interface{}
	// It's common to set this to a file, or leave it default which is `os.Stderr`
	Out io.Writer
	// Caller skip frame count for file:line info
	CallerSkipCount int
	// Alternative options
	Context context.Context
}