logger

Documentation

Index

• Constants
• type Level
  • func (lvl Level) Less(other Level) bool
  • func (lvl Level) String() string
• type Logger
  • func New(printer Printer) *Logger
  • func (l *Logger) Debug(v ...interface{})
  • func (l *Logger) Error(v ...interface{})
  • func (l *Logger) Info(v ...interface{})
  • func (l *Logger) SetLevel(level Level)
  • func (l *Logger) SetPrefix(prefix string)
  • func (l *Logger) Warn(v ...interface{})
• type Printer

Constants

const DefaultPrefix = "instana: "

DefaultPrefix is the default log prefix used by Logger

Types

type Level

type Level uint8

Level defines the minimum logging level for logger.Log

const (
	ErrorLevel Level = iota
	WarnLevel
	InfoLevel
	DebugLevel
)

Valid log levels to be used with (*logger.Logger).SetLevel()

func (Level) Less

func (lvl Level) Less(other Level) bool

Less returns whether the log level is less than the given one in logical order: ErrorLevel > WarnLevel > InfoLevel > DebugLevel

func (Level) String

func (lvl Level) String() string

String returns the log line label for this level

type Logger

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

Logger is a configurable leveled logger used by Instana's Go sensor. It follows the same interface as github.com/sirupsen/logrus.Logger and go.uber.org/zap.SugaredLogger

func New

func New(printer Printer) *Logger

New initializes a new instance of Logger that uses provided printer as a backend to output the log messages. The stdlib log.Logger satisfies logger.Printer interface:

logger := logger.New(logger.WarnLevel, log.New(os.Stderr, "instana:", log.LstdFlags))
logger.SetLevel(logger.WarnLevel)

logger.Debug("this is a debug message") // won't be printed
logger.Error("this is an  message") // ... while this one will

In case there is no printer provided, logger.Logger will use a new instance of log.Logger initialized with log.Lstdflags that writes to os.Stderr:

log.New(os.Stderr, "", log.Lstdflags)

The default logging level for a new logger instance is logger.ErrorLevel.

func (*Logger) Debug

func (l *Logger) Debug(v ...interface{})

Debug appends a debug message to the log

func (*Logger) Error

func (l *Logger) Error(v ...interface{})

Error appends an error message to the log

func (*Logger) Info

func (l *Logger) Info(v ...interface{})

Info appends an info message to the log

func (*Logger) SetLevel

func (l *Logger) SetLevel(level Level)

SetLevel changes the log level for this logger instance. In case there is an INSTANA_DEBUG env variable set, the provided log level will be overridden with DebugLevel.

func (*Logger) SetPrefix

func (l *Logger) SetPrefix(prefix string)

SetPrefix sets the label that will be used as a prefix for each log line

func (*Logger) Warn

func (l *Logger) Warn(v ...interface{})

Warn appends a warning message to the log

type Printer

type Printer interface {
	Print(a ...interface{})
}

Printer is used by logger.Log instance to print out a log message