log

Documentation

Index

• type Builder
• type ContextExtractor
• type Fields
• type Level
  • func ParseLevel(str string) Level
  • func (l Level) String() string
• type Logger
• type LoggerConfiguration
• type Messages

Types

type Builder

type Builder interface {
	// IncrementSkipFrames **peels** an additional layer(s) to show the actual log line position.
	//
	// **Note**
	//
	// This one is really important, the implementation must increment and not override
	// the value of skip frames.
	//
	// One should take into account only it's own frame stack, bricks will add 2 on top.
	IncrementSkipFrames(addition int) Builder
	// Set system log level
	//
	// Optional:
	//	Logger Implementation should have a default log level. This allows filtering log lines with level below default one.
	SetLevel(level Level) Builder
	// Build() returns a Logger implementation, always
	Build() Logger
}

Builder defines log configuration options

type ContextExtractor

type ContextExtractor func(ctx context.Context) map[string]interface{}

ContextExtractor is an alias for a function that extract values from context Make sure that this function returns fast and is "thread safe"

type Fields

type Fields interface {
	Messages
	// Add an error to the log structure, output depends on the implementation
	WithError(err error) Fields
	// Add an informative field to the log structure, output depends on the implementation
	//
	// Avoid using the following names:
	// 		time, message, error, caller, stack
	WithField(name string, value interface{}) Fields
}

Fields part of the Logger interface

type Level

type Level int8

Level is a log level enum

const (
	// TraceLevel defines trace log level.
	TraceLevel Level = iota
	// DebugLevel defines debug log level.
	DebugLevel
	// InfoLevel defines info log level.
	InfoLevel
	// WarnLevel defines warn log level.
	WarnLevel
	// ErrorLevel defines error log level.
	ErrorLevel
)

func ParseLevel

func ParseLevel(str string) Level

ParseLevel tries to parse level from string, if unable to parse a Trace level will be returned as a default

func (Level) String

func (l Level) String() string

type Logger

type Logger interface {
	Fields
	// Implementor returns the actual lib/struct that is responsible for the above logic
	Configuration() LoggerConfiguration
}

Logger is a simple interface that defines logging in the system

type LoggerConfiguration

type LoggerConfiguration interface {
	Level() Level
	Implementation() interface{}
}

LoggerConfiguration get some of the logger configuration options and also the implementation

type Messages

type Messages interface {
	// Highly detailed tracing messages. Produces the most voluminous output. Used by developers for developers
	// Some implementations doesn't have that granularity and use Debug level instead
	//
	// Note:
	// 	ctx can be nil
	Trace(ctx context.Context, format string, args ...interface{})
	// Relatively detailed tracing messages. Used mostly by developers to debug the flow
	//
	// Note:
	// 	ctx can be nil
	Debug(ctx context.Context, format string, args ...interface{})
	// Informational messages that might make sense to users unfamiliar with this application
	//
	// Note:
	// 	ctx can be nil
	Info(ctx context.Context, format string, args ...interface{})
	// Potentially harmful situations of interest to users that indicate potential problems.
	//
	// Note:
	// 	ctx can be nil
	Warn(ctx context.Context, format string, args ...interface{})
	// Very severe error events that might cause the application to terminate or misbehave.
	// It's not intended to use to log every 'error', for that use 'WithError(err).<Trace|Debug|Info|...>(...)'
	//
	// Note:
	// 	ctx can be nil
	Error(ctx context.Context, format string, args ...interface{})
	// Custom is a Convenience function that will enable you to set log level dynamically
	//  and perhaps skip additional frames.
	//
	// Note:
	// 	ctx can be nil
	Custom(ctx context.Context, level Level, skipAdditionalFrames int, format string, args ...interface{})
}

Messages part of the Logger interface