logging

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README

Logging Build StatusGoDoc

Logging is generally broken into two pieces: what to log and where to log it.

These values are often specified by named loggers with formatters that specify the format of log messages, a level that specifies how much to log and some sort of target to specify where to log. The fog creek logging package for Go takes a slightly different approach based on our experience with real world logging.

A default logger provides an easy path to logging. The logging package provides methods to directly log to the default logger without accessing it

logging.Info("information message")

is the same as

logging.DefaultLogger().Info("information message")

You can also use named loggers, to scope log levels to packages.

logging.GetLogger("my logger").Infof("%v", aVar)

Tags provide a way to set levels across concepts, perpendicular to logger names.

tags := ["network", "server"]
logging.DebugWithTags(tags, "tagged message")

Levels are used to filter logging. There are five levels:

  • VERBOSE
  • DEBUG
  • INFO
  • WARN
  • ERROR

By default INFO messages and above are allowed. Each logger can have a level. A method to set the default level is available, and actually sets the level on the default logger.

logging.SetDefaultLogLevel(logging.INFO)

is equivalent to

logging.DefaultLogger().SetLogLevel(logging.INFO)

Levels can also be set by tag, which overrides the loggers level. By default loggers use the default loggers level.

Loggers have a four methods for each log level, one for formatted messages, and one for just a simple array of values, plus a version of each of these with tags.

ErrorWithTagsf(tags []string, fmt string, args ...interface{})
ErrorWithTags(tags []string, args ...interface{})
Errorf(fmt string, args ...interface{})
Error(args ...interface{})

WarnWithTagsf(tags []string, fmt string, args ...interface{})
WarnWithTags(tags []string, args ...interface{})
Warnf(fmt string, args ...interface{})
Warn(args ...interface{})

InfoWithTagsf(tags []string, fmt string, args ...interface{})
InfoWithTags(tags []string, args ...interface{})
Infof(fmt string, args ...interface{})
Info(args ...interface{})

DebugWithTagsf(tags []string, fmt string, args ...interface{})
DebugWithTags(tags []string, args ...interface{})
Debugf(fmt string, args ...interface{})
Debug(args ...interface{})

VerboseWithTagsf(tags []string, fmt string, args ...interface{})
Verbosef(fmt string, args ...interface{})

Log messages are formatted by a format function. Which can be set per logger, by default loggers copy the default loggers format.

Logging ultimately goes through one or more appenders to get the messages to the console, a file or wherever. All loggers share the same appenders - but appenders can be associated with a level which is unrelated to tags.

Each logger has an optional buffer, that will be flushed whenever its level/tags change. This buffer contains un-passed messages. So that it is possible to configure the system to capture messages and replay them latter.

Replayed messages are tagged and have a double time stamp.

To use go vet with this package you can use the form:

% go tool vet -printfuncs "ErrorWithTagsf,Errorf,WarnWithTagsf,Warnf,InfoWithTagsf,Infof,DebugWithTagsf,Debugf" <package>

To use logging with your project simply:

% go get github.com/sasbury/logging

Documentation

Overview

Package logging implements tag based logging.

Logging is generally broken into two pieces: what to log and where to log it. These values are often specified by named loggers with formatters that specify the format of log messages, a level that specifies how much to log and some sort of target to specify where to log. The fog creek logging package for Go takes a slightly different approach based on our experience with real world logging.

A default logger provides an easy path to logging. The logging package provides methods to directly log ot the default logger without accessing it 

logging.Info("information message")

is the same as 

logging.DefaultLogger().Info("information message")

You can also use named loggers, to scope log levels to packages. 

logging.GetLogger("my logger").Infof("%v", aVar)

Tags provide a way to set levels across concepts, perpendicular to logger names. 

tags := ["network", "server"]
logging.DebugWithTags(tags, "tagged message")

Levels are used to filter logging. There are five levels:

  • VERBOSE
  • DEBUG
  • INFO
  • WARN
  • ERROR

By default INFO messages and above are allowed. Each logger can have a level. A method to set the default level is available, and actually sets the level on the default logger.

logging.SetDefaultLogLevel(logging.INFO)

is equivalent to

logging.DefaultLogger().SetLogLevel(logging.INFO)

Levels can also be set by tag, which overrides the loggers level. By default loggers use the default loggers level.

Loggers have a four methods for each log level, one for formatted messages, and one for just a simple array of values, plus a version of each of these with tags. 

ErrorWithTagsf(tags []string, fmt string, args ...interface{})
ErrorWithTags(tags []string, args ...interface{})
Errorf(fmt string, args ...interface{})
Error(args ...interface{})

WarnWithTagsf(tags []string, fmt string, args ...interface{})
WarnWithTags(tags []string, args ...interface{})
Warnf(fmt string, args ...interface{})
Warn(args ...interface{})

InfoWithTagsf(tags []string, fmt string, args ...interface{})
InfoWithTags(tags []string, args ...interface{})
Infof(fmt string, args ...interface{})
Info(args ...interface{})

DebugWithTagsf(tags []string, fmt string, args ...interface{})
DebugWithTags(tags []string, args ...interface{})
Debugf(fmt string, args ...interface{})
Debug(args ...interface{})

Verbose is special, since it rarely should/would be called without formatting. 

VerboseWithTagsf(tags []string, fmt string, args ...interface{})
Verbosef(fmt string, args ...interface{})

Log messages are formatted by a format function. Which can be set per logger, by default, loggers copy the default loggers format.

Logging ultimately goes through one or more appenders to get the messages to the console, a file or wherever. All loggers share the same appenders - but appenders can be associated with a level which is unrelated to tags.

Each logger has an optional buffer, that will be flushed whenever its level/tags change. This buffer contains un-passed messages. So that it is possible to configure the system to capture messages and replay them latter. Replayed messages are tagged and have a double time stamp.

To use go vet with this package you can use the form:

go tool vet -printfuncs "ErrorWithTagsf,Errorf,WarnWithTagsf,Warnf,InfoWithTagsf,Infof,DebugWithTagsf,Debugf" <package>

Package logging for Go takes a slightly different approach based on our experience with real world logging.

A default logger provides an easy path to logging. Named loggers provide a way to set levels by package. Tags provide a way to set levels across concepts, perpendicular to logger names. Default log levels and default tag levels are independent of the default logger. All loggers share the same appenders - but appenders can be associated with a level which is unrelated to tags. Each logger has an optional buffer, that will be flushd whenever its level/tags change. This buffer contains un-passed messages. So that it is possible to configure the system to capture messages and replay them later. Replayed messages are tagged and have a double time stamp. A default appender is initialized to send log messages to stderr.

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func AdaptStandardLogging 

func AdaptStandardLogging(level LogLevel, tags []string)

AdaptStandardLogging points the standard logging to fog creek logging using the provided level and tags. The default will be info with no tags.

func AddAppender 

func AddAppender(appender LogAppender)

AddAppender adds a new global appender for use by all loggers. Levels can be used to restrict logging to specific appenders.

func AddTag 

func AddTag(tags []string, newTag string) []string

AddTag creates a new array and adds a string to it. This insures that no slices are shared for tags.

func CaptureLoggingErrors 

func CaptureLoggingErrors(errs chan<- error)

CaptureLoggingErrors allows the logging user to provide a channel for capturing logging errors. Any error during the logging process, like an appender failing will be sent to this channel. By default there is no error channel. Logging will not block when writting to the error channel so make sure the channel is big enough to capture errors

func CheckLevel 

func CheckLevel(l LogLevel, tags []string) bool

CheckLevel tests the default logger for its permissions

func ClearAppenders 

func ClearAppenders()

ClearAppenders removes all of the global appenders, mainly used during configuration. Will pause and restart logging

func ClearLoggers 

func ClearLoggers()

ClearLoggers is provided so that an application can completely reset its logging configuration, for example on a SIGHUP

func Debug 

func Debug(args ...interface{})

Debug logs an DEBUG level message with no tags and provided arguments joined into a string. Uses the default logger.

func DebugWithTags 

func DebugWithTags(tags []string, args ...interface{})

DebugWithTags logs an DEBUG level message with the provided tags and provided arguments joined into a string. Uses the default logger.

func DebugWithTagsf 

func DebugWithTagsf(tags []string, fmt string, args ...interface{})

DebugWithTagsf logs an DEBUG level message with the provided tags and formatted string. Uses the default logger.

func Debugf 

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

Debugf logs an DEBUG level message with the no tags and formatted string. Uses the default logger.

func DisableVerboseLogging 

func DisableVerboseLogging()

DisableVerboseLogging by default verbose logging is ignored, use this method to turn off verbose logging if you have enabled it

func EnableVerboseLogging 

func EnableVerboseLogging()

EnableVerboseLogging by default verbose logging is ignored, use this method to allow verbose logging

func Error 

func Error(args ...interface{})

Error logs an ERROR level message with no tags and provided arguments joined into a string. Uses the default logger.

func ErrorWithTags 

func ErrorWithTags(tags []string, args ...interface{})

ErrorWithTags logs an ERROR level message with the provided tags and provided arguments joined into a string. Uses the default logger.

func ErrorWithTagsf 

func ErrorWithTagsf(tags []string, fmt string, args ...interface{})

ErrorWithTagsf logs an ERROR level message with the provided tags and formatted string. Uses the default logger.

func Errorf 

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

Errorf logs an ERROR level message with the no tags and formatted string. Uses the default logger.

func Info 

func Info(args ...interface{})

Info logs an INFO level message with no tags and provided arguments joined into a string. Uses the default logger.

func InfoWithTags 

func InfoWithTags(tags []string, args ...interface{})

InfoWithTags logs an INFO level message with the provided tags and provided arguments joined into a string. Uses the default logger.

func InfoWithTagsf 

func InfoWithTagsf(tags []string, fmt string, args ...interface{})

InfoWithTagsf logs an INFO level message with the provided tags and formatted string. Uses the default logger.

func Infof 

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

Infof logs an INFO level message with the no tags and formatted string. Uses the default logger.

func PauseLogging 

func PauseLogging()

PauseLogging stops all logging from being processed. Pause will not wait for all log messages to be processed

func RestartLogging 

func RestartLogging()

RestartLogging starts messages logging again

func SetDefaultBufferLength 

func SetDefaultBufferLength(length int)

SetDefaultBufferLength sets the buffer length for the default logger, new loggers will use this length. Existing loggers with buffers are not affected, those with buffers are not effected.

func SetDefaultFormatter 

func SetDefaultFormatter(formatter LogFormatter)

SetDefaultFormatter sets the default formatter used by appenders that don't have their own

func SetDefaultLogLevel 

func SetDefaultLogLevel(l LogLevel)

SetDefaultLogLevel sets the default loggers log level, flushes all buffers in case messages are cleared for logging

func SetDefaultTagLogLevel 

func SetDefaultTagLogLevel(tag string, l LogLevel)

SetDefaultTagLogLevel sets the default loggers level for the specified tag, flushes all buffers in case messages are cleared for logging..

func StopLogging 

func StopLogging()

StopLogging can only be called once, and completely stops the logging process

func VerboseWithTagsf 

func VerboseWithTagsf(tags []string, fmt string, args ...interface{})

VerboseWithTagsf logs an VERBOSE level message with the provided tags and formatted string. Uses the default logger. Verbose messages are not buffered

func Verbosef 

func Verbosef(fmt string, args ...interface{})

Verbosef logs an VERBOSE level message with the no tags and formatted string. Uses the default logger. Verbose messages are not buffered

func WaitForIncoming 

func WaitForIncoming()

WaitForIncoming should be used in tests or system shutdowns to make sure that all of the log messages pushed into the logging channel are processed and appended appropriately.

func Warn 

func Warn(args ...interface{})

Warn logs an WARN level message with no tags and provided arguments joined into a string. Uses the default logger.

func WarnWithTags 

func WarnWithTags(tags []string, args ...interface{})

WarnWithTags logs an WARN level message with the provided tags and provided arguments joined into a string. Uses the default logger.

func WarnWithTagsf 

func WarnWithTagsf(tags []string, fmt string, args ...interface{})

WarnWithTagsf logs an WARN level message with the provided tags and formatted string. Uses the default logger.

func Warnf 

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

Warnf logs an WARN level message with the no tags and formatted string. Uses the default logger.

Types

type BaseLogAppender 

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

BaseLogAppender provides a simple struct for building log appenders.

func (*BaseLogAppender) CheckLevel 

func (appender *BaseLogAppender) CheckLevel(l LogLevel) bool

CheckLevel tests the level in the BaseLogAppender struct

func (*BaseLogAppender) SetFormatter 

func (appender *BaseLogAppender) SetFormatter(formatter LogFormatter)

SetFormatter stores the formatting function in the BaseLogAppender struct

func (*BaseLogAppender) SetLevel 

func (appender *BaseLogAppender) SetLevel(l LogLevel)

SetLevel stores the level in the BaseLogAppender struct

type ClosableAppender 

type ClosableAppender interface {
	LogAppender
	io.Closer
}

ClosableAppender defines an optional single method for appenders that need to be closed when they will not be used anymore. An example is a file appender.

type ConsoleAppender 

type ConsoleAppender struct {
	BaseLogAppender
	// contains filtered or unexported fields
}

ConsoleAppender can be used to write log records to standard err or standard out.

func NewStdErrAppender 

func NewStdErrAppender() *ConsoleAppender

NewStdErrAppender creates a console appender configured to write to standard err.

func NewStdOutAppender 

func NewStdOutAppender() *ConsoleAppender

NewStdOutAppender creates a console appender configured to write to standard out.

func (*ConsoleAppender) Log 

func (appender *ConsoleAppender) Log(record *LogRecord) error

Log writes the record, if its level passes the appenders level to stderr or stdout

type ErrorAppender 

type ErrorAppender struct {
	NullAppender
}

ErrorAppender is provided for testing and will generate an error when asked to log a message, it will also maintain a count

func NewErrorAppender 

func NewErrorAppender() *ErrorAppender

NewErrorAppender creates an ErrorAppender

func (*ErrorAppender) Log 

func (appender *ErrorAppender) Log(record *LogRecord) error

Log adds to the count and returns an error

type LogAppender 

type LogAppender interface {
	//Log takes a record and should append it
	Log(record *LogRecord) error
	//SetLevel should remember the level assigned to this appender and check
	//it to filter incoming records
	SetLevel(l LogLevel)
	//SetFormatter should remember the formatting function that this
	//appender should use to generate strings from LogRecords
	SetFormatter(formatter LogFormatter)
}

LogAppender is used to push log records to a destination like a file

type LogFormat 

type LogFormat string

LogFormat is the name of a known formatting function. 

const FULL LogFormat = "full"

FULL formats messages with the date to ms accuracy, the level, tags and message. Replayed messages have a special field added. 

const MINIMAL LogFormat = "minimal"

MINIMAL describes a formatter that just prints the message, replays are not indicated 

const MINIMALTAGGED LogFormat = "minimaltagged"

MINIMALTAGGED describes a formatter that just prints the level, tags and message, replays are not indicated 

const SIMPLE LogFormat = "simple"

SIMPLE describes a formatter that just prints the date, level and message, replays are not indicated

func FormatFromString 

func FormatFromString(formatName string) LogFormat

FormatFromString converts a string name to a LogFormat. Valid arguemnts include full, simple, minimaltagged and minimal. An unknown string will be treated like simple.

type LogFormatter 

type LogFormatter func(level LogLevel, tags []string, message string, t time.Time, original time.Time) string

LogFormatter is a function type used to convert a log record into a string. Original time is provided times when the formatter has to construct a replayed message from the buffer

func GetFormatter 

func GetFormatter(formatName LogFormat) LogFormatter

GetFormatter returns the function associated with a named format.

type LogLevel 

type LogLevel uint8

LogLevel is the type used to indicate the importance of a logging request 

const (
	//DEFAULT is the default log level, loggers with default level will use the default loggers level
	DEFAULT LogLevel = iota
	//VERBOSE is the wordiest log level, useful for very big text output that may
	//be the last result during testing or debugging
	VERBOSE
	//DEBUG is generally the lowest level used when testing
	DEBUG
	//INFO is used for generally helpful but not important messages
	INFO
	//WARN is provided for warnings that do not represent a major program error
	WARN
	//ERROR is the highest log level and should only be used for exceptional conditions
	ERROR
)

func LevelFromString 

func LevelFromString(str string) LogLevel

LevelFromString converts a level in any case to a LogLevel, valid values are error, warning, warn, info, informative, debug and verbose.

func (LogLevel) String 

func (level LogLevel) String() string

String converts a log level to an upper case string

type LogRecord 

type LogRecord struct {
	//Time is the time that the log record is being appended, can be
	//different from Original if the record was buffered
	Time time.Time
	//Original is the original time for the log record
	Original time.Time
	//Level is the level the record was logged at
	Level LogLevel
	//Tags are the custom tags assigned to the record when it was logged
	Tags []string
	//Message is the actual log message
	Message string
	//Logger is the logger associated with this log record, if any
	Logger *LoggerImpl
}

LogRecord is the type used in the logging buffer

func NewLogRecord 

func NewLogRecord(logger *LoggerImpl, level LogLevel, tags []string, message string, time time.Time, original time.Time) *LogRecord

NewLogRecord creates a log record object

type Logger 

type Logger interface {
	ErrorWithTagsf(tags []string, fmt string, args ...interface{})
	ErrorWithTags(tags []string, args ...interface{})
	Errorf(fmt string, args ...interface{})
	Error(args ...interface{})

	WarnWithTagsf(tags []string, fmt string, args ...interface{})
	WarnWithTags(tags []string, args ...interface{})
	Warnf(fmt string, args ...interface{})
	Warn(args ...interface{})

	InfoWithTagsf(tags []string, fmt string, args ...interface{})
	InfoWithTags(tags []string, args ...interface{})
	Infof(fmt string, args ...interface{})
	Info(args ...interface{})

	DebugWithTagsf(tags []string, fmt string, args ...interface{})
	DebugWithTags(tags []string, args ...interface{})
	Debugf(fmt string, args ...interface{})
	Debug(args ...interface{})

	VerboseWithTagsf(tags []string, fmt string, args ...interface{})
	Verbosef(fmt string, args ...interface{})

	SetLogLevel(l LogLevel)
	SetTagLevel(tag string, l LogLevel)
	CheckLevel(l LogLevel, tags []string) bool

	SetBufferLength(length int)
}

Logger is the interface for the objects that are the target of logging messages. Logging methods imply a level. For example, Info() implies a level of LogLevel.INFO.

func DefaultLogger 

func DefaultLogger() Logger

DefaultLogger returns a logger that can be used when a named logger isn't required

func GetLogger 

func GetLogger(name string) Logger

GetLogger returns a named logger, creating it if necessary. The logger will have the default settings. By default the logger will use the DefaultLoggers level and tag levels

type LoggerImpl 

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

LoggerImpl stores the data for a logger. A Logger maintains its own level, tag levels and buffer. Each logger is named.

func (*LoggerImpl) CheckLevel 

func (logger *LoggerImpl) CheckLevel(l LogLevel, tags []string) bool

CheckLevel checks tags, then check the level on this , or the default level

func (*LoggerImpl) Debug 

func (logger *LoggerImpl) Debug(args ...interface{})

Debug logs an DEBUG level message with no tags and provided arguments joined into a string.

func (*LoggerImpl) DebugWithTags 

func (logger *LoggerImpl) DebugWithTags(tags []string, args ...interface{})

DebugWithTags logs an DEBUG level message with the provided tags and provided arguments joined into a string.

func (*LoggerImpl) DebugWithTagsf 

func (logger *LoggerImpl) DebugWithTagsf(tags []string, fmt string, args ...interface{})

DebugWithTagsf logs an DEBUG level message with the provided tags and formatted string.

func (*LoggerImpl) Debugf 

func (logger *LoggerImpl) Debugf(fmt string, args ...interface{})

Debugf logs an DEBUG level message with the no tags and formatted string.

func (*LoggerImpl) Error 

func (logger *LoggerImpl) Error(args ...interface{})

Error logs an ERROR level message with no tags and provided arguments joined into a string.

func (*LoggerImpl) ErrorWithTags 

func (logger *LoggerImpl) ErrorWithTags(tags []string, args ...interface{})

ErrorWithTags logs an ERROR level message with the provided tags and provided arguments joined into a string.

func (*LoggerImpl) ErrorWithTagsf 

func (logger *LoggerImpl) ErrorWithTagsf(tags []string, fmt string, args ...interface{})

ErrorWithTagsf logs an ERROR level message with the provided tags and formatted string.

func (*LoggerImpl) Errorf 

func (logger *LoggerImpl) Errorf(fmt string, args ...interface{})

Errorf logs an ERROR level message with the no tags and formatted string.

func (*LoggerImpl) Info 

func (logger *LoggerImpl) Info(args ...interface{})

Info logs an INFO level message with no tags and provided arguments joined into a string.

func (*LoggerImpl) InfoWithTags 

func (logger *LoggerImpl) InfoWithTags(tags []string, args ...interface{})

InfoWithTags logs an INFO level message with the provided tags and provided arguments joined into a string.

func (*LoggerImpl) InfoWithTagsf 

func (logger *LoggerImpl) InfoWithTagsf(tags []string, fmt string, args ...interface{})

InfoWithTagsf logs an INFO level message with the provided tags and formatted string.

func (*LoggerImpl) Infof 

func (logger *LoggerImpl) Infof(fmt string, args ...interface{})

Infof logs an INFO level message with the no tags and formatted string.

func (*LoggerImpl) SetBufferLength 

func (logger *LoggerImpl) SetBufferLength(length int)

SetBufferLength clears the buffer and creates a new one of the specified length.

func (*LoggerImpl) SetLogLevel 

func (logger *LoggerImpl) SetLogLevel(l LogLevel)

SetLogLevel sets the level of messages allowed for a logger. This level can be overriden for specific tags using SetTagLevel. Changing the level for a Logger flushes its buffer in case messages are now free to be logged. This means that buffered messages might be printed out of order, but will be formatted to indicate this.

func (*LoggerImpl) SetTagLevel 

func (logger *LoggerImpl) SetTagLevel(tag string, l LogLevel)

SetTagLevel assigns a log level to a specific tag. This level can override the general level for a logger allowing specific log messages to slip through and be appended to the logs

func (*LoggerImpl) VerboseWithTagsf 

func (logger *LoggerImpl) VerboseWithTagsf(tags []string, fmt string, args ...interface{})

VerboseWithTagsf logs an VERBOSE level message with the provided tags and formatted string. Verbose messages are not buffered

func (*LoggerImpl) Verbosef 

func (logger *LoggerImpl) Verbosef(fmt string, args ...interface{})

Verbosef logs an VERBOSE level message with the no tags and formatted string. Verbose messages are not buffered

func (*LoggerImpl) Warn 

func (logger *LoggerImpl) Warn(args ...interface{})

Warn logs an WARN level message with no tags and provided arguments joined into a string.

func (*LoggerImpl) WarnWithTags 

func (logger *LoggerImpl) WarnWithTags(tags []string, args ...interface{})

WarnWithTags logs an WARN level message with the provided tags and provided arguments joined into a string.

func (*LoggerImpl) WarnWithTagsf 

func (logger *LoggerImpl) WarnWithTagsf(tags []string, fmt string, args ...interface{})

WarnWithTagsf logs an WARN level message with the provided tags and formatted string.

func (*LoggerImpl) Warnf 

func (logger *LoggerImpl) Warnf(fmt string, args ...interface{})

Warnf logs an WARN level message with the no tags and formatted string.

type MemoryAppender 

type MemoryAppender struct {
	BaseLogAppender
	//LoggedMesssages is the list of messages that have been logged to this appender
	LoggedMessages []string
}

MemoryAppender is useful for testing and keeps a list of logged messages

func NewMemoryAppender 

func NewMemoryAppender() *MemoryAppender

NewMemoryAppender creates a new empty memory appender

func (*MemoryAppender) GetLoggedMessages 

func (appender *MemoryAppender) GetLoggedMessages() []string

GetLoggedMessages returns the list of logged messages as strings.

func (*MemoryAppender) Log 

func (appender *MemoryAppender) Log(record *LogRecord) error

Log checks the log records level and if it passes appends the record to the list

type NullAppender 

type NullAppender struct {
	BaseLogAppender
	// contains filtered or unexported fields
}

NullAppender is a simple log appender that just counts the number of log messages

func NewNullAppender 

func NewNullAppender() *NullAppender

NewNullAppender creates a null appender

func (*NullAppender) Count 

func (appender *NullAppender) Count() int64

Count returns the count of messages logged

func (*NullAppender) Log 

func (appender *NullAppender) Log(record *LogRecord) error

Log adds 1 to the count

type RollingFileAppender 

type RollingFileAppender struct {
	BaseLogAppender
	// contains filtered or unexported fields
}

RollingFileAppender is the wrapper for a rolling file log appender.

A RollingFile appender will log to a file specified by prefix, which can contain a path, and a suffix, like "log". The appender will concatenate the prefix and suffix using the following format "prefix.#.suffix" where # is the log file number. The current file will be "prefix.suffix". Note, the . between the elements, the prefix and suffix should not include these.

Files can be rolled on size or manually by calling Roll().

The maxFiles must be at least 1 MaxFileSize must be at least 1024 - and is measured in bytes, if the max files is 1 the max file size is ignored

The actual file size will exceed maxFileSize, because the roller will not roll until a log message pushes the file past the size.

func NewRollingFileAppender 

func NewRollingFileAppender(prefix string, suffix string, maxFileSize int64, maxFiles int16) *RollingFileAppender

NewRollingFileAppender is used to create a rolling file appender

func (*RollingFileAppender) Close 

func (appender *RollingFileAppender) Close() error

Close closes the current file after flushing any buffered data

func (*RollingFileAppender) Log 

func (appender *RollingFileAppender) Log(record *LogRecord) error

Log a record to the current file

func (*RollingFileAppender) Roll 

func (appender *RollingFileAppender) Roll() error

Roll moves the file to the next number, up to the max files.

type SysLogAppender 

type SysLogAppender struct {
	BaseLogAppender
	// contains filtered or unexported fields
}

SysLogAppender is the logging appender for appending to the syslog service

func NewSysLogAppender 

func NewSysLogAppender() *SysLogAppender

NewSysLogAppender creates a sys log appender

func (*SysLogAppender) Close 

func (appender *SysLogAppender) Close() error

Close shuts down the syslog connection

func (*SysLogAppender) Log 

func (appender *SysLogAppender) Log(record *LogRecord) error

Log adds a record to the sys log

type WriterAppender 

type WriterAppender struct {
	BaseLogAppender
	// contains filtered or unexported fields
}

WriterAppender is a simple appender that pushes messages as bytes to a writer

func NewWriterAppender 

func NewWriterAppender(writer io.Writer) *WriterAppender

NewWriterAppender creates an appender from the specified writer.

func (*WriterAppender) Log 

func (appender *WriterAppender) Log(record *LogRecord) error

Log checks the log record's level and then writes the formatted record to the writer, followed by the bytes for "\n"

Source Files

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