Documentation ¶
Index ¶
- Constants
- Variables
- func WithContext(ctx context.Context, logger Logger, args ...interface{}) context.Context
- type Binary
- type CapturedStacktrace
- type ColorOption
- type ExcludeByMessage
- type ExcludeByPrefix
- type ExcludeByRegexp
- type ExcludeFuncs
- type Flushable
- type Format
- type Hex
- type InterceptLogger
- type Level
- type LevelWriter
- type LeveledWriter
- type Locker
- type Logger
- type LoggerOptions
- type NoopLocker
- type Octal
- type OutputResettable
- type SinkAdapter
- type StandardLoggerOptions
Constants ¶
const MissingKey = "EXTRA_VALUE_AT_END"
const TimeFormat = "2006-01-02T15:04:05.000Z0700"
TimeFormat to use for logging. This is a version of RFC3339 that contains contains millisecond precision
Variables ¶
var ( //DefaultOutput is used as the default log output. DefaultOutput io.Writer = os.Stderr // DefaultLevel is used as the default log level. DefaultLevel = Info )
var ( // DefaultOptions is used to create the Default logger. These are read // only when the Default logger is created, so set them as soon as the // process starts. DefaultOptions = &LoggerOptions{ Level: DefaultLevel, Output: DefaultOutput, } )
Functions ¶
func WithContext ¶
WithContext inserts a logger into the context and is retrievable with FromContext. The optional args can be set with the same syntax as Logger.With to set fields on the inserted logger. This will not modify the logger argument in-place.
Types ¶
type Binary ¶
type Binary int
A simple shortcut to format numbers in binary when displayed with the normal text output. For example: L.Info("bits", Binary(17))
type CapturedStacktrace ¶
type CapturedStacktrace string
CapturedStacktrace represents a stacktrace captured by a previous call to log.Stacktrace. If passed to a logging function, the stacktrace will be appended.
func Stacktrace ¶
func Stacktrace() CapturedStacktrace
Stacktrace captures a stacktrace of the current goroutine and returns it to be passed to a logging function.
type ColorOption ¶
type ColorOption uint8
ColorOption expresses how the output should be colored, if at all.
const ( // ColorOff is the default coloration, and does not // inject color codes into the io.Writer. ColorOff ColorOption = iota // AutoColor checks if the io.Writer is a tty, // and if so enables coloring. AutoColor // ForceColor will enable coloring, regardless of whether // the io.Writer is a tty or not. ForceColor )
type ExcludeByMessage ¶
type ExcludeByMessage struct {
// contains filtered or unexported fields
}
ExcludeByMessage provides a simple way to build a list of log messages that can be queried and matched. This is meant to be used with the Exclude option on Options to suppress log messages. This does not hold any mutexs within itself, so normal usage would be to Add entries at setup and none after Exclude is going to be called. Exclude is called with a mutex held within the Logger, so that doesn't need to use a mutex. Example usage:
f := new(ExcludeByMessage) f.Add("Noisy log message text") appLogger.Exclude = f.Exclude
func (*ExcludeByMessage) Add ¶
func (f *ExcludeByMessage) Add(msg string)
Add a message to be filtered. Do not call this after Exclude is to be called due to concurrency issues.
type ExcludeByPrefix ¶
type ExcludeByPrefix string
ExcludeByPrefix is a simple type to match a message string that has a common prefix.
type ExcludeByRegexp ¶
ExcludeByRegexp takes a regexp and uses it to match a log message string. If it matches the log entry is excluded.
type ExcludeFuncs ¶
ExcludeFuncs is a slice of functions that will called to see if a log entry should be filtered or not. It stops calling functions once at least one returns true.
type Flushable ¶
type Flushable interface {
Flush() error
}
Flushable represents a method for flushing an output buffer. It can be used if Resetting the log to use a new output, in order to flush the writes to the existing output beforehand.
type Format ¶
type Format []interface{}
Format is a simple convience type for when formatting is required. When processing a value of this type, the logger automatically treats the first argument as a Printf formatting string and passes the rest as the values to be formatted. For example: L.Info(Fmt{"%d beans/day", beans}).
type Hex ¶
type Hex int
A simple shortcut to format numbers in hex when displayed with the normal text output. For example: L.Info("header value", Hex(17))
type InterceptLogger ¶
type InterceptLogger interface { // Logger is the root logger for an InterceptLogger Logger // RegisterSink adds a SinkAdapter to the InterceptLogger RegisterSink(sink SinkAdapter) // DeregisterSink removes a SinkAdapter from the InterceptLogger DeregisterSink(sink SinkAdapter) // Create a interceptlogger that will prepend the name string on the front of all messages. // If the logger already has a name, the new value will be appended to the current // name. That way, a major subsystem can use this to decorate all it's own logs // without losing context. NamedIntercept(name string) InterceptLogger // Create a interceptlogger that will prepend the name string on the front of all messages. // This sets the name of the logger to the value directly, unlike Named which honor // the current name as well. ResetNamedIntercept(name string) InterceptLogger // Deprecated: use StandardLogger StandardLoggerIntercept(opts *StandardLoggerOptions) *log.Logger // Deprecated: use StandardWriter StandardWriterIntercept(opts *StandardLoggerOptions) io.Writer }
InterceptLogger describes the interface for using a logger that can register different output sinks. This is useful for sending lower level log messages to a different output while keeping the root logger at a higher one.
func NewInterceptLogger ¶
func NewInterceptLogger(opts *LoggerOptions) InterceptLogger
type Level ¶
type Level int32
Level represents a log level.
const ( // NoLevel is a special level used to indicate that no level has been // set and allow for a default to be used. NoLevel Level = 0 // Trace is the most verbose level. Intended to be used for the tracing // of actions in code, such as function enters/exits, etc. Trace Level = 1 // Debug information for programmer lowlevel analysis. Debug Level = 2 // Info information about steady state operations. Info Level = 3 // Warn information about rare but handled events. Warn Level = 4 // Error information about unrecoverable events. Error Level = 5 // Off disables all logging output. Off Level = 6 )
func LevelFromString ¶
LevelFromString returns a Level type for the named log level, or "NoLevel" if the level string is invalid. This facilitates setting the log level via config or environment variable by name in a predictable way.
type LevelWriter ¶
LevelWriter is the interface that wraps the LevelWrite method.
type LeveledWriter ¶
type LeveledWriter struct {
// contains filtered or unexported fields
}
LeveledWriter writes all log messages to the standard writer, except for log levels that are defined in the overrides map.
func NewLeveledWriter ¶
NewLeveledWriter returns an initialized LeveledWriter.
standard will be used as the default writer for all log levels, except for log levels that are defined in the overrides map.
func (*LeveledWriter) LevelWrite ¶
func (lw *LeveledWriter) LevelWrite(level Level, p []byte) (int, error)
LevelWrite implements LevelWriter.
type Locker ¶
type Locker interface { // Lock is called when the output is going to be changed or written to Lock() // Unlock is called when the operation that called Lock() completes Unlock() }
Locker is used for locking output. If not set when creating a logger, a sync.Mutex will be used internally.
type Logger ¶
type Logger interface { // Args are alternating key, val pairs // keys must be strings // vals can be any type, but display is implementation specific // Emit a message and key/value pairs at a provided log level Log(level Level, msg string, args ...interface{}) // Emit a message and key/value pairs at the TRACE level Trace(msg string, args ...interface{}) // Emit a message and key/value pairs at the DEBUG level Debug(msg string, args ...interface{}) // Emit a message and key/value pairs at the INFO level Info(msg string, args ...interface{}) // Emit a message and key/value pairs at the WARN level Warn(msg string, args ...interface{}) // Emit a message and key/value pairs at the ERROR level Error(msg string, args ...interface{}) // Indicate if TRACE logs would be emitted. This and the other Is* guards // are used to elide expensive logging code based on the current level. IsTrace() bool // Indicate if DEBUG logs would be emitted. This and the other Is* guards IsDebug() bool // Indicate if INFO logs would be emitted. This and the other Is* guards IsInfo() bool // Indicate if WARN logs would be emitted. This and the other Is* guards IsWarn() bool // Indicate if ERROR logs would be emitted. This and the other Is* guards IsError() bool // ImpliedArgs returns With key/value pairs ImpliedArgs() []interface{} // Creates a sublogger that will always have the given key/value pairs With(args ...interface{}) Logger // Returns the Name of the logger Name() string // Create a logger that will prepend the name string on the front of all messages. // If the logger already has a name, the new value will be appended to the current // name. That way, a major subsystem can use this to decorate all it's own logs // without losing context. Named(name string) Logger // Create a logger that will prepend the name string on the front of all messages. // This sets the name of the logger to the value directly, unlike Named which honor // the current name as well. ResetNamed(name string) Logger // Updates the level. This should affect all related loggers as well, // unless they were created with IndependentLevels. If an // implementation cannot update the level on the fly, it should no-op. SetLevel(level Level) // Return a value that conforms to the stdlib log.Logger interface StandardLogger(opts *StandardLoggerOptions) *log.Logger // Return a value that conforms to io.Writer, which can be passed into log.SetOutput() StandardWriter(opts *StandardLoggerOptions) io.Writer }
Logger describes the interface that must be implemeted by all loggers.
func Default ¶
func Default() Logger
Default returns a globally held logger. This can be a good starting place, and then you can use .With() and .Name() to create sub-loggers to be used in more specific contexts. The value of the Default logger can be set via SetDefault() or by changing the options in DefaultOptions.
This method is goroutine safe, returning a global from memory, but cause should be used if SetDefault() is called it random times in the program as that may result in race conditions and an unexpected Logger being returned.
func FromContext ¶
FromContext returns a logger from the context. This will return L() (the default logger) if no logger is found in the context. Therefore, this will never return a nil value.
func FromStandardLogger ¶
func FromStandardLogger(l *log.Logger, opts *LoggerOptions) Logger
Takes a standard library logger and returns a Logger that will write to it
func NewNullLogger ¶
func NewNullLogger() Logger
NewNullLogger instantiates a Logger for which all calls will succeed without doing anything. Useful for testing purposes.
func SetDefault ¶
SetDefault changes the logger to be returned by Default()and L() to the one given. This allows packages to use the default logger and have higher level packages change it to match the execution environment. It returns any old default if there is one.
NOTE: This is expected to be called early in the program to setup a default logger. As such, it does not attempt to make itself not racy with regard to the value of the default logger. Ergo if it is called in goroutines, you may experience race conditions with other goroutines retrieving the default logger. Basically, don't do that.
type LoggerOptions ¶
type LoggerOptions struct { // Name of the subsystem to prefix logs with Name string // The threshold for the logger. Anything less severe is supressed Level Level // Where to write the logs to. Defaults to os.Stderr if nil Output io.Writer // An optional Locker in case Output is shared. This can be a sync.Mutex or // a NoopLocker if the caller wants control over output, e.g. for batching // log lines. Mutex Locker // Control if the output should be in JSON. JSONFormat bool // Include file and line information in each log line IncludeLocation bool // The time format to use instead of the default TimeFormat string // Control whether or not to display the time at all. This is required // because setting TimeFormat to empty assumes the default format. DisableTime bool // Color the output. On Windows, colored logs are only avaiable for io.Writers that // are concretely instances of *os.File. Color ColorOption // A function which is called with the log information and if it returns true the value // should not be logged. // This is useful when interacting with a system that you wish to suppress the log // message for (because it's too noisy, etc) Exclude func(level Level, msg string, args ...interface{}) bool // IndependentLevels causes subloggers to be created with an independent // copy of this logger's level. This means that using SetLevel on this // logger will not effect any subloggers, and SetLevel on any subloggers // will not effect the parent or sibling loggers. IndependentLevels bool }
LoggerOptions can be used to configure a new logger.
type NoopLocker ¶
type NoopLocker struct{}
NoopLocker implements locker but does nothing. This is useful if the client wants tight control over locking, in order to provide grouping of log entries or other functionality.
type Octal ¶
type Octal int
A simple shortcut to format numbers in octal when displayed with the normal text output. For example: L.Info("perms", Octal(17))
type OutputResettable ¶
type OutputResettable interface { // ResetOutput swaps the current output writer with the one given in the // opts. Color options given in opts will be used for the new output. ResetOutput(opts *LoggerOptions) error // ResetOutputWithFlush swaps the current output writer with the one given // in the opts, first calling Flush on the given Flushable. Color options // given in opts will be used for the new output. ResetOutputWithFlush(opts *LoggerOptions, flushable Flushable) error }
OutputResettable provides ways to swap the output in use at runtime
type SinkAdapter ¶
SinkAdapter describes the interface that must be implemented in order to Register a new sink to an InterceptLogger
func NewSinkAdapter ¶
func NewSinkAdapter(opts *LoggerOptions) SinkAdapter
NewSinkAdapter returns a SinkAdapter with configured settings defined by LoggerOptions
type StandardLoggerOptions ¶
type StandardLoggerOptions struct { // Indicate that some minimal parsing should be done on strings to try // and detect their level and re-emit them. // This supports the strings like [ERROR], [ERR] [TRACE], [WARN], [INFO], // [DEBUG] and strip it off before reapplying it. InferLevels bool // ForceLevel is used to force all output from the standard logger to be at // the specified level. Similar to InferLevels, this will strip any level // prefix contained in the logged string before applying the forced level. // If set, this override InferLevels. ForceLevel Level }
StandardLoggerOptions can be used to configure a new standard logger.