Documentation
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Overview ¶
Package logging provides a component-based logging framework for user and built-in Granitic components.
Logging in Granitic is covered in detail at http://granitic.io/1.0/ref/logging a brief description of the key concepts and types follows.
Component logging ¶
Every struct that is registered as a component in Granitic's IoC container has the option of having a Logger injected into it. Components are classified as framework components (built-in components that are created when you enable a facility in your application) and application components - named components defined in your application's component definition files.
Obtaining a Logger ¶
Any component in your application will have a Logger injected into it if the underlying struct for that component declares a field:
Log logging.Logger
The Logger is injected during the 'decoration' phase of container startup (see package documentation for the ioc pacakge). This means the Logger is safe to use in any method in your component.
Log levels ¶
A log level is a label indicating the relative significance of a message to be logged. In order of significance they are:
TRACE, DEBUG, INFO, WARN, ERROR, FATAL
These levels have no set meanings, but a rough set of meanings follows:
TRACE ¶
Very detailed low level messages showing almost line-by-line commentary of a procedure.
DEBUG ¶
Information that might be significant when trying to diagnose a fault (connection URLs, resource utilisation etc).
INFO ¶
Status information that might be of interest to outside observers of an application (ready messages, declaring which ports HTTP servers are listening to, shutdown notifications).
WARN ¶
An undesirable but managed situation where application or request integrity has not suffered (approaching a resource limit, having to retry a connection to an external system).
ERROR ¶
A problem that has not affected application integrity, but has caused a user request to terminate abnormally (problem inserting into a database, downstream system unavailable after retries).
FATAL ¶
A serious problem that has affected the integrity of the application such that it should be restarted or has crashed.
Log methods ¶
The Logger interface (see below) provides methods to log a message at a particular level. E.g.
Log.LogDebugf("A %s message", "DEBUG")
Global and component thresholds ¶
A log level threshold is the minimum significance of a message that will be actually written to a log file or console. Granitic maintains a separate global log level for application components and framework components. This separation means that you could, for example, set your application's global log level to DEBUG without having's Granitic's built-in components filling your log files with clutter.
The log levels can be adjusted in the configuration of your application by setting the following configuration in your application's configuration file:
{ "FrameworkLogger":{ "GlobalLogLevel": "INFO" }, "ApplicationLogger":{ "GlobalLogLevel": "INFO" } }
The above example is the default setting for Granitic applications, meaning that only messages with a log level of INFO or higher will actually be written to the console and/or log file.
The global log level can be overridden for individual components by setting configuration similar to:
{ "FrameworkLogger":{ "GlobalLogLevel": "FATAL", "ComponentLogLevels": { "grncHttpServer": "TRACE" } }, "ApplicationLogger":{ "GlobalLogLevel": "INFO", "ComponentLogLevels": { "noisyComponent": "ERROR" } } }
In this example, all framework components are effectively silenced (apart from fatal errors), but the HTTP server is allowed to output TRACE messages. Application components are allowed to log at INFO and above, but one component is too chatty so is only allowed to log at ERROR or above.
Log output ¶
Output of log messages to file and console is controlled by the LogWriting configuration element. The default settings look something like:
{ "LogWriting": { "EnableConsoleLogging": true, "EnableFileLogging": false, "File": { "LogPath": "./granitic.log", "BufferSize": 50 }, "Format": { "UtcTimes": true, "Unset": "-" } } }
For more information on these settings, refer to http://granitic.io/1.0/ref/logging#output
Runtime control ¶
Global log levels and component log levels can be changed at runtime, if your application has the RuntimeCtl facility enabled. See http://granitic.io/1.0/ref/runtime-ctl for more information
Log message prefixes ¶
Every message written to a log file or console can be given a customisable prefix containing meta-data like time of logging or information from a Context. See http://granitic.io/1.0/ref/logging#prefix
Index ¶
- Constants
- func LabelFromLevel(ll LogLevel) string
- type AsynchFileWriter
- type ByName
- type ComponentLevel
- type ComponentLevels
- type ComponentLoggerManager
- func (clm *ComponentLoggerManager) CreateLogger(componentId string) Logger
- func (clm *ComponentLoggerManager) CreateLoggerAtLevel(componentId string, threshold LogLevel) Logger
- func (clm *ComponentLoggerManager) CurrentLevels() []*ComponentLevel
- func (clm *ComponentLoggerManager) GlobalLevel() LogLevel
- func (clm *ComponentLoggerManager) LoggerByName(name string) *GraniticLogger
- func (clm *ComponentLoggerManager) PrepareToStop()
- func (clm *ComponentLoggerManager) ReadyToStop() (bool, error)
- func (clm *ComponentLoggerManager) SetGlobalThreshold(globalThreshold LogLevel)
- func (clm *ComponentLoggerManager) SetInitialLogLevels(ll map[string]interface{})
- func (clm *ComponentLoggerManager) Stop() error
- func (clm *ComponentLoggerManager) UpdateWritersAndFormatter(writers []LogWriter, formatter *LogMessageFormatter)
- type ConsoleErrorLogger
- func (l *ConsoleErrorLogger) IsLevelEnabled(level LogLevel) bool
- func (l *ConsoleErrorLogger) LogAtLevelf(level LogLevel, levelLabel string, format string, a ...interface{})
- func (l *ConsoleErrorLogger) LogAtLevelfCtx(ctx context.Context, level LogLevel, levelLabel string, format string, ...)
- func (l *ConsoleErrorLogger) LogDebugf(format string, a ...interface{})
- func (l *ConsoleErrorLogger) LogDebugfCtx(ctx context.Context, s string, a ...interface{})
- func (l *ConsoleErrorLogger) LogErrorf(format string, a ...interface{})
- func (l *ConsoleErrorLogger) LogErrorfCtx(ctx context.Context, format string, a ...interface{})
- func (l *ConsoleErrorLogger) LogErrorfCtxWithTrace(ctx context.Context, format string, a ...interface{})
- func (l *ConsoleErrorLogger) LogErrorfWithTrace(format string, a ...interface{})
- func (l *ConsoleErrorLogger) LogFatalf(format string, a ...interface{})
- func (l *ConsoleErrorLogger) LogFatalfCtx(ctx context.Context, format string, a ...interface{})
- func (l *ConsoleErrorLogger) LogInfof(format string, a ...interface{})
- func (l *ConsoleErrorLogger) LogInfofCtx(ctx context.Context, s string, a ...interface{})
- func (l *ConsoleErrorLogger) LogTracef(format string, a ...interface{})
- func (l *ConsoleErrorLogger) LogTracefCtx(ctx context.Context, s string, a ...interface{})
- func (l *ConsoleErrorLogger) LogWarnf(format string, a ...interface{})
- func (l *ConsoleErrorLogger) LogWarnfCtx(ctx context.Context, s string, a ...interface{})
- type ConsoleWriter
- type GlobalLevel
- type GraniticLogger
- func (grl *GraniticLogger) IsLevelEnabled(level LogLevel) bool
- func (grl *GraniticLogger) LogAtLevelf(level LogLevel, levelLabel string, format string, a ...interface{})
- func (grl *GraniticLogger) LogAtLevelfCtx(ctx context.Context, level LogLevel, levelLabel string, format string, ...)
- func (grl *GraniticLogger) LogDebugf(format string, a ...interface{})
- func (grl *GraniticLogger) LogDebugfCtx(ctx context.Context, format string, a ...interface{})
- func (grl *GraniticLogger) LogErrorf(format string, a ...interface{})
- func (grl *GraniticLogger) LogErrorfCtx(ctx context.Context, format string, a ...interface{})
- func (grl *GraniticLogger) LogErrorfCtxWithTrace(ctx context.Context, format string, a ...interface{})
- func (grl *GraniticLogger) LogErrorfWithTrace(format string, a ...interface{})
- func (grl *GraniticLogger) LogFatalf(format string, a ...interface{})
- func (grl *GraniticLogger) LogFatalfCtx(ctx context.Context, format string, a ...interface{})
- func (grl *GraniticLogger) LogInfof(format string, a ...interface{})
- func (grl *GraniticLogger) LogInfofCtx(ctx context.Context, format string, a ...interface{})
- func (grl *GraniticLogger) LogTracef(format string, a ...interface{})
- func (grl *GraniticLogger) LogTracefCtx(ctx context.Context, format string, a ...interface{})
- func (grl *GraniticLogger) LogWarnf(format string, a ...interface{})
- func (grl *GraniticLogger) LogWarnfCtx(ctx context.Context, format string, a ...interface{})
- func (grl *GraniticLogger) SetLocalThreshold(threshold LogLevel)
- func (grl *GraniticLogger) UpdateWritersAndFormatter(w []LogWriter, f *LogMessageFormatter)
- type LogLevel
- type LogMessageFormatter
- type LogWriter
- type Logger
- type RuntimeControllableLog
Constants ¶
const ( All = 0 Trace = 10 Debug = 20 Info = 40 Warn = 50 Error = 60 Fatal = 70 )
const ( AllLabel = "ALL" TraceLabel = "TRACE" DebugLabel = "DEBUG" InfoLabel = "INFO" WarnLabel = "WARN" ErrorLabel = "ERROR" FatalLabel = "FATAL" )
const FrameworkPresetPrefix = "framework"
const PresetFormatFramework = "%{02/Jan/2006:15:04:05 Z0700}t %P [%c] "
The default prefix format for log lines
Variables ¶
This section is empty.
Functions ¶
func LabelFromLevel ¶
LabelFromLevel takes a member of the LogLevel enumeration (All, Fatal) and converts it to a string code ('ALL', 'FATAL'). If the supplied LogLevel cannot be mapped to a defined level, the word 'CUSTOM' is returned.
Types ¶
type AsynchFileWriter ¶
type AsynchFileWriter struct { //The number of messages that can be queued for writing before calls to WriteMessage block. BufferSize int //The file (absolute path or relative to application's working directory) that log messages should be appended to. LogPath string // contains filtered or unexported fields }
Implementation of LogWriter that appends a message to a file. Messages will be written asynchronously as long as the number of messages queued for writing does not exceed the value of BufferSize
func (*AsynchFileWriter) Busy ¶
func (cw *AsynchFileWriter) Busy() bool
Returns true if one or more messages are queued for writing.
func (*AsynchFileWriter) Init ¶
func (afw *AsynchFileWriter) Init() error
Creates a channel to act as a buffer for queued messages
func (*AsynchFileWriter) WriteMessage ¶
func (afw *AsynchFileWriter) WriteMessage(m string)
WriteMessage queues a message for writing and returns immediately, as long as the number of queued messages does not exceed BufferSize.
type ByName ¶
type ByName struct{ ComponentLevels }
type ComponentLevel ¶
Pairs a component named and its loglevel for sorting and presentation through RuntimeCtl
type ComponentLevels ¶
type ComponentLevels []*ComponentLevel
func (ComponentLevels) Len ¶
func (s ComponentLevels) Len() int
func (ComponentLevels) Swap ¶
func (s ComponentLevels) Swap(i, j int)
type ComponentLoggerManager ¶
type ComponentLoggerManager struct {
// contains filtered or unexported fields
}
Creates new Logger instances for a particular scope (e.g. framework or application).
func CreateComponentLoggerManager ¶
func CreateComponentLoggerManager(globalThreshold LogLevel, initalComponentLogLevels map[string]interface{}, writers []LogWriter, formatter *LogMessageFormatter) *ComponentLoggerManager
CreateComponentLoggerManager creates a new ComponentLoggerManager with a global level and default values for named components.
func (*ComponentLoggerManager) CreateLogger ¶
func (clm *ComponentLoggerManager) CreateLogger(componentId string) Logger
Create a new Logger for the supplied component name
func (*ComponentLoggerManager) CreateLoggerAtLevel ¶
func (clm *ComponentLoggerManager) CreateLoggerAtLevel(componentId string, threshold LogLevel) Logger
Create a new Logger for the supplied component name with the local log threshold set to the supplied level.
func (*ComponentLoggerManager) CurrentLevels ¶
func (clm *ComponentLoggerManager) CurrentLevels() []*ComponentLevel
Returns the current local log level for all Loggers managed by this component.
func (*ComponentLoggerManager) GlobalLevel ¶
func (clm *ComponentLoggerManager) GlobalLevel() LogLevel
Returns the global log level for the scope (application, framework) that this ComponentLoggerManager is responsible for.
func (*ComponentLoggerManager) LoggerByName ¶
func (clm *ComponentLoggerManager) LoggerByName(name string) *GraniticLogger
Finds a previously created Logger by the name it was given when it was created. Returns nil if no Logger by that name exists.
func (*ComponentLoggerManager) PrepareToStop ¶
func (clm *ComponentLoggerManager) PrepareToStop()
Does nothing
func (*ComponentLoggerManager) ReadyToStop ¶
func (clm *ComponentLoggerManager) ReadyToStop() (bool, error)
Returns false if any of the LogWriters attached to this component are actively writing.
func (*ComponentLoggerManager) SetGlobalThreshold ¶
func (clm *ComponentLoggerManager) SetGlobalThreshold(globalThreshold LogLevel)
Sets the global log level for the scope (application, framework) that this ComponentLoggerManager is responsible for.
func (*ComponentLoggerManager) SetInitialLogLevels ¶
func (clm *ComponentLoggerManager) SetInitialLogLevels(ll map[string]interface{})
Provide a map of component names to log levels. If a Logger is subsequently created for a component named in the map, the log level in the map will be used to set its local log threshold.
func (*ComponentLoggerManager) Stop ¶
func (clm *ComponentLoggerManager) Stop() error
Closes all LogWriters attached to this component.
func (*ComponentLoggerManager) UpdateWritersAndFormatter ¶
func (clm *ComponentLoggerManager) UpdateWritersAndFormatter(writers []LogWriter, formatter *LogMessageFormatter)
Updates the writers and formatters of all Loggers managed by this ComponentLoggerManager.
type ConsoleErrorLogger ¶
type ConsoleErrorLogger struct { }
An implementation of logging.Logger that writes errors and fatal messages to the console/command line using Go's fmt.Printf function. Messages at all other levels are ignored. This implementation is used by Granitic's command line tools and is not recommended for use in user applications.
func (*ConsoleErrorLogger) IsLevelEnabled ¶
func (l *ConsoleErrorLogger) IsLevelEnabled(level LogLevel) bool
IsLevelEnabled returns true if the supplied level is >= Error
func (*ConsoleErrorLogger) LogAtLevelf ¶
func (l *ConsoleErrorLogger) LogAtLevelf(level LogLevel, levelLabel string, format string, a ...interface{})
LogAtLevelf uses fmt.printf to write the supplied message to the console.
func (*ConsoleErrorLogger) LogAtLevelfCtx ¶
func (l *ConsoleErrorLogger) LogAtLevelfCtx(ctx context.Context, level LogLevel, levelLabel string, format string, a ...interface{})
LogAtLevelfCtx uses fmt.printf to write the supplied message to the console.
func (*ConsoleErrorLogger) LogDebugf ¶
func (l *ConsoleErrorLogger) LogDebugf(format string, a ...interface{})
Ignored - messages sent to this method are discarded.
func (*ConsoleErrorLogger) LogDebugfCtx ¶
func (l *ConsoleErrorLogger) LogDebugfCtx(ctx context.Context, s string, a ...interface{})
Ignored - messages sent to this method are discarded.
func (*ConsoleErrorLogger) LogErrorf ¶
func (l *ConsoleErrorLogger) LogErrorf(format string, a ...interface{})
LogErrorf uses fmt.printf to write the supplied message to the console.
func (*ConsoleErrorLogger) LogErrorfCtx ¶
func (l *ConsoleErrorLogger) LogErrorfCtx(ctx context.Context, format string, a ...interface{})
LogErrorfCtx uses fmt.printf to write the supplied message to the console.
func (*ConsoleErrorLogger) LogErrorfCtxWithTrace ¶
func (l *ConsoleErrorLogger) LogErrorfCtxWithTrace(ctx context.Context, format string, a ...interface{})
LogErrorfCtxWithTrace uses fmt.printf to write the supplied message to the console and appends a stack trace.
func (*ConsoleErrorLogger) LogErrorfWithTrace ¶
func (l *ConsoleErrorLogger) LogErrorfWithTrace(format string, a ...interface{})
LogErrorf uses fmt.printf to write the supplied message to the console and appends a stack trace.
func (*ConsoleErrorLogger) LogFatalf ¶
func (l *ConsoleErrorLogger) LogFatalf(format string, a ...interface{})
LogFatalf uses fmt.printf to write the supplied message to the console.
func (*ConsoleErrorLogger) LogFatalfCtx ¶
func (l *ConsoleErrorLogger) LogFatalfCtx(ctx context.Context, format string, a ...interface{})
LogFatalfCtx uses fmt.printf to write the supplied message to the console.
func (*ConsoleErrorLogger) LogInfof ¶
func (l *ConsoleErrorLogger) LogInfof(format string, a ...interface{})
Ignored - messages sent to this method are discarded.
func (*ConsoleErrorLogger) LogInfofCtx ¶
func (l *ConsoleErrorLogger) LogInfofCtx(ctx context.Context, s string, a ...interface{})
Ignored - messages sent to this method are discarded.
func (*ConsoleErrorLogger) LogTracef ¶
func (l *ConsoleErrorLogger) LogTracef(format string, a ...interface{})
Ignored - messages sent to this method are discarded.
func (*ConsoleErrorLogger) LogTracefCtx ¶
func (l *ConsoleErrorLogger) LogTracefCtx(ctx context.Context, s string, a ...interface{})
Ignored - messages sent to this method are discarded.
func (*ConsoleErrorLogger) LogWarnf ¶
func (l *ConsoleErrorLogger) LogWarnf(format string, a ...interface{})
Ignored - messages sent to this method are discarded.
func (*ConsoleErrorLogger) LogWarnfCtx ¶
func (l *ConsoleErrorLogger) LogWarnfCtx(ctx context.Context, s string, a ...interface{})
Ignored - messages sent to this method are discarded.
type ConsoleWriter ¶
type ConsoleWriter struct { }
Implementation of LogWriter that sends messages to the console/stdout using the fmt.Print method
func (*ConsoleWriter) WriteMessage ¶
func (cw *ConsoleWriter) WriteMessage(m string)
Passes message to fmt.Print
type GlobalLevel ¶
type GlobalLevel interface { //GlobalLevel returns this component's current global log level GlobalLevel() LogLevel }
Implemented by Loggers able to state what the current global log level is
type GraniticLogger ¶
type GraniticLogger struct {
// contains filtered or unexported fields
}
Standard implementation of Logger which respects both a global log level and a specific level for this Logger.
func (*GraniticLogger) IsLevelEnabled ¶
func (grl *GraniticLogger) IsLevelEnabled(level LogLevel) bool
See Logger.IsLevelEnabled
func (*GraniticLogger) LogAtLevelf ¶
func (grl *GraniticLogger) LogAtLevelf(level LogLevel, levelLabel string, format string, a ...interface{})
See Logger.LogAtLevelf
func (*GraniticLogger) LogAtLevelfCtx ¶
func (grl *GraniticLogger) LogAtLevelfCtx(ctx context.Context, level LogLevel, levelLabel string, format string, a ...interface{})
See Logger.LogAtLevelfCtx
func (*GraniticLogger) LogDebugf ¶
func (grl *GraniticLogger) LogDebugf(format string, a ...interface{})
See Logger.LogDebugf
func (*GraniticLogger) LogDebugfCtx ¶
func (grl *GraniticLogger) LogDebugfCtx(ctx context.Context, format string, a ...interface{})
See Logger.LogDebugfCtx
func (*GraniticLogger) LogErrorf ¶
func (grl *GraniticLogger) LogErrorf(format string, a ...interface{})
See Logger.LogErrorf
func (*GraniticLogger) LogErrorfCtx ¶
func (grl *GraniticLogger) LogErrorfCtx(ctx context.Context, format string, a ...interface{})
See Logger.LogErrorfCtx
func (*GraniticLogger) LogErrorfCtxWithTrace ¶
func (grl *GraniticLogger) LogErrorfCtxWithTrace(ctx context.Context, format string, a ...interface{})
See Logger.LogErrorfCtxWithTrace
func (*GraniticLogger) LogErrorfWithTrace ¶
func (grl *GraniticLogger) LogErrorfWithTrace(format string, a ...interface{})
See Logger.LogErrorfWithTrace
func (*GraniticLogger) LogFatalf ¶
func (grl *GraniticLogger) LogFatalf(format string, a ...interface{})
See Logger.LogFatalf
func (*GraniticLogger) LogFatalfCtx ¶
func (grl *GraniticLogger) LogFatalfCtx(ctx context.Context, format string, a ...interface{})
See Logger.LogFatalfCtx
func (*GraniticLogger) LogInfof ¶
func (grl *GraniticLogger) LogInfof(format string, a ...interface{})
See Logger.LogInfof
func (*GraniticLogger) LogInfofCtx ¶
func (grl *GraniticLogger) LogInfofCtx(ctx context.Context, format string, a ...interface{})
See Logger.LogInfofCtx
func (*GraniticLogger) LogTracef ¶
func (grl *GraniticLogger) LogTracef(format string, a ...interface{})
See Logger.LogTracef
func (*GraniticLogger) LogTracefCtx ¶
func (grl *GraniticLogger) LogTracefCtx(ctx context.Context, format string, a ...interface{})
See Logger.LogTracefCtx
func (*GraniticLogger) LogWarnf ¶
func (grl *GraniticLogger) LogWarnf(format string, a ...interface{})
See Logger.LogWarnf
func (*GraniticLogger) LogWarnfCtx ¶
func (grl *GraniticLogger) LogWarnfCtx(ctx context.Context, format string, a ...interface{})
See Logger.LogWarnfCtx
func (*GraniticLogger) SetLocalThreshold ¶
func (grl *GraniticLogger) SetLocalThreshold(threshold LogLevel)
Sets the log threshold for this Logger
func (*GraniticLogger) UpdateWritersAndFormatter ¶
func (grl *GraniticLogger) UpdateWritersAndFormatter(w []LogWriter, f *LogMessageFormatter)
See RuntimeControllableLog.UpdateWritersAndFormatter
type LogLevel ¶
type LogLevel uint
Numeric score of the significance of a message, where zero is non-significant and higher values are more significant.
func LogLevelFromLabel ¶
LogLevelFromLabel takes a string name for a log level (TRACE, DEBUG etc) and finds a numeric threshold associated with that type of message.
type LogMessageFormatter ¶
type LogMessageFormatter struct { // The pattern to be used as a template when generating prefixes. Mutally exclusive with PrefixPreset PrefixFormat string // The name of a pre-defined prefix template (e.g. 'framework'). Mutally exclusive with PrefixFormat PrefixPreset string // Convert timestamps in prefixes to UTC UtcTimes bool // The symbol to use in place of an unset variable in a log line prefix. Unset string // contains filtered or unexported fields }
A component able to take a message to be written to a log file and prefix it with a formatted template which can include log times, data from a Context etc.
func NewFrameworkLogMessageFormatter ¶
func NewFrameworkLogMessageFormatter() *LogMessageFormatter
NewFrameworkLogMessageFormatter creates a new LogMessageFormatter using the default 'framework' pattern for log line prefixes and UTC timestamps.
func (*LogMessageFormatter) Format ¶
func (lmf *LogMessageFormatter) Format(ctx context.Context, levelLabel, loggerName, message string) string
Format takes the message and prefixes it according the the rule specified in PrefixFormat or PrefixPreset
func (*LogMessageFormatter) Init ¶
func (lmf *LogMessageFormatter) Init() error
Checks that a valid format has been provided for the log message prefixes.
type LogWriter ¶
type LogWriter interface { // WriteMessage request that the supplied message be written. Depending on implementation, may be asynchronous. WriteMessage(string) // Close any resources (file handles etc) that this LogWriter might be holding. Close() // Returns true if the LogWriter is currently in the process of writing a log line. Busy() bool }
Implemented by components able to write a log message (to a file, console etc)
type Logger ¶
type Logger interface { //LogTracefCtx log a message at TRACE level with a Context LogTracefCtx(ctx context.Context, format string, a ...interface{}) //LogDebugfCtx log a message at DEBUG level with a Context LogDebugfCtx(ctx context.Context, format string, a ...interface{}) //LogInfofCtx log a message at INFO level with a Context LogInfofCtx(ctx context.Context, format string, a ...interface{}) //LogWarnfCtx log a message at WARN level with a Context LogWarnfCtx(ctx context.Context, format string, a ...interface{}) //LogErrorfCtx log a message at ERROR level with a Context LogErrorfCtx(ctx context.Context, format string, a ...interface{}) //LogErrorfCtxWithTrace log a message at ERROR level with a Context. Message output will be followed by a partial stack trace. LogErrorfCtxWithTrace(ctx context.Context, format string, a ...interface{}) //LogFatalfCtx log a message at FATAL level with a Context LogFatalfCtx(ctx context.Context, format string, a ...interface{}) //LogAtLevelfCtx log at the specified level with a Context LogAtLevelfCtx(ctx context.Context, level LogLevel, levelLabel string, format string, a ...interface{}) //LogTracef log a message at TRACE level LogTracef(format string, a ...interface{}) //LogDebugf log a message at DEBUG level LogDebugf(format string, a ...interface{}) //LogInfof log a message at INFO level LogInfof(format string, a ...interface{}) //LogWarnf log a message at WARN level LogWarnf(format string, a ...interface{}) //LogErrorf log a message at ERROR level LogErrorf(format string, a ...interface{}) //LogErrorfWithTrace log a message at ERROR level. Message output will be followed by a partial stack trace. LogErrorfWithTrace(format string, a ...interface{}) //LogFatalf log a message at FATAL level LogFatalf(format string, a ...interface{}) //LogAtLevelfCtx log at the specified level LogAtLevelf(level LogLevel, levelLabel string, format string, a ...interface{}) //IsLevelEnabled returns true if a message at the supplied level would acutally be logged. Useful to check //if the construction of a message would be expensive or slow. IsLevelEnabled(level LogLevel) bool }
The interface used by application code to submit a message to potentially be logged to a file or console. Methods are of the form
Log[Level]f Log[Level]fCtx
The Ctx versions of methods accept a Context. The Context is made available to the LogWriter implementations that write to files so that information in the Context can be potentially included in log line prefixes.
The f suffix indicates that the methods accept the same templates and variadic arguments as fmt.Printf
func CreateAnonymousLogger ¶
CreateAnonymousLogger creates a new Logger without attaching it to a LogManager. Useful for tests.
type RuntimeControllableLog ¶
type RuntimeControllableLog interface { //SetThreshold sets the logger's log level to the specified level SetThreshold(threshold LogLevel) //UpdateWritersAndFormatter causes the Logger to discard its current LogWriters and LogMessageFormatter in favour of the ones supplied. UpdateWritersAndFormatter([]LogWriter, *LogMessageFormatter) }
Implemented by loggers that can be modified at runtime