log

Documentation

Index

• Constants
• func CtxWith(ctx context.Context, logger Logger) context.Context
• func Debug(msg string, ctx ...interface{})
• func Discard()
• func Error(msg string, ctx ...interface{})
• func Flush()
• func HandlePanic()
• func Info(msg string, ctx ...interface{})
• func SafeDebug(l Logger, msg string, fields ...interface{})
• func SafeError(l Logger, msg string, fields ...interface{})
• func SafeInfo(l Logger, msg string, fields ...interface{})
• func Setup(cfg Config) error
• type Config
  • func (c *Config) ConfigName() string
  • func (c *Config) InitDefaults()
  • func (c *Config) Sample(dst io.Writer, path config.Path, ctx config.CtxMap)
• type ConsoleConfig
  • func (c *ConsoleConfig) InitDefaults()
• type DebugID
  • func NewDebugID() DebugID
  • func (id DebugID) String() string
• type DiscardLogger
  • func (DiscardLogger) Debug(msg string, ctx ...interface{})
  • func (DiscardLogger) Error(msg string, ctx ...interface{})
  • func (DiscardLogger) Info(msg string, ctx ...interface{})
  • func (d DiscardLogger) New(ctx ...interface{}) Logger
• type Level
  • func (l Level) ServeHTTP(w http.ResponseWriter, r *http.Request)
• type Logger
  • func FromCtx(ctx context.Context) Logger
  • func New(ctx ...interface{}) Logger
  • func Root() Logger
  • func SafeNewLogger(l Logger, fields ...interface{}) Logger
• type Span
  • func (s Span) Debug(msg string, ctx ...interface{})
  • func (s Span) Error(msg string, ctx ...interface{})
  • func (s Span) Info(msg string, ctx ...interface{})
  • func (s Span) New(ctx ...interface{}) Logger

Examples

• DiscardLogger

Constants

const (
	// DefaultConsoleLevel is the default log level for the console.
	DefaultConsoleLevel = "info"
	// DefaultStacktraceLevel is the default log level for which stack traces are included.
	DefaultStacktraceLevel = "error"
)

Functions

func CtxWith

func CtxWith(ctx context.Context, logger Logger) context.Context

CtxWith returns a new context, based on ctx, that embeds argument logger. The logger can be recovered using GetLogger. Attaching a logger to a context which already contains one will overwrite the existing value.

func Debug

func Debug(msg string, ctx ...interface{})

Debug logs at debug level.

func Discard

func Discard()

Discard sets the logger up to discard all log entries. This is useful for testing.

func Error

func Error(msg string, ctx ...interface{})

Error logs at error level.

func Flush

func Flush()

Flush writes the logs to the underlying buffer.

func HandlePanic

func HandlePanic()

HandlePanic catches panics and logs them.

func Info

func Info(msg string, ctx ...interface{})

Info logs at info level.

func SafeDebug

func SafeDebug(l Logger, msg string, fields ...interface{})

SafeDebug logs to l only if l is not nil.

func SafeError

func SafeError(l Logger, msg string, fields ...interface{})

SafeError logs to l only if l is not nil.

func SafeInfo

func SafeInfo(l Logger, msg string, fields ...interface{})

SafeInfo logs to l only if l is not nil.

func Setup

func Setup(cfg Config) error

Setup configures the logging library with the given config.

Types

type Config

type Config struct {
	config.NoValidator
	// Console is the configuration for the console logging.
	Console ConsoleConfig `toml:"console,omitempty"`
}

Config is the configuration for the logger.

func (*Config) ConfigName

func (c *Config) ConfigName() string

ConfigName returns the name this config should have in a struct embedding this.

func (*Config) InitDefaults

func (c *Config) InitDefaults()

InitDefaults populates unset fields in cfg to their default values (if they have one).

func (*Config) Sample

func (c *Config) Sample(dst io.Writer, path config.Path, ctx config.CtxMap)

Sample writes the sample configuration to the dst writer.

type ConsoleConfig

type ConsoleConfig struct {
	// Level of console logging (defaults to DefaultConsoleLevel).
	Level string `toml:"level,omitempty"`
	// Format of the console logging. (human|json)
	Format string `toml:"format,omitempty"`
	// StacktraceLevel sets from which level stacktraces are included.
	StacktraceLevel string `toml:"stacktrace_level,omitempty"`
}

ConsoleConfig is the config for the console logger.

func (*ConsoleConfig) InitDefaults

func (c *ConsoleConfig) InitDefaults()

InitDefaults populates unset fields in cfg to their default values (if they have one).

type DebugID

type DebugID uint32

DebugID is used to correlate behavior in logs. A DebugID is allocated for each outgoing request/response or notify message exchange, and for each handler executed during ListenAndServe.

func NewDebugID

func NewDebugID() DebugID

NewDebugID creates a new debug id.

func (DebugID) String

func (id DebugID) String() string

type DiscardLogger

type DiscardLogger struct{}

DiscardLogger implements the Logger interface and discards all messages. Subloggers created from this logger will also discard all messages and ignore the additional context.

To see how to use this, see the example.

Example

// LITERALINCLUDE ExampleDiscardLogger START
type Server struct {
	// Logger is used by the server to log information about internal events. If nil, logging
	// is disabled.
	Logger Logger
}

// Use a func because this is a godoc example, but this would normally be something like
// s.Run().
Run := func(s *Server) {
	if s.Logger == nil {
		s.Logger = DiscardLogger{}
	}
	s.Logger.Debug("this message is discarded now")
}

Run(&Server{})
// LITERALINCLUDE ExampleDiscardLogger END

func (DiscardLogger) Debug

func (DiscardLogger) Debug(msg string, ctx ...interface{})

func (DiscardLogger) Error

func (DiscardLogger) Error(msg string, ctx ...interface{})

func (DiscardLogger) Info

func (DiscardLogger) Info(msg string, ctx ...interface{})

func (DiscardLogger) New

func (d DiscardLogger) New(ctx ...interface{}) Logger

type Level

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

Level allows to interact with the logging level at runtime.

var ConsoleLevel Level

ConsoleLevel allows interacting with the logging level at runtime. It is initialized with after a successful call to Setup.

func (Level) ServeHTTP

func (l Level) ServeHTTP(w http.ResponseWriter, r *http.Request)

ServeHTTP is an endpoint that can report on or change the current logging level.

GET requests return a JSON description of the current logging level. PUT requests change the logging level and expect a payload like:

{"level":"info"}

type Logger

type Logger interface {
	New(ctx ...interface{}) Logger
	Debug(msg string, ctx ...interface{})
	Info(msg string, ctx ...interface{})
	Error(msg string, ctx ...interface{})
}

Logger describes the logger interface.

func FromCtx

func FromCtx(ctx context.Context) Logger

FromCtx returns the logger embedded in ctx if one exists, or the root logger otherwise. FromCtx is guaranteed to never return nil.

func New

func New(ctx ...interface{}) Logger

New creates a logger with the given context.

func Root

func Root() Logger

Root returns the root logger. It's a logger without any context.

func SafeNewLogger

func SafeNewLogger(l Logger, fields ...interface{}) Logger

SafeNewLogger creates a new logger as a child of l only if l is not nil. If l is nil, then nil is returned.

type Span

type Span struct {
	Logger Logger
	Span   opentracing.Span
}

Span is a logger that attaches all logs to the span.

func (Span) Debug

func (s Span) Debug(msg string, ctx ...interface{})

Debug logs to the logger and span.

func (Span) Error

func (s Span) Error(msg string, ctx ...interface{})

Error logs to the logger and span.

func (Span) Info

func (s Span) Info(msg string, ctx ...interface{})

Info logs to the logger and span.

func (Span) New

func (s Span) New(ctx ...interface{}) Logger

New creates a new logger with the context attached.