Documentation
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Overview ¶
Package log provides a structured, levelled logger interface for use in server handlers, which handles multiple output streams. A typical use might be to log everything to stderr, but to add another logger to send important data off to The Default logger simply logs to stderr, a local File logger is available, and data can be extracted and sent elsewhere by additional loggers (for example page hits to a stats service).
Usage: logger,err := log.NewStdErr() log.Add(logger) log.Error(log.V{"key":value,"key":value})
Index ¶
- Constants
- Variables
- func Add(l StructuredLogger)
- func Debug(values map[string]interface{})
- func Error(values map[string]interface{})
- func Fatal(values map[string]interface{})
- func Info(values map[string]interface{})
- func Log(values map[string]interface{})
- func Middleware(h http.HandlerFunc) http.HandlerFunc
- func SetRequestID(r *http.Request, rid *RequestID) *http.Request
- func Time(start time.Time, values map[string]interface{})
- func Trace(r *http.Request) string
- type Default
- type File
- type Logger
- type RequestID
- type StructuredLogger
- type V
- type Values
Constants ¶
const ( // Separator is used to separate key:value pairs Separator = ":" // PrefixDate constant for date prefixes PrefixDate = "2006-01-02 " // PrefixTime constants for time prefix PrefixTime = "15:04:05 " // PrefixDateTime constants for date + time prefix PrefixDateTime = "2006-01-02:15:04:05 " )
const ( // FileFlags serts the flags for OpenFile on the log file FileFlags = os.O_WRONLY | os.O_APPEND | os.O_CREATE // FilePermissions serts the perms for OpenFile on the log file FilePermissions = 0640 )
const ( // LevelKey is the key for setting level LevelKey = "level" // MessageKey is the key for a message MessageKey = "msg" // DurationKey is used by the Time function DurationKey = "duration" // ErrorKey is used for errors ErrorKey = "error" // IPKey is used for IP addresses (for colouring) IPKey = "ip" // URLKey is used for identifying URLs (for filtering) URLKey = "url" // TraceKey is used for trace ids emitted in middleware TraceKey = "trace" )
const ( LevelNone = iota LevelDebug LevelInfo LevelError LevelFatal )
Valid levels for logging.
Variables ¶
var ( // LevelNames is a list of human-readable for levels. LevelNames = []string{"none", "debug", "info", "error", "fatal"} // NoColor determines if a terminal is colourable or not NoColor = os.Getenv("TERM") == "dumb" // LevelColors is a list of human-friendly terminal colors for levels. LevelColors = []string{"\033[0m", "\033[34m", "\033[32m", "\033[33m", "\033[31m"} // TraceColor sets a for IP addresses or request id TraceColor = "\033[33m" // ClearColors clears all formatting ClearColors = "\033[0m" )
Functions ¶
func Add ¶ added in v1.5.2
func Add(l StructuredLogger)
Add adds the given logger to the list of outputs, it should not be called from other goroutines.
func Debug ¶ added in v1.5.2
func Debug(values map[string]interface{})
Debug sends the key/value map at level Debug to all registered (log)gers.
func Error ¶ added in v1.5.2
func Error(values map[string]interface{})
Error sends the key/value map at level Error to all registered loggers.
func Fatal ¶ added in v1.5.2
func Fatal(values map[string]interface{})
Fatal sends the key/value map at level Fatal to all registered loggers, no other action is taken.
func Info ¶ added in v1.5.2
func Info(values map[string]interface{})
Info sends the key/value map at level Info to all registered loggers.
func Log ¶ added in v1.5.2
func Log(values map[string]interface{})
Log sends the key/value map to all registered loggers. If level is not set, it defaults to LevelInfo.
func Middleware ¶ added in v1.5.2
func Middleware(h http.HandlerFunc) http.HandlerFunc
Middleware adds a logging wrapper and request tracing to requests.
func SetRequestID ¶ added in v1.5.2
SetRequestID saves the request id in the request context.
Types ¶
type Default ¶ added in v1.5.2
type Default struct {
// Prefix is used to prefix any log lines emitted.
Prefix string
// Level is the level above which input is ignored.
Level int
// Writer is the output of this logger.
Writer io.Writer
// Color sets whether terminal colour instructions are emitted.
Color bool
}
Default defines a default logger which simply logs to Writer, Writer is set to stderr, Level is LevelDebug and Prefix is empty by default.
func NewStdErr ¶ added in v1.5.2
NewStdErr returns a new StructuredLogger of type Default which writes to stderr. By default prefix is empty, and level is LevelDebug (the lowest), so all output is captured.
func (*Default) LevelColor ¶ added in v1.5.2
LevelColor returns the human-readable colour for this level.
func (*Default) LevelName ¶ added in v1.5.2
LevelName returns the human-readable name for this level.
func (*Default) LevelValue ¶ added in v1.5.2
LevelValue extracts the Level from values (if present) or returns 0 if not.
func (*Default) Log ¶ added in v1.5.2
Log logs the key:value pairs given to the writer. Keys are sorted before output in alphabetical order to ensure consistent results.
func (*Default) SortedKeys ¶ added in v1.5.2
SortedKeys returns an array of keys for a map sorted in alpha order, this means we get a predictable order for the map entries when we print. The special keys level and message are ommitted.
func (*Default) WriteString ¶ added in v1.5.2
WriteString writes the string to the Writer.
type Logger ¶
type Logger struct {
Filter string
// contains filtered or unexported fields
}
Logger conforms with the server.Logger interface
type RequestID ¶ added in v1.5.2
type RequestID struct {
// contains filtered or unexported fields
}
RequestID is but a simple token for tracing requests.
func GetRequestID ¶ added in v1.5.2
GetRequestID retreives the request id from a request.
type StructuredLogger ¶ added in v1.5.2
type StructuredLogger interface {
Log(V)
}
StructuredLogger defines an interface for loggers which may be added with Add() to the list of outputs.
Source Files