logger

Documentation

Overview

Package logger defines a type for writing to logs. It's just a convenience type so that we don't have to pass verbose func(...) types around.

Index

• func Discard(string, ...interface{})
• func FuncWriter(f Logf) io.Writer
• func StdLogger(f Logf) *log.Logger
• type ArgWriter
  • func (fn ArgWriter) Format(f fmt.State, _ rune)
• type Logf
  • func Filtered(logf Logf, allow func(s string) bool) Logf
  • func LogOnChange(logf Logf, maxInterval time.Duration, timeNow func() time.Time) Logf
  • func LogfCloser(logf Logf) (newLogf Logf, close func())
  • func RateLimitedFn(logf Logf, f time.Duration, burst int, maxCache int) Logf
  • func RusagePrefixLog(logf Logf) Logf
  • func WithPrefix(f Logf, prefix string) Logf

Functions

func Discard

func Discard(string, ...interface{})

Discard is a Logf that throws away the logs given to it.

func FuncWriter

func FuncWriter(f Logf) io.Writer

FuncWriter returns an io.Writer that writes to f.

func StdLogger

func StdLogger(f Logf) *log.Logger

StdLogger returns a standard library logger from a Logf.

Types

type ArgWriter

type ArgWriter func(*bufio.Writer)

ArgWriter is a fmt.Formatter that can be passed to any Logf func to efficiently write to a %v argument without allocations.

func (ArgWriter) Format

func (fn ArgWriter) Format(f fmt.State, _ rune)

type Logf

type Logf func(format string, args ...interface{})

Logf is the basic Tailscale logger type: a printf-like func. Like log.Printf, the format need not end in a newline. Logf functions must be safe for concurrent use.

func Filtered

func Filtered(logf Logf, allow func(s string) bool) Logf

Filtered returns a Logf that silently swallows some log lines. Each inbound format and args is evaluated and printed to a string s. The original format and args are passed to logf if and only if allow(s) returns true.

func LogOnChange

func LogOnChange(logf Logf, maxInterval time.Duration, timeNow func() time.Time) Logf

LogOnChange logs a given line only if line != lastLine, or if maxInterval has passed since the last time this identical line was logged.

func LogfCloser

func LogfCloser(logf Logf) (newLogf Logf, close func())

LogfCloser wraps logf to create a logger that can be closed. Calling close makes all future calls to newLogf into no-ops.

func RateLimitedFn

func RateLimitedFn(logf Logf, f time.Duration, burst int, maxCache int) Logf

RateLimitedFn returns a rate-limiting Logf wrapping the given logf. Messages are allowed through at a maximum of one message every f (where f is a time.Duration), in bursts of up to burst messages at a time. Up to maxCache strings will be held at a time.

func RusagePrefixLog

func RusagePrefixLog(logf Logf) Logf

RusagePrefixLog returns a Logf func wrapping the provided logf func that adds a prefixed log message to each line with the current binary memory usage and max RSS.

func WithPrefix

func WithPrefix(f Logf, prefix string) Logf

WithPrefix wraps f, prefixing each format with the provided prefix.