log

README

log - uniformly configurable loggers

go get -u "tawesoft.co.uk/go"

import "tawesoft.co.uk/go/log"

Links	License	Stable?
home ∙ docs ∙ src	MIT-0	candidate

About

Package log provides a common way to quickly configure a logging implementation with file rotation, syslog, console output, etc. for some popular logging implementations such as zerolog.

This package defines the configuration interface, which is json-encodable.

Loggers are concretely implemented by the packages in the subfolder e.g. tawesoft.co.uk/go/log/zerolog.

The package also wraps the stdlib syslog as an interface without it being a compile-time constraint so that it can be imported on platforms that don't support syslog (like Windows), giving a runtime error if used instead.

Getting Help

This package is part of tawesoft.co.uk/go, a monorepo for small Go modules maintained by Tawesoft®. Check out that URL for more information about other Go modules from Tawesoft plus community and commercial support options.

Documentation

Overview

Package log provides a common way to quickly configure a logging implementation with file rotation, syslog, console output, etc. for some popular logging implementations such as zerolog.

This package defines the configuration interface, which is json-encodable.

Loggers are concretely implemented by the packages in the subfolder e.g. tawesoft.co.uk/go/log/zerolog.

The package also wraps the stdlib syslog as an interface without it being a compile-time constraint so that it can be imported on platforms that don't support syslog (like Windows), giving a runtime error if used instead.

Package Information

License: MIT-0 (see LICENSE.txt)

Stable: candidate

For more information, documentation, source code, examples, support, links, etc. please see https://www.tawesoft.co.uk/go and https://www.tawesoft.co.uk/go/log

Index

• type Config
• type ConfigFile
  • func (c ConfigFile) MarshalJSON() ([]byte, error)
  • func (c *ConfigFile) UnmarshalJSON(data []byte) error
• type ConfigStderr
  • func (c ConfigStderr) ShouldColorize(output *os.File) bool
• type ConfigSyslog
  • func (c ConfigSyslog) Dial() (Syslog, error)
  • func (c ConfigSyslog) MarshalJSON() ([]byte, error)
  • func (c *ConfigSyslog) UnmarshalJSON(data []byte) error
• type Priority
  • func ParsePriority(str string) (Priority, error)
  • func (p Priority) String() string
• type Syslog

Types

type Config

type Config struct {
	Syslog ConfigSyslog
	File   ConfigFile
	Stderr ConfigStderr
}

type ConfigFile

type ConfigFile struct {
	Enabled bool

	// Mode to use when creating the file e.g. 0644, 0600
	Mode os.FileMode

	// Path to write the current (non-rotated) file. Rotated files appear
	// in the same directory.
	Path string

	// If Rotate is true, logs are rotated (e.g. like logrotate) once they
	// get to a certain size.
	Rotate bool

	// If RotateCompress is true, rotated log files are compressed (read them
	// with zless, zcat, or gunzip, for example)
	RotateCompress bool

	// A log is rotated if it would be bigger than RotateMaxSize (in bytes)
	RotateMaxSize int // bytes

	// If non-zero, delete any rotated logs older than RotateKeepAge
	RotateKeepAge time.Duration

	// If non-zero, keep only this many rotated logs and delete any exceeding
	// the limit of RotateKeepNumber.
	RotateKeepNumber int
}

ConfigFile configures a file logger, with optional file rotation

func (ConfigFile) MarshalJSON

func (c ConfigFile) MarshalJSON() ([]byte, error)

func (*ConfigFile) UnmarshalJSON

func (c *ConfigFile) UnmarshalJSON(data []byte) error

type ConfigStderr

type ConfigStderr struct {
	Enabled bool

	// If Color is true, output is colourised iff Stderr is attached to
	// a terminal.
	Color bool
}

ConfigStdio configures a logger which writes to Stderr

func (ConfigStderr) ShouldColorize

func (c ConfigStderr) ShouldColorize(output *os.File) bool

ShouldColorize returns true if the output should be colourised (if possible) for a given output (e.g. os.Stderr). This is true when both the config Color field is true and the output is a terminal.

type ConfigSyslog

type ConfigSyslog struct {
	Enabled  bool
	Network  string   // See syslog.Dial
	Address  string   // See syslog.Dial
	Priority Priority // See syslog.Dial
	Tag      string   // See syslog.Dial
}

ConfigSyslog configures a syslog logger

func (ConfigSyslog) Dial

func (c ConfigSyslog) Dial() (Syslog, error)

Dial connects to a local or remote syslog.

func (ConfigSyslog) MarshalJSON

func (c ConfigSyslog) MarshalJSON() ([]byte, error)

func (*ConfigSyslog) UnmarshalJSON

func (c *ConfigSyslog) UnmarshalJSON(data []byte) error

type Priority

type Priority int

Priority is a combination of the syslog facility and severity. See https://pkg.go.dev/log/syslog#Priority

const (
	LOG_EMERG Priority = iota
	LOG_ALERT
	LOG_CRIT
	LOG_ERR
	LOG_WARNING
	LOG_NOTICE
	LOG_INFO
	LOG_DEBUG
)

const (
	LOG_KERN Priority = iota << 3
	LOG_USER
	LOG_MAIL
	LOG_DAEMON
	LOG_AUTH
	LOG_SYSLOG // should only ever be used internally by syslogd
	LOG_LPR
	LOG_NEWS
	LOG_UUCP
	LOG_CRON
	LOG_AUTHPRIV
	LOG_FTP

	LOG_LOCAL0
	LOG_LOCAL1
	LOG_LOCAL2
	LOG_LOCAL3
	LOG_LOCAL4
	LOG_LOCAL5
	LOG_LOCAL6
	LOG_LOCAL7
)

func ParsePriority

func ParsePriority(str string) (Priority, error)

func (Priority) String

func (p Priority) String() string

type Syslog

type Syslog interface {
	io.Writer
	Close() error
	Debug(m string) error
	Info(m string) error
	Warning(m string) error
	Err(m string) error
	Emerg(m string) error
	Crit(m string) error
}

Syslog is syslog.Writer as an interface