humanlog

README

humanlog

Read logs from stdin and prints them back to stdout, but prettier.

Using it

Grab a release or :

With Go installed

$ go get -u github.com/humanlogio/humanlog/...

On linux

wget -qO- https://github.com/humanlogio/humanlog/releases/download/0.6.1/humanlog_0.6.1_linux_amd64.tar.gz | tar xvz

On OS X

brew tap humanlogio/homebrew-tap
brew install humanlog

Example

If you emit logs in JSON or in logfmt, you will enjoy pretty logs when those entries are encountered by humanlog. Unrecognized lines are left unchanged.

$ humanlog < /var/log/logfile.log

Contributing

How to help:

• support more log formats: by submitting human.Handler implementations.
• live querying: add support for filtering in log output in real time.
• charting: some key-values have semantics that could be charted in real time. For instance, durations, frequency of numeric values, etc. See the l2met project.

Usage

NAME:
   humanlog - reads structured logs from stdin, makes them pretty on stdout!

USAGE:
   humanlog [global options] command [command options] [arguments...]

VERSION:
   0.6.1

AUTHOR:
   Antoine Grondin <antoinegrondin@gmail.com>

COMMANDS:
   help, h  Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --config value                    specify a config file to use, otherwise uses the default one
   --skip value                      keys to skip when parsing a log entry
   --keep value                      keys to keep when parsing a log entry
   --sort-longest                    sort by longest key after having sorted lexicographically
   --skip-unchanged                  skip keys that have the same value than the previous entry
   --truncate                        truncates values that are longer than --truncate-length
   --truncate-length value           truncate values that are longer than this length (default: 15)
   --color value                     specify color mode: auto, on/force, off (default: "auto")
   --light-bg                        use black as the base foreground color (for terminals with light backgrounds)
   --time-format value               output time format, see https://golang.org/pkg/time/ for details (default: "Jan _2 15:04:05")
   --ignore-interrupts, -i           ignore interrupts
   --message-fields value, -m value  Custom JSON fields to search for the log message. (i.e. mssge, data.body.message) [$HUMANLOG_MESSAGE_FIELDS]
   --time-fields value, -t value     Custom JSON fields to search for the log time. (i.e. logtime, data.body.datetime) [$HUMANLOG_TIME_FIELDS]
   --level-fields value, -l value    Custom JSON fields to search for the log level. (i.e. somelevel, data.level) [$HUMANLOG_LEVEL_FIELDS]
   --help, -h                        show help
   --version, -v                     print the version

Documentation

Index

• Variables
• func Scanner(src io.Reader, sink sink.Sink, opts *HandlerOptions) error
• type Handler
• type HandlerOptions
  • func HandlerOptionsFrom(cfg config.Config) *HandlerOptions
• type JSONHandler
  • func (h *JSONHandler) TryHandle(d []byte, out *model.Structured) bool
  • func (h *JSONHandler) UnmarshalJSON(data []byte) bool
• type LogfmtHandler
  • func (h *LogfmtHandler) TryHandle(d []byte, out *model.Structured) bool
  • func (h *LogfmtHandler) UnmarshalLogfmt(data []byte) bool

Variables

var DefaultOptions = &HandlerOptions{
	TimeFields:    []string{"time", "ts", "@timestamp", "timestamp"},
	MessageFields: []string{"message", "msg"},
	LevelFields:   []string{"level", "lvl", "loglevel", "severity"},
}

Functions

func Scanner

func Scanner(src io.Reader, sink sink.Sink, opts *HandlerOptions) error

Scanner reads JSON-structured lines from src and prettify them onto dst. If the lines aren't JSON-structured, it will simply write them out with no prettification.

Types

type Handler

type Handler interface {
	CanHandle(line []byte) bool
	Prettify(skipUnchanged bool) []byte
	logfmt.Handler
}

Handler can recognize it's log lines, parse them and prettify them.

type HandlerOptions

type HandlerOptions struct {
	TimeFields    []string
	MessageFields []string
	LevelFields   []string
}

func HandlerOptionsFrom

func HandlerOptionsFrom(cfg config.Config) *HandlerOptions

type JSONHandler

type JSONHandler struct {
	Opts *HandlerOptions

	Level   string
	Time    time.Time
	Message string
	Fields  map[string]string
}

JSONHandler can handle logs emitted by logrus.TextFormatter loggers.

func (*JSONHandler) TryHandle

func (h *JSONHandler) TryHandle(d []byte, out *model.Structured) bool

TryHandle tells if this line was handled by this handler.

func (*JSONHandler) UnmarshalJSON

func (h *JSONHandler) UnmarshalJSON(data []byte) bool

UnmarshalJSON sets the fields of the handler.

type LogfmtHandler

type LogfmtHandler struct {
	Opts *HandlerOptions

	Level   string
	Time    time.Time
	Message string
	Fields  map[string]string
}

LogfmtHandler can handle logs emmited by logrus.TextFormatter loggers.

func (*LogfmtHandler) TryHandle

func (h *LogfmtHandler) TryHandle(d []byte, out *model.Structured) bool

CanHandle tells if this line can be handled by this handler.

func (*LogfmtHandler) UnmarshalLogfmt

func (h *LogfmtHandler) UnmarshalLogfmt(data []byte) bool

HandleLogfmt sets the fields of the handler.