edwardbetts / xlog

:page_facing_up: Logging library for Go

xlog

Yet another logging package for Go.

The main thing about this package is that it's good for usage in libraries and doesn't involve itself with policy. Essentially, if, as a library, you want to log something, you write this:

var log, Log = xlog.NewQuiet("my.logger.name")

func Foo() {
  log.Debugf("Bar")
}

The log variable is what you use to log, and the Log variable is exported from the package and provides methods for controlling the log site. (These are actually two interfaces to the same object which enforce this pattern.)

The idea is that consuming code can call somepkg.Log to control where it logs to, at what verbosity, etc.

You should instantiate with NewQuiet if you are a library, as this suppresses most log messages by default. Loggers created with New don't suppress any log messages by default.

xlog uses a traditional Print/Printf interface. It also has the following conveniences:

• Methods ending in e, such as Debuge, take an error as their first argument and are no-ops if it is nil.

• Fatal and Panic call os.Exit(1) and Panic, respectively. The e variants of these are no-ops if the error is nil, providing a simple assertion mechanism.

xlog uses syslog severities (Emergency, Alert, Critical, Error, Warning, Notice, Info, Debug) and also provides a Trace severity which is even less severe than Debug. You should generally not emit Alert or Emergency severities from your code, as these are of system-level significance.

You can visit all registered log sites in order to configure loggers programmatically.

Loggers should be named via a dot-separated hierarchy with names in lowercase. If you have a repository called foo and a subpackage baz, naming the logger for that subpackage foo.baz might be reasonable.

Loggers are arranged in a hierarchy terminating in the root logger, which is configured to log to stderr by default. You can create a logger under another logger using NewUnder.

Licence

© 2014—2016 Hugo Landau <[email protected]>  MIT License

Licenced under the licence with SHA256 hash fd80a26fbb3f644af1fa994134446702932968519797227e07a1368dea80f0bc, a copy of which can be found here.