klog is a permanant fork of https://github.com/golang/glog. original README from glog is below

• Replace imports for github.com/golang/glog with k8s.io/klog
• Use klog.InitFlags(nil) explicitly for initializing global flags as we no longer use init() method to register the flags
• You can now use log-file instead of log-dir for logging to a single file (See examples/log_file/usage_log_file.go)
• If you want to redirect everything logged using klog somewhere else (say syslog!), you can use klog.SetOutput() method and supply a io.Writer. (See examples/set_output/usage_set_output.go)
• If you want to keep the older glog in charge of actual logging but end up mixing files that use klog, you can use klog.SetOutput() for that as well. (See examples/coexist_glog/coexist_glog.go)
• Another pattern you can use is k8s.io/klog/glog which is a proxy that implements the older glog API with dep override (or fixing up just imports)

Leveled execution logs for Go.

This is an efficient pure Go implementation of leveled logs in the manner of the open source C++ package https://github.com/google/glog

By binding methods to booleans it is possible to use the log package without paying the expense of evaluating the arguments to the log. Through the -vmodule flag, the package also provides fine-grained control over logging at the file level.

The comment from glog.go introduces the ideas:

Package glog implements logging analogous to the Google-internal
C++ INFO/ERROR/V setup.  It provides functions Info, Warning,
Error, Fatal, plus formatting variants such as Infof. It
also provides V-style logging controlled by the -v and
-vmodule=file=2 flags.

Basic examples:

	glog.Info("Prepare to repel boarders")

	glog.Fatalf("Initialization failed: %s", err)

See the documentation for the V function for an explanation
of these examples:

	if glog.V(2) {
		glog.Info("Starting transaction...")
	}

	glog.V(2).Infoln("Processed", nItems, "elements")

The repository contains an open source version of the log package used inside Google. The master copy of the source lives inside Google, not here. The code in this repo is for export only and is not itself under development. Feature requests will be ignored.

Send bug reports to [email protected].