simonpasquier / klog-gokit

Replacement for klog for projects using the go-kit logger

klog-gokit

This package is a replacement for k8s.io/klog/v2 in projects that use the github.com/go-kit/log module for logging.

The current branch supports neither k8s.io/klog nor github.com/go-kit/kit. Please use the v2.1.0 version instead.

It is heavily inspired by the github.com/kubermatic/glog-gokit package.

Usage

Add this line to your go.mod file:

replace k8s.io/klog/v2 => github.com/simonpasquier/klog-gokit/v3 v3

In your main.go:

// Import the package like it is original klog
import (
    ...
    "github.com/go-kit/log"
    klog "k8s.io/klog/v2"
    ...
)

// Create go-kit logger in your main.go
logger := log.NewLogfmtLogger(log.NewSyncWriter(os.Stdout))
logger = log.With(logger, "ts", log.DefaultTimestampUTC)
logger = log.With(logger, "caller", log.DefaultCaller)
logger = level.NewFilter(logger, level.AllowAll())

// Overriding the default klog with our go-kit klog implementation.
// Thus we need to pass it our go-kit logger object.
klog.SetLogger(logger)

Setting the klog's logger MUST happen at the very beginning of your program (e.g. before using the other klog functions).

Function Levels

klog	gokit
Info	Debug
InfoDepth	Debug
Infof	Debug
Infoln	Debug
InfoS	Debug
InfoSDepth	Debug
Warning	Warn
WarningDepth	Warn
Warningf	Warn
Warningln	Warn
Error	Error
ErrorDepth	Error
Errorf	Error
Errorln	Error
Exit	Error
ExitDepth	Error
Exitf	Error
Exitln	Error
Fatal	Error
FatalDepth	Error
Fatalf	Error
Fatalln	Error

This table is rather opinionated and build for use with the Kubernetes' Go client.

Disclaimer

This project doesn't aim at covering the complete klog API. That being said, it should work ok for projects that use k8s.io/client-go (like Prometheus for instance).

Limitations

The module implements the klog.Context(context.Context), klog.Background() and klog.TODO() functions but they all return a zero-value Logger which drops all log messages.

License

Apache License 2.0, see LICENSE.