clog, fmt.Format semantics and slog access via context

The log/slog package is very well-designed and extendable, but it's not fully context-oriented. You'll need to either pass the logger around everywhere or use a global logger even if the code where you use it is fully context-oriented. Furthermore, it doesn't provide the very convenient fmt.Sprintf semantics for logging.

clog

The clog package provides the following functionality:

• A WithLogger function that returns a context with the logger attached.
• Global functions needed to use the logger, such as Info(context.Context, string, ...any) and With(context.Context, ...any) context.Context
• Functions like Errorf, Warningf, Infof, Debugf and Tracef that understans standard fmt.Format semantics.
• A CondensedHandler that outputs a condensed version of the log message, using key=value pairs only for extra slog.Attr values. This handler also defers the creation of the log message when the message stems from a function that uses fmt.Format semantics so that it is produced with fmt.Fprintf on an internal buffer.

The clog package has no external dependencies.

Usage

package main
import (
	"context"
	"log/slog"
	"os"

	"github.com/telepresenceio/clog"
	"github.com/telepresenceio/clog/handler"
)

func main() {
	h := handler.NewText(
		handler.Output(os.Stdout), handler.TimeFormat("15:04:05.0000"), handler.EnabledLevel(clog.LevelDebug))
	ctx := clog.WithLogger(context.Background(), slog.New(h))
	clog.Infof(ctx, "Hello, %s!", "world")
}