rlog

rlog

rlog is a minimalistic, asynchronous logger for Go services that prefer best-effort throughput over perfect durability. It focuses on simplicity: format the message once, push it to a buffered channel, and let background writers take care of I/O.

Highlights

• Structured around a tiny LogSink interface; mix and match sinks as needed.
• Console writer with optional ANSI colouring for warnings and errors.
• Buffered file writer with rotation and configurable size limits.
• Built-in presets surface audit-level events on the console so operators don't miss key milestones.
• Global helpers (rlog.Infof, rlog.Warnf, …) for applications that want a ready-to-use default logger.
• Designed to keep the main code path non-blocking during normal operation.

Quick Start

package main

import (
	"time"

	"github.com/gavriva/rlog"
)

func main() {
	logger := rlog.NewLogger(
		rlog.NewBufferedSink(128, rlog.NewFileWriter("service", 200*1024*1024)),
		true, // include caller file:line
	)
	defer logger.Close()

	logger.Infof("service started")
	time.Sleep(time.Second)
	logger.Warnf("downstream latency exceeded: %s", time.Second)
}

Log levels

Built-in sinks

• ConsoleWriter — prints to STDOUT, optionally colourised.
• FileWriter — rotates log files (app.log, app.1.log, app.2.log) once the size limit is reached.
• BufferedSink — decouples the caller from I/O by dispatching logs through a bounded channel and periodic flushes.
• MultiWriter — mirrors logs to two sinks (for example console + file). Combine sinks to match your deployment scenario:

logger := rlog.NewLogger(
	rlog.NewMultiWriter(
		rlog.NewConsoleWriter(rlog.Audit),
		rlog.NewBufferedSink(256, rlog.NewFileWriter("", 1e8)),
	),
	true,
)

Global logger

For applications that prefer a singleton logger, call one of the presets:

rlog.EnableDefaultLoggerForService()
defer rlog.Close()
rlog.Infof("ready to accept requests")

Remember to call rlog.Close() during shutdown to flush buffered output.

Design notes & trade-offs

• BufferedSink uses a bounded channel. When the buffer is saturated the call to Log blocks until space is available. Pick a size that fits your burst rate to keep the hot path non-blocking.
• There is no guarantee that every record is written before an unexpected process crash. If durable logging is critical, pair rlog with an external collector or append-only sink.
• File rotation keeps the three most recent log files by default.

License

MIT — see LICENSE for details.