otel

phuslog OpenTelemetry Logs Adapter

This submodule is for applications that want OpenTelemetry Logs API compatibility while keeping phuslog JSON as the log output format. It bridges OpenTelemetry Logs API records to github.com/phuslu/log, preserving common OpenTelemetry metadata such as severity, trace context, scope, and attributes as JSON fields.

It is not an OTLP exporter and does not implement the OpenTelemetry SDK pipeline. To send logs to an OpenTelemetry Collector, write phuslog JSON to stdout or a file and configure a Collector receiver, or use an OpenTelemetry SDK exporter separately.

package main

import (
	"context"

	phuslog "github.com/phuslu/log"
	phuslogotel "github.com/phuslu/log/otel"
	otellog "go.opentelemetry.io/otel/log"
)

func main() {
	var logger otellog.Logger = phuslogotel.Logger{
		Log: phuslog.Logger{
			Level: phuslog.InfoLevel,
		},
	}

	var record otellog.Record
	record.SetSeverity(otellog.SeverityInfo)
	record.SetBody(otellog.StringValue("hello from otel"))
	record.AddAttributes(otellog.String("component", "worker"))

	logger.Emit(context.Background(), record)
}

Use LoggerProvider when integrating with OpenTelemetry code that expects a log.LoggerProvider.

Use StdoutExporter when the output should be standard OpenTelemetry stdout log JSON instead of phuslog flat JSON:

package main

import (
	"context"
	"os"

	phuslogotel "github.com/phuslu/log/otel"
	"go.opentelemetry.io/otel/log/global"
	otellog "go.opentelemetry.io/otel/log"
	sdklog "go.opentelemetry.io/otel/sdk/log"
)

func main() {
	ctx := context.Background()
	exporter := &phuslogotel.StdoutExporter{Writer: os.Stdout}
	provider := sdklog.NewLoggerProvider(
		sdklog.WithProcessor(sdklog.NewBatchProcessor(exporter)),
	)
	defer provider.Shutdown(ctx)
	global.SetLoggerProvider(provider)

	logger := global.Logger("example")
	var record otellog.Record
	record.SetSeverity(otellog.SeverityInfo)
	record.SetBody(otellog.StringValue("hello from otel stdout"))
	record.AddAttributes(otellog.String("component", "worker"))

	logger.Emit(ctx, record)
}

Performance

Benchmarks compare the phuslog flat JSON adapter, the phuslog stdout exporter, and the official OpenTelemetry stdoutlog exporter, all writing equivalent nested log records as JSON to io.Discard. The official stdoutlog benchmark is an exporter-only lower bound; it skips the SDK logger and processor path. In this nested-record benchmark, the direct adapter path runs with 0 B/op and 0 allocs/op.

Measured with Go 1.26.2 on linux/arm64:

go test -run=^$ -bench='Benchmark(PhusluLoggerEmitNestedValues|PhusluStdoutExporterNestedValues|OTelStdoutExporterNestedValues)$' -benchmem -count=10

Representative result:

BenchmarkPhusluLoggerEmitNestedValues-4         1219254    999.2 ns/op     0 B/op   0 allocs/op
BenchmarkPhusluStdoutExporterNestedValues-4      400059   2858 ns/op    1264 B/op   5 allocs/op
BenchmarkOTelStdoutExporterNestedValues-4         64694  18546 ns/op    2178 B/op  41 allocs/op

Across 10 runs: