otelslog

Overview ¶

Package otelslog provides Handler, an slog.Handler implementation, that can be used to bridge between the log/slog API and OpenTelemetry.

Record Conversion ¶

The slog.Record are converted to OpenTelemetry log.Record in the following way:

• Time is set as the Timestamp.
• Message is set as the Body using a log.StringValue.
• Level is transformed and set as the Severity. The SeverityText is not set.
• PC is dropped.
• Attr are transformed and set as the Attributes.

The Level is transformed by using the static offset to the OpenTelemetry Severity types. For example:

• slog.LevelDebug is transformed to log.SeverityDebug
• slog.LevelInfo is transformed to log.SeverityInfo
• slog.LevelWarn is transformed to log.SeverityWarn
• slog.LevelError is transformed to log.SeverityError

Attribute values are transformed based on their slog.Kind:

• slog.KindAny are transformed to log.StringValue. The value is encoded using fmt.Sprintf.
• slog.KindBool are transformed to log.BoolValue directly.
• slog.KindDuration are transformed to log.Int64Value as nanoseconds.
• slog.KindFloat64 are transformed to log.Float64Value directly.
• slog.KindInt64 are transformed to log.Int64Value directly.
• slog.KindString are transformed to log.StringValue directly.
• slog.KindTime are transformed to log.Int64Value as nanoseconds since the Unix epoch.
• slog.KindUint64 are transformed to log.Int64Value using int64 conversion.
• slog.KindGroup are transformed to log.MapValue using appropriate transforms for each group value.
• slog.KindLogValuer the value is resolved and then transformed.

package main

import (
	"go.opentelemetry.io/contrib/bridges/otelslog"
	"go.opentelemetry.io/otel/log/noop"
)

func main() {
	// Use a working LoggerProvider implementation instead e.g. using go.opentelemetry.io/otel/sdk/log.
	provider := noop.NewLoggerProvider()

	// Create an *slog.Logger and use it in your application.
	otelslog.NewLogger("my/pkg/name", otelslog.WithLoggerProvider(provider))
}

Output: