trace.go

// Copyright 2022 The zapcl Authors
// SPDX-License-Identifier: BSD-3-Clause

package zapcl

import (
	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"

	"github.com/zchee/zapcl/pkg/monitoredresource"
)

const (
	// TraceKey is the resource name of the trace associated with the log entry if any. For more information.
	//
	// trace field:
	// - https://cloud.google.com/logging/docs/structured-logging#special-payload-fields
	// - https://cloud.google.com/logging/docs/reference/v2/rest/v2/LogEntry#FIELDS.trace
	TraceKey = "logging.googleapis.com/trace"

	// SpanKey is the span ID within the trace associated with the log entry. For more information.
	//
	// spanId field:
	// - https://cloud.google.com/logging/docs/structured-logging#special-payload-fields
	// - https://cloud.google.com/logging/docs/reference/v2/rest/v2/LogEntry#FIELDS.span_id
	SpanKey = "logging.googleapis.com/spanId"

	// TraceSampledKey is the value of this field must be either true or false. For more information.
	//
	// trace_sampled field:
	// - https://cloud.google.com/logging/docs/structured-logging#special-payload-fields
	// - https://cloud.google.com/logging/docs/reference/v2/rest/v2/LogEntry#FIELDS.trace_sampled
	TraceSampledKey = "logging.googleapis.com/trace_sampled"
)

const (
	traceKeyPrefix = "projects/"
	traceKeySuffix = "/traces/"
)

// TraceField adds the correct Cloud Logging "trace", "span", "trace_sampled" fields from ctx.
//
// https://cloud.google.com/logging/docs/agent/logging/configuration#special-fields
func TraceField(traceID, spanID string, isSampled bool) []zapcore.Field {
	return []zapcore.Field{
		zap.String(TraceKey, traceKeyPrefix+monitoredresource.ResourceDetector.ProjectID()+traceKeySuffix+traceID),
		zap.String(SpanKey, spanID),
		zap.Bool(TraceSampledKey, isSampled),
	}
}