[receiver/k8sevents] Deprecate the k8seventsreceiver

[TylerHelmuth]

Component(s)

receiver/k8sevents, receiver/k8sobjects

Describe the issue you're reporting

With the introduction of the k8sobjectsreceiver the purpose of the k8seventsreceiver is now handle by a more generic component. I propose we deprecate the k8seventsreceiver in favor of the k8sobjectsreceiver.

Work to do:

• Feature gap analysis to ensure all the functionality in k8seventsreceiver is handled by the k8sobjectsreceiver
• Fill any gaps
• Provide a migration path with a configuration that would produce the same data using k8sobjectsreceiver
• Follow deprecation process

[github-actions]

Pinging code owners for receiver/k8sevents: @dmitryax. See Adding Labels via Comments if you do not have permissions to add labels yourself.

[github-actions]

Pinging code owners for receiver/k8sobjects: @dmitryax @hvaghani221. See Adding Labels via Comments if you do not have permissions to add labels yourself.

[github-actions]

Pinging code owners:

• receiver/k8sevents: @dmitryax
• receiver/k8sobjects: @dmitryax @hvaghani221

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[TylerHelmuth]

Comparing events collected by k8sobjectsreceiver and k8seventsreceiver the biggest gap we'll need to fill is that the k8sobjectsreceiver is pretty ungraceful with the way it formats the data. The k8sobjectsreceiver puts the json event into the body of the log whereas the k8seventsreceiver attempts to build a more wholistic otlp log based on the event. Specifically the k8seventsreceiver does this:

// k8sEventToLogRecord converts Kubernetes event to plog.LogRecordSlice and adds the resource attributes.
func k8sEventToLogData(logger *zap.Logger, ev *corev1.Event) plog.Logs {
	ld := plog.NewLogs()
	rl := ld.ResourceLogs().AppendEmpty()
	sl := rl.ScopeLogs().AppendEmpty()
	lr := sl.LogRecords().AppendEmpty()

	resourceAttrs := rl.Resource().Attributes()
	resourceAttrs.EnsureCapacity(totalResourceAttributes)

	resourceAttrs.PutStr(semconv.AttributeK8SNodeName, ev.Source.Host)

	// Attributes related to the object causing the event.
	resourceAttrs.PutStr("k8s.object.kind", ev.InvolvedObject.Kind)
	resourceAttrs.PutStr("k8s.object.name", ev.InvolvedObject.Name)
	resourceAttrs.PutStr("k8s.object.uid", string(ev.InvolvedObject.UID))
	resourceAttrs.PutStr("k8s.object.fieldpath", ev.InvolvedObject.FieldPath)
	resourceAttrs.PutStr("k8s.object.api_version", ev.InvolvedObject.APIVersion)
	resourceAttrs.PutStr("k8s.object.resource_version", ev.InvolvedObject.ResourceVersion)

	lr.SetTimestamp(pcommon.NewTimestampFromTime(getEventTimestamp(ev)))

	// The Message field contains description about the event,
	// which is best suited for the "Body" of the LogRecordSlice.
	lr.Body().SetStr(ev.Message)

	// Set the "SeverityNumber" and "SeverityText" if a known type of
	// severity is found.
	if severityNumber, ok := severityMap[strings.ToLower(ev.Type)]; ok {
		lr.SetSeverityNumber(severityNumber)
		lr.SetSeverityText(ev.Type)
	} else {
		logger.Debug("unknown severity type", zap.String("type", ev.Type))
	}

	attrs := lr.Attributes()
	attrs.EnsureCapacity(totalLogAttributes)

	attrs.PutStr("k8s.event.reason", ev.Reason)
	attrs.PutStr("k8s.event.action", ev.Action)
	attrs.PutStr("k8s.event.start_time", ev.ObjectMeta.CreationTimestamp.String())
	attrs.PutStr("k8s.event.name", ev.ObjectMeta.Name)
	attrs.PutStr("k8s.event.uid", string(ev.ObjectMeta.UID))
	attrs.PutStr(semconv.AttributeK8SNamespaceName, ev.InvolvedObject.Namespace)

	// "Count" field of k8s event will be '0' in case it is
	// not present in the collected event from k8s.
	if ev.Count != 0 {
		attrs.PutInt("k8s.event.count", int64(ev.Count))
	}

	return ld
}

To generalize the function, the k8seventsreceiver takes interesting parts of the log and intelligently adds them to the resource, body, attributes, and severity. We will need to update the k8sobjectsreceiver to be this intelligent as well.

[dmitryax]

k8sobjects receiver was designed to send raw k8s objects because the OTel logs/events Spec SIG came to a conclusion to use external schemas for this kind of 3rd-party events instead of defining OTel schemas and semantic conventions for any event coming from external sources. It was decided on one of the calls. That why the k8s objects receiver was introduced to replace k8s events receiver. If we want to change it, we should start with the spec.

Also, I heard complaints from the k8s cluster users about high cardinality attributes.

[TylerHelmuth]

@dmitryax do you know if there was any OTEP or other documentation that solidified that schema decision?

Can resource attributes still be set such as k8s.pod.name using the Event's Regarding fields?

[TylerHelmuth]

@dmitryax reviewing https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/logs/event-api.md and https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/logs/semantic_conventions/events.md I don't see anything stopping us from proposing meaningful attributes and resource attributes for kubernetes events like the k8seventsreceiver implements.

[dmitryax]

I stopped attending the Log Spec SIG calls, but the last time I was there, there was an agreement to use log body for the event body and define event.domain and event.name to identify the third-party schema. @scheler, can you please update us on how this changed since that?