The annotations-filter startup parameter is not used for configmap, rbac, service, serviceaccount resources.

[chinaran]

Component(s)

collector

What happened?

Description

annotations-filter has a default configuration that filters kubectl.kubernetes.io/last-applied-configuration.

Steps to Reproduce

deploy a otel-collector instance.

Expected Result

None of the resources installed by opentelemetry-operator have kubectl.kubernetes.io/last-applied-configuration annotations.

Actual Result

The configmap, rbac, service, serviceaccount resources are annotated kubectl.kubernetes.io/last-applied-configuration.

Kubernetes Version

v1.29.2

Operator version

v0.104.0

Collector version

v0.104.0

Environment information

Environment

OS: MacOS Kind

Log output

No response

Additional context

I found that the hpa resource filters the kubectl.kubernetes.io/last-applied-configuration annotation.
Reference: https://github.com/open-telemetry/opentelemetry-operator/blob/v0.104.0/internal/manifests/collector/horizontalpodautoscaler.go# L31.

annotations, err := manifestutils.Annotations(params.OtelCol, params.Config.AnnotationsFilter())
if err != nil {
	return nil, err
}

When I try to fix this issue using similar code, I have the following two queries:

1. whether Prometheus annotations should be added only in PodAnnotations.

2. Should the opentelemetry-operator-config/sha256 annotation be added to all resources.

// Annotations return the annotations for OpenTelemetryCollector pod.
func Annotations(instance v1beta1.OpenTelemetryCollector, filterAnnotations []string) (map[string]string, error) {
	// new map every time, so that we don't touch the instance's annotations
	annotations := map[string]string{}

	// Enable Prometheus annotations by default if DisablePrometheusAnnotations is nil or true
	if !instance.Spec.Observability.Metrics.DisablePrometheusAnnotations {
		// Set default Prometheus annotations
		annotations["prometheus.io/scrape"] = "true"
		annotations["prometheus.io/port"] = "8888"
		annotations["prometheus.io/path"] = "/metrics"
	}

	// allow override of prometheus annotations
	if nil != instance.ObjectMeta.Annotations {
		for k, v := range instance.ObjectMeta.Annotations {
			if !IsFilteredSet(k, filterAnnotations) {
				annotations[k] = v
			}
		}
	}

	hash, err := GetConfigMapSHA(instance.Spec.Config)
	if err != nil {
		return nil, err
	}

	// make sure sha256 for configMap is always calculated
	annotations["opentelemetry-operator-config/sha256"] = hash

	return annotations, nil
}

[jaronoff97]

@chinaran thanks for opening this! To answer your questions:

1. I think only pod annotations needs the prometheus annotation filtering code you referenced
2. I do think there's value in having the config hash for each generated resource, it allows us to restart the collector pod when a config change has been made (see the original issue here)

[chinaran]

@jaronoff97 Thank you for your answer.
Based on these two conclusions, I submitted a PR: #3163.
Please check it out.