event_filter.go

/*
(c) Copyright IBM Corp. 2025

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package controllers

import (
	"time"

	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/event"
	"sigs.k8s.io/controller-runtime/pkg/predicate"

	instanav1 "github.com/instana/instana-agent-operator/api/v1"
	"github.com/instana/instana-agent-operator/pkg/collections/list"
	instanaclient "github.com/instana/instana-agent-operator/pkg/k8s/client"
)

func wasModifiedByOther(objectNew client.Object, objectOld client.Object) bool {
	var lastModifiedBySelf time.Time

	for _, mfe := range objectNew.GetManagedFields() {
		if mfe.Manager == instanaclient.FieldOwnerName {
			if mfe.Time == nil {
				continue
			}
			lastModifiedBySelf = mfe.Time.Time
			break
		}
	}

	if lastModifiedBySelf.IsZero() {
		return true
	}

	for _, mfe := range objectNew.GetManagedFields() {
		if mfe.Manager == instanaclient.FieldOwnerName {
			continue
		} else if mfe.Time == nil && !list.NewDeepContainsElementChecker(objectOld.GetManagedFields()).Contains(mfe) {
			return true
		} else if lastModifiedBySelf.Before(mfe.Time.Time) {
			return true
		}
	}

	return false
}

// Create generic filter for all events, that removes some chattiness mainly when only the Status field has been updated.
func filterPredicate() predicate.Predicate {
	return predicate.Funcs{
		CreateFunc: func(createEvent event.CreateEvent) bool {
			switch createEvent.Object.(type) {
			case *instanav1.InstanaAgent:
				return true
			default:
				return false
			}
		},
		UpdateFunc: func(e event.UpdateEvent) bool {
			switch e.ObjectOld.(type) {
			case *instanav1.InstanaAgent:
				return e.ObjectOld.GetGeneration() != e.ObjectNew.GetGeneration()
			default:
				return wasModifiedByOther(e.ObjectNew, e.ObjectOld)
			}
		},
		DeleteFunc: func(e event.DeleteEvent) bool {
			switch e.Object.(type) {
			case *instanav1.InstanaAgent:
				return !e.DeleteStateUnknown
			default:
				return true
			}
		},
	}
}

func filterPredicateRemote() predicate.Predicate {
	return predicate.Funcs{
		CreateFunc: func(createEvent event.CreateEvent) bool {
			switch createEvent.Object.(type) {
			case *instanav1.InstanaAgentRemote:
				return true
			default:
				return false
			}
		},
		UpdateFunc: func(e event.UpdateEvent) bool {
			switch e.ObjectOld.(type) {
			case *instanav1.InstanaAgentRemote:
				return e.ObjectOld.GetGeneration() != e.ObjectNew.GetGeneration()
			default:
				return wasModifiedByOther(e.ObjectNew, e.ObjectOld)
			}
		},
		DeleteFunc: func(e event.DeleteEvent) bool {
			switch e.Object.(type) {
			case *instanav1.InstanaAgentRemote:
				return !e.DeleteStateUnknown
			default:
				return true
			}
		},
	}
}