Specify and clarify root cause of issue 4241

controller/controller.go

@@ -210,9 +210,12 @@ func (c *Controller) RunOnce(ctx context.Context) error {
 		return err
 	}
 
-	//records = endpoint.RemoveDuplicates(records)
-	//This deduplication could be a different but valid solution
+	records = endpoint.RemoveDuplicates(records)
+	//This deduplication seems to be the a good fit
+	//Duplicated endpoints were living on this variable
+	//In all versions for the overlapping zones
 	//With this in place the change on plan.go is not needed
+	//Also it saves some rounds of cpu
 	//Keeping this here until we decide what's best
 	registryEndpointsTotal.Set(float64(len(records)))
 	regARecords, regAAAARecords := countAddressRecords(records)

endpoint/endpoint.go

@@ -345,6 +345,8 @@ type DNSEndpointList struct {
 }
 
 // RemoveDuplicates returns a slice holding the unique endpoints.
+// This function doesn't contemplate the Targets of an Endpoint
+// as part of the primary Key
 func RemoveDuplicates(endpoints []*Endpoint) []*Endpoint {
 	visited := make(map[EndpointKey]struct{})
 	result := []*Endpoint{}

plan/plan.go

@@ -170,6 +170,20 @@ func (p *Plan) Calculate() *Plan {
 	if p.DomainFilter == nil {
 		p.DomainFilter = endpoint.MatchAllDomainFilters(nil)
 	}
+	//  Root cause of the issue:
+	//	Behavior on 0.14.0 on Deletes
+	//	------------------------------------------------------------------------------------------------------
+	//	DNSName          | Current record                                      | Desired Records (Candidate) |
+	//	------------------------------------------------------------------------------------------------------
+	//	dnsname.zone.com |[dnsname.zone.com IN A]dnsname.zone.com IN A (dup ep)| []                          |
+	//	------------------------------------------------------------------------------------------------------
+	//
+	//	Behavior on 0.13.6 on Deletes
+	//	------------------------------------------------------------------------------------------------------
+	//	DNSName          | Current record                                      | Desired Records (Candidate) |
+	//	------------------------------------------------------------------------------------------------------
+	//	dnsname.zone.com | [dnsname.zone.com IN CNAME ]                        | []                          |
+	//	------------------------------------------------------------------------------------------------------
 
 	for _, current := range filterRecordsForPlan(p.Current, p.DomainFilter, p.ManagedRecords, p.ExcludeRecords) {
 		t.addCurrent(current)
@@ -252,10 +266,11 @@ func (p *Plan) Calculate() *Plan {
 	// filter out updates this external dns does not have ownership claim over
 	if p.OwnerID != "" {
 		changes.Delete = endpoint.FilterEndpointsByOwnerID(p.OwnerID, changes.Delete)
-		// Remove duplicated endpoints generated by plan.go on Line 196
-		changes.Delete = endpoint.RemoveDuplicates(changes.Delete)
+		// Remove duplicated endpoints generated by plan.go on Line 210
+		// changes.Delete = endpoint.RemoveDuplicates(changes.Delete)
 		// This was not needed on version 0.13.6, but it seems like
 		// the old function/code had the ability of removing duplicated endpoints
+		// While the filterRecordsForPlan and addCurrent functions were running
 		changes.UpdateOld = endpoint.FilterEndpointsByOwnerID(p.OwnerID, changes.UpdateOld)
 		changes.UpdateNew = endpoint.FilterEndpointsByOwnerID(p.OwnerID, changes.UpdateNew)
 	}