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multicluster: Delete headless services and endpoints when not exported (#8755) 

Closes #8475

When a headless service that was exported no longer is, we currently continue to
mirror it and its endpoints. The bug is as follows

1. The service is updated (say with `mirror.linkerd.io/exported: false`) and
   `createOrUpdateService` is called
2. The service is _not_ exported, so we queue a `RemoteServiceDeleted`
3. The `RemoteServiceDeleted` is processed and the service and its mirror
   endpoints are deleted
4. The service's endpoints are updated (on the remote cluser with the new label)
   and `handleCreateOrUpdateEndpoints` is called
5. The endpoints belong to a headless service so
   `createOrUpdateHeadlessEndpoints` is called
6. `createOrUpdateHeadlessEndpoints` recreates the just-deleted service and
   endpoints

We should stop processing the service update after `3`; the service and it's
endpionts have been properly deleted.

To fix this, we should avoid calling `handleCreateOrUpdateEndpoints` when the
new endpoints are not exported. Currently we only avoid calling this function
when both the old _and_ new endpoints are not exported.

In the case of endpoints going from being exported to be not being exported, we
don't really care about the old set's status. Therefore, to fix this bug we
remove that check and avoid calling `handleCreateOrUpdateEndpoints` when the new
set is no longer exported.

I've tested this to make sure the issue is fixed. Testing can be done
manually—which is what I did—or as explained
[here](https://github.com/linkerd/linkerd2/pull/8734#pullrequestreview-1018622066).

Signed-off-by: Kevin Leimkuhler <kleimkuhler@icloud.com>
This commit is contained in:
Kevin Leimkuhler 2022-06-28 15:04:30 -06:00 committed by GitHub
parent eadfcaa931
commit 8921c89a5f
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1 changed files with 2 additions and 11 deletions
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13
multicluster/service-mirror/cluster_watcher.go
View File

@ -836,28 +836,19 @@ func (rcsw *RemoteClusterServiceWatcher) Start(ctx context.Context) error {
rcsw.eventsQueue.Add(&OnAddEndpointsCalled{obj.(*corev1.Endpoints)})
},
// AddFunc relevant for all kind of exported endpoints
UpdateFunc: func(old, new interface{}) {
UpdateFunc: func(_, new interface{}) {
if new.(metav1.Object).GetNamespace() == kubeSystem {
return
}
epOld, ok := old.(*corev1.Endpoints)
if !ok {
rcsw.log.Errorf("error processing endpoints object: got %#v, expected *corev1.Endpoints", epOld)
return
}
epNew, ok := new.(*corev1.Endpoints)
if !ok {
rcsw.log.Errorf("error processing endpoints object: got %#v, expected *corev1.Endpoints", epNew)
return
}
if !rcsw.isExported(epOld.Labels) && !rcsw.isExported(epNew.Labels) {
if !rcsw.isExported(epNew.Labels) {
rcsw.log.Debugf("skipped processing endpoints object %s/%s: missing %s label", epNew.Namespace, epNew.Name, consts.DefaultExportedServiceSelector)
return
}
rcsw.eventsQueue.Add(&OnUpdateEndpointsCalled{epNew})
},
},