From 9963ba977187799ee1d67df6a17ef4fe6b0772a3 Mon Sep 17 00:00:00 2001
From: Joao Morais <jcmoraisjr@gmail.com>
Date: Wed, 1 May 2024 18:52:13 -0300
Subject: [PATCH] fix label generation for node discovery

A set of labels are used to find all the nodes of a cluster of ingress
controllers. The controller instance running the code takes its own
set of labels and use it to find the others via apiserver. The set of
labels has, however, some labels that uniquely identify a pod, like
pod-template-hash created by the ReplicaSet, making the node discovery
to discover only one node, the one being running. On shutdowns, this
makes the controller to incorrectly think it is running alone, leading
to remove the status of all the ingress resources. Removing all the
well-known label keys that uniquely identifies a pod solves this issue.
---
 pkg/common/k8s/main.go                  | 12 ++++++++++--
 pkg/controller/services/svcstatusing.go |  9 ++++++++-
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/pkg/common/k8s/main.go b/pkg/common/k8s/main.go
index c846405da..7a427ad00 100644
--- a/pkg/common/k8s/main.go
+++ b/pkg/common/k8s/main.go
@@ -91,10 +91,18 @@ func GetPodDetails(kubeClient clientset.Interface) (*PodInfo, error) {
 		return nil, fmt.Errorf("unable to get POD information")
 	}
 
+	podNodeIP := GetNodeIP(kubeClient, pod.Spec.NodeName, true)
+	podLabels := pod.GetLabels()
+
+	// remove labels that uniquely identify a pod
+	delete(podLabels, "controller-revision-hash")
+	delete(podLabels, "pod-template-generation")
+	delete(podLabels, "pod-template-hash")
+
 	return &PodInfo{
 		Name:      podName,
 		Namespace: podNs,
-		NodeIP:    GetNodeIP(kubeClient, pod.Spec.NodeName, true),
-		Labels:    pod.GetLabels(),
+		NodeIP:    podNodeIP,
+		Labels:    podLabels,
 	}, nil
 }
diff --git a/pkg/controller/services/svcstatusing.go b/pkg/controller/services/svcstatusing.go
index a69daaed4..e3417d4d1 100644
--- a/pkg/controller/services/svcstatusing.go
+++ b/pkg/controller/services/svcstatusing.go
@@ -253,10 +253,17 @@ func (s *svcStatusIng) getControllerPodList(ctx context.Context) ([]api.Pod, err
 	if err := s.cli.Get(ctx, types.NamespacedName{Namespace: s.cfg.PodNamespace, Name: s.cfg.PodName}, &pod); err != nil {
 		return nil, err
 	}
+
+	// remove labels that uniquely identify a pod
+	podLabels := pod.GetLabels()
+	delete(podLabels, "controller-revision-hash")
+	delete(podLabels, "pod-template-generation")
+	delete(podLabels, "pod-template-hash")
+
 	// read all controller's pod
 	podList := api.PodList{}
 	if err := s.cli.List(ctx, &podList, &client.ListOptions{
-		LabelSelector: labels.SelectorFromSet(pod.GetLabels()),
+		LabelSelector: labels.SelectorFromSet(podLabels),
 		Namespace:     s.cfg.PodNamespace,
 	}); err != nil {
 		return nil, err