Avoid applying updates on Ingress Controller shutdown

cmd/nginx-ingress/main.go

@@ -323,6 +323,7 @@
 NICVersion: version,
 DynamicWeightChangesReload: *enableDynamicWeightChangesReload,
 InstallationFlags: parsedFlags,
+ShuttingDown: false,
 }
 
 lbc := k8s.NewLoadBalancerController(lbcInput)
@@ -816,6 +817,7 @@
 nl.Fatalf(lbc.Logger, "AppProtectDosAgent command exited unexpectedly with status: %v", err)
 case <-signalChan:
 nl.Info(lbc.Logger, "Received SIGTERM, shutting down")
+lbc.ShuttingDown = true
 lbc.Stop()
 nginxManager.Quit()
 <-cpcfg.nginxDone

internal/k8s/configmap.go

@@ -82,6 +82,11 @@
 key := task.Key
 nl.Debugf(lbc.Logger, "Syncing configmap %v", key)
 
+if key == lbc.mgmtConfigMapName && lbc.isPodMarkedForDeletion() {
+nl.Debugf(lbc.Logger, "Pod is shutting down, skipping management ConfigMap sync")
+return
+}
+
 switch key {
 case lbc.nginxConfigMapName:
 obj, configExists, err := lbc.configMapLister.GetByKey(key)
@@ -120,6 +125,9 @@
 nl.Debugf(lbc.Logger, "Skipping ConfigMap update because batch sync is on")
 return
 }
-
+if err := lbc.ctx.Err(); err != nil {
+nl.Debugf(lbc.Logger, "Context canceled, skipping ConfigMap sync for %v: %v", task.Key, err)
+return
+}
 lbc.updateAllConfigs()
 }

internal/k8s/controller.go

@@ -185,6 +185,7 @@ type LoadBalancerController struct {
 weightChangesDynamicReload bool
 nginxConfigMapName string
 mgmtConfigMapName string
+ShuttingDown bool
 }
 
 var keyFunc = cache.DeletionHandlingMetaNamespaceKeyFunc
@@ -241,6 +242,7 @@ type NewLoadBalancerControllerInput struct {
 NICVersion string
 DynamicWeightChangesReload bool
 InstallationFlags []string
+ShuttingDown bool
 }
 
 // NewLoadBalancerController creates a controller
@@ -286,6 +288,7 @@ func NewLoadBalancerController(input NewLoadBalancerControllerInput) *LoadBalanc
 weightChangesDynamicReload: input.DynamicWeightChangesReload,
 nginxConfigMapName: input.ConfigMaps,
 mgmtConfigMapName: input.MGMTConfigMap,
+ShuttingDown: input.ShuttingDown,
 }
 
 lbc.syncQueue = newTaskQueue(lbc.Logger, lbc.sync)
@@ -3649,3 +3652,20 @@ func (lbc *LoadBalancerController) createCombinedDeploymentHeadlessServiceName()
 combinedDeployment := fmt.Sprintf("%s-%s", name, strings.ToLower(owner.Kind))
 return combinedDeployment
 }
+
+func (lbc *LoadBalancerController) isPodMarkedForDeletion() bool {
+// Check if the controller is shutting down
+if lbc.ShuttingDown {
+nl.Debugf(lbc.Logger, "SIGTERM already received, controller is shutting down")
+return true
+}
+podName := os.Getenv("POD_NAME")
+podNamespace := os.Getenv("POD_NAMESPACE")
+pod, err := lbc.client.CoreV1().Pods(podNamespace).Get(context.Background(), podName, meta_v1.GetOptions{})
+if err == nil && pod.DeletionTimestamp != nil {
+nl.Debugf(lbc.Logger, "Pod %s/%s is marked for deletion", podNamespace, podName)
+return true
+}
+
+return false
+}

internal/k8s/controller_test.go

@@ -4,6 +4,7 @@ import (
 "context"
 "errors"
 "fmt"
+"os"
 "reflect"
 "sort"
 "strings"
@@ -3639,3 +3640,87 @@ func TestCreateIngressExWithZoneSync(t *testing.T) {
 }
 }
 }
+
+func TestIsPodMarkedForDeletion(t *testing.T) {
+t.Parallel()
+
+logger := nl.LoggerFromContext(context.Background())
+
+tests := []struct {
+name string
+shutdownFlag bool
+envPodName string
+envPodNamespace string
+podExists bool
+podHasTimestamp bool
+expectedResult bool
+}{
+{
+name: "controller is shutting down",
+shutdownFlag: true,
+expectedResult: true,
+},
+{
+name: "pod exists with deletion timestamp",
+envPodName: "test-pod",
+envPodNamespace: "test-namespace",
+podExists: true,
+podHasTimestamp: true,
+expectedResult: true,
+},
+{
+name: "pod exists without deletion timestamp",
+envPodName: "test-pod",
+envPodNamespace: "test-namespace",
+podExists: true,
+podHasTimestamp: false,
+expectedResult: false,
+},
+}
+
+for _, test := range tests {
+test := test
+t.Run(test.name, func(t *testing.T) {
+client := fake.NewSimpleClientset()
+
+err := os.Setenv("POD_NAME", test.envPodName)
+if err != nil {
+t.Fatalf("Failed to set POD_NAME environment variable: %v", err)
+}
+err = os.Setenv("POD_NAMESPACE", test.envPodNamespace)
+if err != nil {
+t.Fatalf("Failed to set POD_NAMESPACE environment variable: %v", err)
+}
+if test.podExists {
+pod := &api_v1.Pod{
+ObjectMeta: meta_v1.ObjectMeta{
+Name: test.envPodName,
+Namespace: test.envPodNamespace,
+},
+}
+
+if test.podHasTimestamp {
+now := meta_v1.Now()
+pod.DeletionTimestamp = &now
+}
+
+_, err := client.CoreV1().Pods(test.envPodNamespace).Create(context.Background(), pod, meta_v1.CreateOptions{})
+if err != nil {
+t.Fatalf("Error creating pod: %v", err)
+}
+}
+
+lbc := &LoadBalancerController{
+client: client,
+ShuttingDown: test.shutdownFlag,
+Logger: logger,
+}
+
+// Call the function and verify result
+result := lbc.isPodMarkedForDeletion()
+if result != test.expectedResult {
+t.Errorf("Returned %v but expected %v", result, test.expectedResult)
+}
+})
+}
+}