fix: use interruptionQueue Helm value for Karpenter >= v0.33.0

pkg/karpenter/karpenter.go

@@ -30,6 +30,7 @@ const (
 	serviceAccountName       = "name"
 	settings                 = "settings"
 	interruptionQueueName    = "interruptionQueueName"
+	interruptionQueue        = "interruptionQueue"
 )
 
 // Options contains values which Karpenter uses to configure the installation.
@@ -72,29 +73,50 @@ func (k *Installer) Install(ctx context.Context, serviceAccountRoleARN string, i
 		serviceAccountName: DefaultServiceAccountName,
 	}
 
+	settingsValues := map[string]interface{}{
+		defaultInstanceProfile: instanceProfileName,
+		clusterName:            k.ClusterConfig.Metadata.Name,
+		clusterEndpoint:        k.ClusterConfig.Status.Endpoint,
+	}
+
+	// The Karpenter chart renamed the interruption queue Helm value when it
+	// flattened `settings`: charts before v0.33.0 read
+	// `settings.aws.interruptionQueueName`, while the flattened layout reads
+	// `settings.interruptionQueue`. A flattened chart silently ignores the old
+	// spelling, which leaves INTERRUPTION_QUEUE unset on the Karpenter pod and
+	// disables spot interruption handling without reporting an error.
+	version := k.ClusterConfig.Karpenter.Version
+	compareVersions, err := utils.CompareVersions(version, "0.33.0")
+	legacyChart := err == nil && compareVersions < 0
+
+	// Only advertise the interruption queue when eksctl actually provisioned it.
+	// pkg/cfn/builder creates the SQS queue -- and grants the controller role
+	// sqs:ReceiveMessage on it -- only when withSpotInterruptionQueue is enabled,
+	// so sending the name unconditionally would point Karpenter at a queue that
+	// does not exist and that it has no permission to poll.
+	queueEnabled := api.IsEnabled(k.ClusterConfig.Karpenter.WithSpotInterruptionQueue)
+
+	if legacyChart {
+		if queueEnabled {
+			settingsValues[interruptionQueueName] = k.ClusterConfig.Metadata.Name
+		}
+		settingsValues = map[string]interface{}{
+			aws: settingsValues,
+		}
+	} else if queueEnabled {
+		settingsValues[interruptionQueue] = k.ClusterConfig.Metadata.Name
+	}
+
 	values := map[string]interface{}{
 		clusterName:     k.ClusterConfig.Metadata.Name,
 		clusterEndpoint: k.ClusterConfig.Status.Endpoint,
 		aws: map[string]interface{}{
 			defaultInstanceProfile: instanceProfileName,
 		},
-		settings: map[string]interface{}{
-			defaultInstanceProfile: instanceProfileName,
-			clusterName:            k.ClusterConfig.Metadata.Name,
-			clusterEndpoint:        k.ClusterConfig.Status.Endpoint,
-			interruptionQueueName:  k.ClusterConfig.Metadata.Name,
-		},
+		settings:       settingsValues,
 		serviceAccount: serviceAccountMap,
 	}
 
-	version := k.ClusterConfig.Karpenter.Version
-	compareVersions, err := utils.CompareVersions(version, "0.33.0")
-	if err == nil && compareVersions < 0 {
-		values[settings] = map[string]interface{}{
-			aws: values[settings],
-		}
-	}
-
 	registryClient, err := registry.NewClient(
 		registry.ClientOptEnableCache(true),
 	)

pkg/karpenter/karpenter_test.go

@@ -30,6 +30,9 @@ var _ = Describe("Install", func() {
 				Version:                "0.15.3",
 				CreateServiceAccount:   api.Disabled(),
 				DefaultInstanceProfile: nil,
+				// The queue name is only sent when eksctl provisioned the queue,
+				// so the specs that assert on it enable it explicitly.
+				WithSpotInterruptionQueue: api.Enabled(),
 			}
 			cfg.Status = &api.ClusterStatus{
 				Endpoint: "https://endpoint.com",
@@ -90,10 +93,55 @@ var _ = Describe("Install", func() {
 					defaultInstanceProfile: "dummy",
 					clusterName:            cfg.Metadata.Name,
 					clusterEndpoint:        cfg.Status.Endpoint,
-					interruptionQueueName:  cfg.Metadata.Name,
+					// The flattened Karpenter chart names this value
+					// "interruptionQueue", not "interruptionQueueName" --
+					// see charts/karpenter/values.yaml from v0.32.0 onwards.
+					// Asserted as a literal rather than via a constant so the
+					// test pins the key the chart actually reads.
+					"interruptionQueue": cfg.Metadata.Name,
 				},
 			}
 			Expect(opts.Values[settings]).To(Equal(values[settings]))
+			// The legacy specs assert the whole values map; do the same here so
+			// the top-level keys are guarded on the flattened path too.
+			Expect(opts.Values[aws]).To(Equal(map[string]interface{}{defaultInstanceProfile: "dummy"}))
+			Expect(opts.Values[clusterName]).To(Equal(cfg.Metadata.Name))
+			Expect(opts.Values[clusterEndpoint]).To(Equal(cfg.Status.Endpoint))
+		})
+
+		When("withSpotInterruptionQueue is disabled", func() {
+
+			BeforeEach(func() {
+				cfg.Karpenter.WithSpotInterruptionQueue = api.Disabled()
+			})
+
+			// pkg/cfn/builder only creates the SQS queue, and only grants the
+			// controller role sqs:ReceiveMessage on it, when the queue is
+			// enabled. Advertising a queue name in either chart layout would
+			// point Karpenter at a queue that does not exist and that it
+			// cannot poll.
+			It("omits the queue name from the legacy settings.aws values", func() {
+				Expect(installerUnderTest.Install(context.Background(), "dummy", "dummy")).To(Succeed())
+				_, opts := fakeHelmInstaller.InstallChartArgsForCall(0)
+				Expect(opts.Values[settings]).To(Equal(map[string]interface{}{
+					aws: map[string]interface{}{
+						defaultInstanceProfile: "dummy",
+						clusterName:            cfg.Metadata.Name,
+						clusterEndpoint:        cfg.Status.Endpoint,
+					},
+				}))
+			})
+
+			It("omits the queue name from the flattened settings values", func() {
+				installerUnderTest.ClusterConfig.Karpenter.Version = "0.33.0"
+				Expect(installerUnderTest.Install(context.Background(), "dummy", "dummy")).To(Succeed())
+				_, opts := fakeHelmInstaller.InstallChartArgsForCall(0)
+				Expect(opts.Values[settings]).To(Equal(map[string]interface{}{
+					defaultInstanceProfile: "dummy",
+					clusterName:            cfg.Metadata.Name,
+					clusterEndpoint:        cfg.Status.Endpoint,
+				}))
+			})
 		})
 
 		When("install chart fails", func() {