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 +73,39 @@ 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")
+	if err == nil && compareVersions < 0 {
+		settingsValues[interruptionQueueName] = k.ClusterConfig.Metadata.Name
+		settingsValues = map[string]interface{}{
+			aws: settingsValues,
+		}
+	} else {
+		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

@@ -90,7 +90,12 @@ 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]))