feat(aws-neptune): add autoMinorVersionUpgrade to cluster props

packages/@aws-cdk/aws-neptune/README.md

@@ -125,3 +125,17 @@ const replica1 = new neptune.DatabaseInstance(this, 'Instance', {
   instanceType: neptune.InstanceType.R5_LARGE
 });
 ```
+
+## Automatic minor version upgrades
+
+By setting `autoMinorVersionUpgrade` to true, Neptune will automatically update 
+the engine of the entire cluster to the latest minor version after a stabilization 
+window of 2 to 3 weeks. 
+
+```ts
+new neptune.DatabaseCluster(stack, 'Cluster', {
+      vpc,
+      instanceType: InstanceType.R5_LARGE,
+      autoMinorVersionUpgrade: true
+    });
+```

packages/@aws-cdk/aws-neptune/lib/cluster.ts

@@ -226,6 +226,14 @@ export interface DatabaseClusterProps {
    * @default - Retain cluster.
    */
   readonly removalPolicy?: RemovalPolicy
+
+  /**
+   * If set to true, Neptune will automatically update the engine of the entire
+   * cluster to the latest minor version after a stabilization window of 2 to 3 weeks.
+   *
+   * @default - false
+   */
+  readonly autoMinorVersionUpgrade?: boolean;
 }
 
 /**
@@ -513,6 +521,7 @@ export class DatabaseCluster extends DatabaseClusterBase implements IDatabaseClu
         // Instance properties
         dbInstanceClass: props.instanceType._instanceType,
         dbParameterGroupName: props.parameterGroup?.parameterGroupName,
+        autoMinorVersionUpgrade: props.autoMinorVersionUpgrade === true,
       });
 
       // We must have a dependency on the NAT gateway provider here to create

packages/@aws-cdk/aws-neptune/test/cluster.test.ts

@@ -523,6 +523,46 @@ describe('DatabaseCluster', () => {
     // THEN
     expect(() => { cluster.grantConnect(role); }).toThrow(/Cannot grant connect when IAM authentication is disabled/);
   });
+
+  test('autoMinorVersionUpgrade is enabled when configured', () => {
+
+    // GIVEN
+    const stack = testStack();
+    const vpc = new ec2.Vpc(stack, 'VPC');
+
+    // WHEN
+    new DatabaseCluster(stack, 'Cluster', {
+      vpc,
+      instanceType: InstanceType.R5_LARGE,
+      autoMinorVersionUpgrade: true,
+    });
+
+    // THEN
+    Template.fromStack(stack).hasResourceProperties('AWS::Neptune::DBInstance', {
+      AutoMinorVersionUpgrade: true,
+    });
+
+  });
+
+  test('autoMinorVersionUpgrade is not enabled when not configured', () => {
+
+    // GIVEN
+    const stack = testStack();
+    const vpc = new ec2.Vpc(stack, 'VPC');
+
+    // WHEN
+    new DatabaseCluster(stack, 'Cluster', {
+      vpc,
+      instanceType: InstanceType.R5_LARGE,
+    });
+
+    // THEN
+    Template.fromStack(stack).hasResourceProperties('AWS::Neptune::DBInstance', {
+      AutoMinorVersionUpgrade: false,
+    });
+
+  });
+
 });
 
 function testStack() {

packages/@aws-cdk/aws-neptune/test/integ.cluster.expected.json

@@ -491,7 +491,8 @@
         "DBInstanceClass": "db.r5.large",
         "DBClusterIdentifier": {
           "Ref": "DatabaseB269D8BB"
-        }
+        },
+        "AutoMinorVersionUpgrade": true
       },
       "DependsOn": [
         "VPCPrivateSubnet1DefaultRouteAE1D6490",

packages/@aws-cdk/aws-neptune/test/integ.cluster.ts

@@ -35,6 +35,7 @@ class TestStack extends cdk.Stack {
       clusterParameterGroup: params,
       kmsKey,
       removalPolicy: cdk.RemovalPolicy.DESTROY,
+      autoMinorVersionUpgrade: true,
     });
 
     cluster.connections.allowDefaultPortFromAnyIpv4('Open to the world');