chore(ebs): set default volumeType to gp3(under feature flag) (#29934)

### Issue # (if applicable)

As the EBS console is now having `gp3` as the default volumeType, this PR set the default volumeType to gp3 if undefined under feature flag.

Closes #29931

### Reason for this change



### Description of changes



### Description of how you validated changes

I have deployed the sample below and verified the volume type is `gp3` from console.

```ts
import { Stack, App, Size, aws_ec2 as ec2 } from 'aws-cdk-lib';
import * as cxapi from 'aws-cdk-lib/cx-api';

const app = new App();

const stack = new Stack(app, 'demo-stack');

stack.node.setContext(cxapi.EBS_DEFAULT_GP3, true);

// should create a gp3 volume
new ec2.Volume(stack, 'Volume', {
  availabilityZone: 'us-east-1a',
  size: Size.gibibytes(500),
});


```



### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/aws-cdk-lib/aws-ec2/lib/volume.ts

@@ -3,8 +3,9 @@ import { CfnVolume } from './ec2.generated';
 import { IInstance } from './instance';
 import { AccountRootPrincipal, Grant, IGrantable } from '../../aws-iam';
 import { IKey, ViaServicePrincipal } from '../../aws-kms';
-import { IResource, Resource, Size, SizeRoundingBehavior, Stack, Token, Tags, Names, RemovalPolicy } from '../../core';
+import { IResource, Resource, Size, SizeRoundingBehavior, Stack, Token, Tags, Names, RemovalPolicy, FeatureFlags } from '../../core';
 import { md5hash } from '../../core/lib/helpers-internal';
+import * as cxapi from '../../cx-api';
 
 /**
  * Block device
@@ -65,7 +66,8 @@ export interface EbsDeviceOptionsBase {
    * The EBS volume type
    * @see https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSVolumeTypes.html
    *
-   * @default `EbsDeviceVolumeType.GP2`
+   * @default `EbsDeviceVolumeType.GENERAL_PURPOSE_SSD` or `EbsDeviceVolumeType.GENERAL_PURPOSE_SSD_GP3` if
+   * `@aws-cdk/aws-ec2:ebsDefaultGp3Volume` is enabled.
    */
   readonly volumeType?: EbsDeviceVolumeType;
 }
@@ -621,7 +623,9 @@ export class Volume extends VolumeBase {
       size: props.size?.toGibibytes({ rounding: SizeRoundingBehavior.FAIL }),
       snapshotId: props.snapshotId,
       throughput: props.throughput,
-      volumeType: props.volumeType ?? EbsDeviceVolumeType.GENERAL_PURPOSE_SSD,
+      volumeType: props.volumeType ??
+        (FeatureFlags.of(this).isEnabled(cxapi.EBS_DEFAULT_GP3) ?
+          EbsDeviceVolumeType.GENERAL_PURPOSE_SSD_GP3 : EbsDeviceVolumeType.GENERAL_PURPOSE_SSD),
     });
     resource.applyRemovalPolicy(props.removalPolicy);
 

packages/aws-cdk-lib/aws-ec2/test/volume.test.ts

@@ -2,6 +2,7 @@ import { Match, Template } from '../../assertions';
 import { AccountRootPrincipal, Role } from '../../aws-iam';
 import * as kms from '../../aws-kms';
 import * as cdk from '../../core';
+import * as cxapi from '../../cx-api';
 import {
   AmazonLinuxGeneration,
   EbsDeviceVolumeType,
@@ -457,6 +458,23 @@ describe('volume', () => {
     });
   });
 
+  test('EBS_DEFAULT_GP3 feature flag', () => {
+    // GIVEN
+    const stack = new cdk.Stack();
+
+    // WHEN
+    stack.node.setContext(cxapi.EBS_DEFAULT_GP3, true);
+    new Volume(stack, 'Volume', {
+      availabilityZone: 'us-east-1a',
+      size: cdk.Size.gibibytes(500),
+    });
+
+    // THEN
+    Template.fromStack(stack).hasResourceProperties('AWS::EC2::Volume', {
+      VolumeType: 'gp3',
+    });
+  });
+
   describe('grantAttachVolume to any instance with encryption', () => {
     test('with default key policies', () => {
       // GIVEN

packages/aws-cdk-lib/cx-api/FEATURE_FLAGS.md

@@ -67,7 +67,8 @@ Flags come in three types:
 | [@aws-cdk/aws-codepipeline:crossAccountKeysDefaultValueToFalse](#aws-cdkaws-codepipelinecrossaccountkeysdefaultvaluetofalse) | Enables Pipeline to set the default value for crossAccountKeys to false. | 2.127.0 | (default) |
 | [@aws-cdk/aws-codepipeline:defaultPipelineTypeToV2](#aws-cdkaws-codepipelinedefaultpipelinetypetov2) | Enables Pipeline to set the default pipeline type to V2. | 2.133.0 | (default) |
 | [@aws-cdk/aws-kms:reduceCrossAccountRegionPolicyScope](#aws-cdkaws-kmsreducecrossaccountregionpolicyscope) | When enabled, IAM Policy created from KMS key grant will reduce the resource scope to this key only. | 2.134.0 | (fix) |
-| [@aws-cdk/aws-eks:nodegroupNameAttribute](#aws-cdkaws-eksnodegroupnameattribute) | When enabled, nodegroupName attribute of the provisioned EKS NodeGroup will not have the cluster name prefix. | 2.139.0 | (fix) |
+| [@aws-cdk/aws-eks:nodegroupNameAttribute](#aws-cdkaws-eksnodegroupnameattribute) | When enabled, nodegroupName attribute of the managed EKS NodeGroup will not have the cluster name prefix. | 2.138.0 | (fix) |
+| [@aws-cdk/aws-ec2:ebsDefaultGp3Volume](#aws-cdkaws-ec2ebsdefaultgp3volume) | When enabled, the default volume type of the EBS volume will be GP3 | 2.139.0 | (default) |
 
 <!-- END table -->
 
@@ -126,7 +127,8 @@ The following json shows the current recommended set of flags, as `cdk init` wou
     "@aws-cdk/aws-codepipeline:crossAccountKeysDefaultValueToFalse": true,
     "@aws-cdk/aws-codepipeline:defaultPipelineTypeToV2": true,
     "@aws-cdk/aws-kms:reduceCrossAccountRegionPolicyScope": true,
-    "@aws-cdk/aws-eks:nodegroupNameAttribute": true
+    "@aws-cdk/aws-eks:nodegroupNameAttribute": true,
+    "@aws-cdk/aws-ec2:ebsDefaultGp3Volume": true
   }
 }
 ```
@@ -1280,5 +1282,18 @@ any prefix.
 | (not in v1) |  |  |
 | 2.139.0 | `false` | `true` |
 
+### @aws-cdk/aws-ec2:ebsDefaultGp3Volume
+
+*When enabled, the default volume type of the EBS volume will be GP3* (default)
+
+When this featuer flag is enabled, the default volume type of the EBS volume will be `EbsDeviceVolumeType.GENERAL_PURPOSE_SSD_GP3`.
+
+
+| Since | Default | Recommended |
+| ----- | ----- | ----- |
+| (not in v1) |  |  |
+| 2.139.0 | `false` | `true` |
+
+**Compatibility with old behavior:** Pass `volumeType: EbsDeviceVolumeType.GENERAL_PURPOSE_SSD` to `Volume` construct to restore the previous behavior.
 
 <!-- END details -->

packages/aws-cdk-lib/cx-api/README.md

@@ -326,3 +326,19 @@ _cdk.json_
   }
 }
 ```
+
+* `@aws-cdk/aws-ec2:ebsDefaultGp3Volume`
+
+When enabled, the default volume type of the EBS volume will be GP3.
+
+When this featuer flag is enabled, the default volume type of the EBS volume will be `EbsDeviceVolumeType.GENERAL_PURPOSE_SSD_GP3`
+
+_cdk.json_
+
+```json
+{
+  "context": {
+    "@aws-cdk/aws-ec2:ebsDefaultGp3Volume": true
+  }
+}
+```

packages/aws-cdk-lib/cx-api/lib/features.ts

@@ -102,6 +102,7 @@ export const CODEPIPELINE_CROSS_ACCOUNT_KEYS_DEFAULT_VALUE_TO_FALSE = '@aws-cdk/
 export const CODEPIPELINE_DEFAULT_PIPELINE_TYPE_TO_V2 = '@aws-cdk/aws-codepipeline:defaultPipelineTypeToV2';
 export const KMS_REDUCE_CROSS_ACCOUNT_REGION_POLICY_SCOPE = '@aws-cdk/aws-kms:reduceCrossAccountRegionPolicyScope';
 export const EKS_NODEGROUP_NAME = '@aws-cdk/aws-eks:nodegroupNameAttribute';
+export const EBS_DEFAULT_GP3 = '@aws-cdk/aws-ec2:ebsDefaultGp3Volume';
 
 export const FLAGS: Record<string, FlagInfo> = {
   //////////////////////////////////////////////////////////////////////
@@ -1047,6 +1048,18 @@ export const FLAGS: Record<string, FlagInfo> = {
     introducedIn: { v2: '2.139.0' },
     recommendedValue: true,
   },
+
+  //////////////////////////////////////////////////////////////////////
+  [EBS_DEFAULT_GP3]: {
+    type: FlagType.ApiDefault,
+    summary: 'When enabled, the default volume type of the EBS volume will be GP3',
+    detailsMd: `
+      When this featuer flag is enabled, the default volume type of the EBS volume will be \`EbsDeviceVolumeType.GENERAL_PURPOSE_SSD_GP3\`.
+    `,
+    introducedIn: { v2: 'V2NEXT' },
+    recommendedValue: true,
+    compatibilityWithOldBehaviorMd: 'Pass `volumeType: EbsDeviceVolumeType.GENERAL_PURPOSE_SSD` to `Volume` construct to restore the previous behavior.',
+  },
 };
 
 const CURRENT_MV = 'v2';