aws_ec2: passing keyPair to Instance does nothing

[SamuraiPrinciple]

Describe the bug

With keyName property being deprecated (#28138), creating aws_ec2.KeyPair and passing it to aws_ec2.Instance does nothing.

Expected Behavior

Make sure the keypair is associated with the instance when passed through keyPair property.

Current Behavior

keypair does not get associated with the instance.

Reproduction Steps

const keyPair = new ec2.KeyPair(this, 'KeyPair', {});
 this.instance = new ec2.Instance(this, 'EC2Instance', {
      vpc: props.vpc,
      vpcSubnets: { subnetType: ec2.SubnetType.PUBLIC },
      securityGroup,
      instanceType: ec2.InstanceType.of(ec2.InstanceClass.T3, ec2.InstanceSize.MICRO),
      machineImage: ec2.MachineImage.latestAmazonLinux2023(),
      keyPair,
      userDataCausesReplacement: true,
      ssmSessionPermissions: true,
    });

Possible Solution

No response

Additional Information/Context

No response

CDK CLI Version

2.116.1 (build 222de71)

Framework Version

No response

Node.js Version

20.10.0

OS

Linux

Language

TypeScript

Language Version

No response

Other information

No response

[tam0ri]

props.keyPair is never referred as property of CfnInstance.

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

Lines 438 to 453 in 8071015

	this.instance = new CfnInstance(this, 'Resource', {
	imageId: imageConfig.imageId,
	keyName: props.keyName,
	instanceType: props.instanceType.toString(),
	subnetId: networkInterfaces ? undefined : subnet.subnetId,
	securityGroupIds: networkInterfaces ? undefined : securityGroupsToken,
	networkInterfaces,
	iamInstanceProfile: iamProfile.ref,
	userData: userDataToken,
	availabilityZone: subnet.availabilityZone,
	sourceDestCheck: props.sourceDestCheck,
	blockDeviceMappings: props.blockDevices !== undefined ? instanceBlockDeviceMappings(this, props.blockDevices) : undefined,
	privateIpAddress: networkInterfaces ? undefined : props.privateIpAddress,
	propagateTagsToVolumeOnCreation: props.propagateTagsToVolumeOnCreation,
	monitoring: props.detailedMonitoring,
	});

Specifying props.keyPair?.keyPairName for keyName property as same as LaunchTemplate will solve the issue.

aws-cdk/packages/aws-cdk-lib/aws-ec2/lib/launch-template.ts

Line 758 in 8071015

keyName: props.keyPair?.keyPairName ?? props?.keyName,

It seems to be easy to fix and suitable for good first issue. I can take this, but if anyone is interested in submitting PR, please feel free to try it :)

[pahud]

Awesome! Thank you for the PR!

[fire015]

+1 having the same problem

[yuki549]

+1 having the same problem

[GuillaumeEscande]

+1 having the same problem

[mrgrain]

Please use the 👍🏻 reaction on the original post if you have the same issue. Plus there already is a PR with potential fix open: #28482