Create/associate ssh keypair to an ec2 instance with the CDK

Question

I'm using the new Cloud Development Toolkit (CDK) to build an infrastructure on AWS using Java language.

I'm using a Bastion Host on a public subnet to communicate with an RDS instance on a private subnet, so I reach the database (on the private subnet) externally via an ssh tunnelling on the Bastion Host.

I've created the BastionHost in this way:

BastionHostLinux
            .Builder
            .create(scope, bastionId)
            .vpc(vpc)
            .instanceType(InstanceType.of(InstanceClass.BURSTABLE2, InstanceSize.SMALL))
            .subnetSelection(subnetSelection)
            .instanceName(bastionName)
            .build();

I don't find any method to create or associate ssh key pair to the instance, so when I try to connect, aws tell me that I don't have any ssh key pair associated with the ec2 instance.

My question is: How can I associate an already existent keypair with an ec2 instance using the CDK? Or, (it would be better) how can I create a fresh key pair using the CDK?

Answer 1

You can use addPropertyOverride to set an existing key for the bastion host.

    const bastionSecurityGroup = new ec2.SecurityGroup(this, 'BastionSecurityGroup', {
      vpc,
    });
    const bastion = new ec2.BastionHostLinux(this, 'Bastion', {
      vpc,
      subnetSelection: { subnetType: ec2.SubnetType.PUBLIC },
      instanceName: `my-bastion`,
    });
    bastion.instance.instance.addPropertyOverride('KeyName', `my-bastion-key`);