title: How to attach an EC2 volume to an EC2 instance using AWS CDK
body: <p>I'd like to attach an EC2 volume to an EC2 instance I'm creating, but can't figure out how to do it:</p>
  <pre><code>const vol = new ec2.Volume(this, 'vol', {
    availabilityZone: 'ap-southeast-2a',
    size: Size.gibibytes(100),
  });
  
  const instance = new ec2.Instance(this, 'my-instance', {
    instanceName: 'my-instance',
    vpc: vpc,
    // how to attach 'vol' as a block device here?
    blockDevices: [{ deviceName: '/dev/sdf', volume: { ebsDevice: { deleteOnTermination: false, volumeSize: 1 } } }],
    //... more props
  });
  </code></pre>
  <p>This code works, though <code>vol</code> is not attached as a block device. How can I achieve this?</p>