cdk-spot-one

One spot instance with EIP and defined duration. No interruption.

Why

Sometimes we need an Amazon EC2 instance with static fixed IP for testing or development purpose for a duration of time(probably hours). We need to make sure during this time, no interruption will occur and we don't want to pay for on-demand rate. cdk-spot-one helps you reserve one single spot instance with pre-allocated or new Elastic IP addresses(EIP) with defined blockDuration, during which time the spot instance will be secured with no spot interruption.

Behind the scene, cdk-spot-one provisions a spot fleet with capacity of single instance for you and it associates the EIP with this instance. The spot fleet is reserved as spot block with blockDuration from one hour up to six hours to ensure the high availability for your spot instance.

Multiple spot instances are possible by simply specifying the targetCapacity construct property, but we only associate the EIP with the first spot instance at this moment.

Enjoy your highly durable one spot instance with AWS CDK!

Sample

import { SpotFleet } from 'cdk-spot-one';

// create the first fleet for one hour and associate with our existing EIP
const fleet = new SpotFleet(stack, 'SpotFleet')

// configure the expiration after 1 hour
fleet.expireAfter(Duration.hours(1))


// create the 2nd fleet with single Gravition 2 instance for 6 hours and associate with new EIP
const fleet2 = new SpotFleet(stack, 'SpotFleet2', {
  blockDuration: BlockDuration.SIX_HOURS,
  eipAllocationId: 'eipalloc-0d1bc6d85895a5410',
  defaultInstanceType: new InstanceType('c6g.large'),
  vpc: fleet.vpc,
})
// configure the expiration after 6 hours
fleet2.expireAfter(Duration.hours(6))

// print the instanceId from each spot fleet
new CfnOutput(stack, 'SpotFleetInstanceId', { value: fleet.instanceId })
new CfnOutput(stack, 'SpotFleet2InstanceId', { value: fleet2.instanceId })

ARM64 and Graviton 2 support

cdk-spot-one selects the latest Amazon Linux 2 AMI for your ARM64 instances. Simply select the instance types with the defaultInstanceType property and the SpotFleet will auto configure correct AMI for the instance.

defaultInstanceType: new InstanceType('c6g.large')

SSH connect

By default the cdk-spot-one does not assign any SSH public key for you on the instance. You are encouraged to use ec2-instance-connect to send your public key from local followed by one-time SSH connect.

For example:

pubkey="$HOME/.ssh/aws_2020_id_rsa.pub"
echo "sending public key to ${instanceId}"
aws ec2-instance-connect send-ssh-public-key --instance-id ${instanceId} --instance-os-user ec2-user \
--ssh-public-key file://${pubkey} --availability-zone ${az} 

You may also create a simple ec2-connect.sh script like this and save in your $PATH:

#!/bin/bash

instanceId=$1
pubkey="$HOME/.ssh/aws_2020_id_rsa.pub"
sshUser='ec2-user'

az=$(aws ec2 describe-instances --instance-id ${instanceId} --query 'Reservations[0].Instances[0].Placement.AvailabilityZone' --output text)
publicIp=$(aws ec2 describe-instances --instance-id ${instanceId} --query 'Reservations[0].Instances[0].PublicIpAddress' --output text)


echo "sending public key to ${instanceId}"
aws ec2-instance-connect send-ssh-public-key --instance-id ${instanceId} --instance-os-user ${sshUser} \
--ssh-public-key file://${pubkey} --availability-zone ${az} > /dev/null

if [[ $2 != '--send-key-only' ]]; then
  echo "connecting to ${publicIp} at ${az}"
	ssh ${sshUser}@${publicIp}
fi

And simply run this to connect to the EC2 instance.

$ ec2-connect.sh i-01f827ab9de7b93a9

It's also possible to explicitly specify your existing SSH key with the keyName construct property if you like.