The previous strategy for provisioning infrastructure targets was to use
the cheapest instances that could reliably perform as Vault cluster
nodes. With this change we introduce a new model for target node
infrastructure. We've replaced on-demand instances for a spot
fleet. While the spot price fluctuates based on dynamic pricing,
capacity, region, instance type, and platform, cost savings for our
most common combinations range between 20-70%.
This change only includes spot fleet targets for Vault clusters.
We'll be updating our Consul backend bidding in another PR.
* Create a new `vault_cluster` module that handles installation,
configuration, initializing, and unsealing Vault clusters.
* Create a `target_ec2_instances` module that can provision a group of
instances on-demand.
* Create a `target_ec2_spot_fleet` module that can bid on a fleet of
spot instances.
* Extend every Enos scenario to utilize the spot fleet target acquisition
strategy and the `vault_cluster` module.
* Update our Enos CI modules to handle both the `aws-nuke` permissions
and also the privileges to provision spot fleets.
* Only use us-east-1 and us-west-2 in our scenario matrices as costs are
lower than us-west-1.
Signed-off-by: Ryan Cragun <me@ryan.ec>
This uses aws-nuke and awslimitchecker to monitor the new vault CI account to clean up and prevent resource quota exhaustion. AWS-nuke will scan all regions of the accounts for lingering resources enos/terraform didn't clean up, and if they don't match exclusion criteria, delete them every night. By default, we exclude corp-sec created resources, our own CI resources, and when possible, anything created within the past 72 hours. Because this account is dedicated to CI, users should not expect resources to persist beyond this without additional configuration.
