Begin the process of migrating away from the "strongly encouraged not to
use"[0] Ec2 spot fleet API to the more modern `ec2:CreateFleet`.
Unfortuantely the `instant` type fleet does not guarantee fulfillment
with either on-demand or spot types. We'll need to add a feature similar
to `wait_for_fulfillment` on the `spot_fleet_request` resource[1] to
`ec2_fleet` before we can rely on it.
We also update the existing target fleets to support provisioning generic
targets. This has allowed us to remove our usage of `terraform-enos-aws-consul`
and replace it with a smaller `backend_consul` module in-repo.
We also remove `terraform-enos-aws-infra` and replace it with two smaller
in-repo modules `ec2_info` and `create_vpc`. This has allowed us to simplify
the vpc resources we use for each scneario, which in turn allows us to
not rely on flaky resources.
As part of this refactor we've also made it possible to provision
targets using different distro versions.
[0] https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/spot-best-practices.html#which-spot-request-method-to-use
[1] https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/spot_fleet_request#wait_for_fulfillment
* enos/consul: add `backend_consul` module that accepts target hosts.
* enos/target_ec2_spot_fleet: add support for consul networking.
* enos/target_ec2_spot_fleet: add support for customizing cluster tag
key.
* enos/scenarios: create `target_ec2_fleet` which uses a more modern
`ec2_fleet` API.
* enos/create_vpc: replace `terraform-enos-aws-infra` with smaller and
simplified version. Flatten the networking to a single route on the
default route table and a single subnet.
* enos/ec2_info: add a new module to give us useful ec2 information
including AMI id's for various arch/distro/version combinations.
* enos/ci: update service user role to allow for managing ec2 fleets.
Signed-off-by: Ryan Cragun <me@ryan.ec>
