* Replace os_channel variable with os_image to align naming
across clouds. Users who set this option to stable, beta, or
alpha should now set os_image to coreos-stable, coreos-beta,
or coreos-alpha.
* Default os_image to coreos-stable. This continues to use
the most recent image from the stable channel as always.
* Allow Container Linux derivative Flatcar Linux by setting
os_image to `flatcar-stable`, `flatcar-beta`, `flatcar-alpha`
* Add `worker_price` to allow worker spot instances. Defaults
to empty string for the worker autoscaling group to use regular
on-demand instances.
* Add `spot_price` to internal `workers` module for spot worker
pools
* Note: Unlike GCP `preemptible` workers, spot instances require
you to pick a bid price.
* Fix issue where worker firewall rules didn't apply to
additional workers attached to a GCP cluster using the new
"worker pools" feature (unreleased, #148). Solves host
connection timeouts and pods not being scheduled to attached
worker pools.
* Add `name` field to GCP internal worker module to represent
the unique name of of the worker pool
* Use `cluster_name` field of GCP internal worker module for
passing the name of the cluster to which workers should be
attached
* This reverts commit cce4537487.
* Provider passing to child modules is complex and the behavior
changed between Terraform v0.10 and v0.11. We're continuing to
allow both versions so this change should be reverted. For the
time being, those using our internal Terraform modules will have
to be aware of the minimum version for AWS and GCP providers,
there is no good way to do enforcement.
* Allow groups of workers to be defined and joined to
a cluster (i.e. worker pools)
* Move worker resources into a Terraform submodule
* Output variables needed for passing to worker pools
* Add usage docs for AWS worker pools (advanced)
* Set defaults for internal worker module's count,
machine_type, and os_image
* Allow "pools" of homogeneous workers to be created
using the google-cloud/kubernetes/workers module
