* When using the Cilium component, disable bootstrapping the
kube-proxy DaemonSet. Instead, configure Cilium to provide its
kube-proxy replacement with BPF
* Update the self-managed Cilium component to use kube-proxy
replacement as well
* Use EC2 resource-based hostnames instead of IP-based hostnames. The Amazon
DNS server can resolve A and AAAA queries to IPv4 and IPv6 node addresses
* For example, nodes used to be named like `ip-10-11-12-13.us-east-1.compute.internal`
but going forward use the instance id `i-0123456789abcdef.us-east-1.compute.internal`
* Tag controller node EBS volumes with a name based on the controller node name
* Drop support for `cluster_domain_suffix` customization and
always use `cluster.local`. Many components in the Kubernetes
ecosystem assume this default suffix and its very rare to be
setting a special value here these days
* Cleanup a few variables that are seldom used
* Add `controller_disk_type`, `controller_disk_size`, and `controller_disk_iops`
variables
* Add `worker_disk_type`, `worker_disk_size`, and `worker_disk_iops` variables
and fix propagation to worker nodes
* Remove `disk_type`, `disk_size`, and `disk_iops` variables
* Add `controller_cpu_credits` and `worker_cpu_credits` variables to set CPU
pricing mode for burstable instance types
* AWS has recently started defaulting launch templates to IMDSv2
being "required". aws_launch_template is supposed to default to
"optional" but it doesn't.
* Requiring IMDSv2 sessions breaks a number of applications which
don't use AWS SDKs and were never meant to be complex applications
(e.g. shell scripts and the like)
* Changes to worker launch configurations start an autoscaling group instance
refresh to replace instances
* Instance refresh creates surge instances, waits for a warm-up period, then
deletes old instances
* Changing worker_type, disk_*, worker_price, worker_target_groups, or Butane
worker_snippets on existing worker nodes will replace instances
* New AMIs or changing `os_stream` will be ignored, to allow Fedora CoreOS or
Flatcar Linux to keep themselves updated
* Previously, new launch configurations were made in the same way, but not
applied to instances unless manually replaced
* Rename launch configuration to use a name_prefix named after the
cluster and worker to improve identifiability
* Shorten AWS autoscaling group name to not include the launch config
id. Years ago this used to be needed to update the ASG but the AWS
provider detects changes to the launch configuration just fine
* Requires poseidon v0.11+ and Flatcar Linux 3185.0.0+ (action required)
* Previously, Flatcar Linux configs have been parsed as Container
Linux Configs to Ignition v2.2.0 specs by poseidon/ct
* Flatcar Linux starting in 3185.0.0 now supports Ignition v3.x specs
(which are rendered from Butane Configs, like Fedora CoreOS)
* poseidon/ct v0.11.0 adds support for the flatcar Butane Config
variant so that Flatcar Linux can use Ignition v3.x
Rel:
* [Flatcar Support](https://flatcar-linux.org/docs/latest/provisioning/ignition/specification/#ignition-v3)
* [poseidon/ct support](https://github.com/poseidon/terraform-provider-ct/pull/131)
* Add `node_taints` variable to worker modules to set custom
initial node taints on cloud platforms that support auto-scaling
worker pools of heterogeneous nodes (i.e. AWS, Azure, GCP)
* Worker pools could use custom `node_labels` to allowed workloads
to select among differentiated nodes, while custom `node_taints`
allows a worker pool's nodes to be tainted as special to prevent
scheduling, except by workloads that explicitly tolerate the
taint
* Expose `daemonset_tolerations` in AWS, Azure, and GCP kubernetes
cluster modules, to determine whether `kube-system` components
should tolerate the custom taint (advanced use covered in docs)
Rel: #550, #663Closes#429
* Flatcar Linux has not published an Edge channel image since
April 2020 and recently removed mention of the channel from
their documentation https://github.com/kinvolk/Flatcar/pull/345
* Users of Flatcar Linux Edge should move to the stable, beta, or
alpha channel, barring any alternate advice from upstream Flatcar
Linux
* CoreOS Container Linux was deprecated in v1.18.3
* Continue transitioning docs and modules from supporting
both CoreOS and Flatcar "variants" of Container Linux to
now supporting Flatcar Linux and equivalents
Action Required: Update the Flatcar Linux modules `source`
to replace `s/container-linux/flatcar-linux`. See docs for
examples
