* Replace v0.11 bracket type hints with Terraform v0.12 list expressions
* Use expression syntax instead of interpolated strings, where suggested
* Update DigitalOcean tutorial documentation
* Define Terraform and plugin version requirements in versions.tf
* Require digitalocean ~> v1.3 to support Terraform v0.12
* Require ct ~> v0.3.2 to support Terraform v0.12
* Introduce "calico" as a `networking` option on Azure and DigitalOcean
using Calico's new VXLAN support (similar to flannel). Flannel remains
the default on these platforms for now.
* Historically, DigitalOcean and Azure only allowed Flannel as the
CNI provider, since those platforms don't support IPIP traffic that
was previously required for Calico.
* Looking forward, its desireable for Calico to become the default
across Typhoon clusters, since it provides NetworkPolicy and a
consistent experience
* No changes to AWS, GCP, or bare-metal where Calico remains the
default CNI provider. On these platforms, IPIP mode will always
be used, since its available and more performant than vxlan
* Add an `enable_aggregation` variable to enable the kube-apiserver
aggregation layer for adding extension apiservers to clusters
* Aggregation is **disabled** by default. Typhoon recommends you not
enable aggregation. Consider whether less invasive ways to achieve your
goals are possible and whether those goals are well-founded
* Enabling aggregation and extension apiservers increases the attack
surface of a cluster and makes extensions a part of the control plane.
Admins must scrutinize and trust any extension apiserver used.
* Passing a v1.14 CNCF conformance test requires aggregation be enabled.
Having an option for aggregation keeps compliance, but retains the
stricter security posture on default clusters
* Calico Felix has been reporting anonymous usage data about the
version and cluster size, which violates Typhoon's privacy policy
where analytics should be opt-in only
* Add a variable enable_reporting (default: false) to allow opting
in to reporting usage data to Calico (or future components)
* Calico isn't viable on Digital Ocean because their firewalls
do not support IP-IP protocol. Its not viable to run a cluster
without firewalls just to use Calico.
* Remove the caveat note. Don't allow users to shoot themselves
in the foot
* Introduce the ability to support Container Linux Config
"snippets" for controllers and workers on cloud platforms.
This allows end-users to customize hosts by providing Container
Linux configs that are additively merged into the base configs
defined by Typhoon. Config snippets are validated, merged, and
show any errors during `terraform plan`
* Example uses include adding systemd units, network configs,
mounts, files, raid arrays, or other disk provisioning features
provided by Container Linux Configs (using Ignition low-level)
* Requires terraform-provider-ct v0.2.1 plugin
* Allow kube-dns to respond to DNS queries with a custom
suffix, instead of the default 'cluster.local'
* Useful when multiple clusters exist on the same local
network and wish to query services on one another
* Calico on GCE with IP-in-IP encapsulation and MTU 1440
* Calico on DO with IP-in-IP encapsulation and MTU 1440
* Digital Ocean firewalls don't support IPIP protocol yet
* Remove k8s_domain_name input variable, the controller DNS
record will be "${var.cluster_name}.${dns_zone}"
* Rename dns_base_zone to dns_zone
* Rename dns_base_zone_name to dns_zone_name