* Update vars.md to remove mention of string syntax of node_labels

Fixes https://github.com/kubernetes-sigs/kubespray/issues/6215

* Try fix makrdown linting

* Update docs/vars.md

* Update nodes.md

* fix syntax

* fix syntax - part 2

* replace master with kube_control_plane

* return etcd-master

https://github.com/kubernetes-incubator/kubespray is an old link,
this updates the link.

* replaced deprecated python package with python3 package

* removed the version due to duplication

When reset, need to clean up directory /usr/libexec.

This replaces master with "control plane" in Kubespray docs
because of [1].

[1]: https://github.com/kubernetes/enhancements/blob/master/keps/sig-cluster-lifecycle/kubeadm/2067-rename-master-label-taint/README.md#motivation

Although these errors are not important, they affect the code specification.

* Claico Docs: clarify the algorithm to calculate calico_veth_mtu

* Update sample calico_veth_mtu

* Enable Graceful Node Shutdown for Kubernetes >= 1.21.0

* Add sample graceful shutdown parameters

* Calico: add Wireguard support

* CI: Add Calico Wireguard scenario

I recently reviewed the code, although these errors are not important, they affect the code specification.

* fix broken link in doc

* Revert "fix broken link in doc"

This reverts commit b427d1f57ff35375a97444f79eb06caf608c75d7.

* move metallb doc to right place, fixing broken link

When reset, need to clean up files kube_proxy-ipvs.conf and kubespray-br_netfilter.conf.

* terraform/openstack: Use path.root for ansible_bastion_template.txt

The path.root variable points to the root module path. Using this
instead of a relative path makes less assumptions about the current
working directory.

* terraform/openstack: Add group_vars_path variable

Previously, the group_vars path was assumed to be in CWD. The
default value for the group_vars_path variable is still relative
to CWD and thus should be backwards compatible if unset.

It's a minor change, I just corrected `–` char to `-`.

* fix group name

* fix external-openstack-cloud-config secret

* don't add ca.cert in the secret if not defined

* Clean up residual files

When reset, you need to clean up to the kerw directory.

* Update main.yml

* Docker/Containerd: move downloads urls to containerd-common

* gVisor: initial support for gVisor container runtime

$releasever can be 7Server, but there is no such CentOS path on
download.opensuse.org.

Use ansible_distribution_major_version instead of $releasever.

As [1], v2.4.0 has been released already for local_volume_provisioner.
This updates the version.

[1]: https://github.com/kubernetes-sigs/sig-storage-local-static-provisioner/tags

We have released v2.16 of Kubespray already, so we can remove those
old groups from the test inventory as the TODO says.

* Improve scale flow

* Add confirmation prompt again

* Calico: align manifests with upstream

* allow enabling typha prometheus metrics

* Calico: enable eBPF support

* manage the kubernetes-services-endpoint configmap

* Calico: document the use of eBPF dataplane

* Calico: improve checks before deployment

* enforce disabling kube-proxy when using eBPF dataplane
* ensure calico_version is supported

* Kata: add Kata 2.x checksums and adjust download urls for 2.x

* Kata: drop 1.x version which is no longer supported

* Kata: set default version 2.1.0