* add support for using ansible 2.10.x for deploying kubespray
* move dns-autoscaler-clusterrole{binding}.yml to files/ folder
* note that ansible 2.10 is now experimentally supported
* coredns: move files to templates like before #4341
* add initial MetalLB docs
* metallb allow disabling the deployment of the metallb speaker
* calico>=3.18 allow using calico to advertise service loadbalancer IPs
* Document the use of MetalLB and Calico
* clean MetalLB docs
Since K8S 1.21, BoundServiceAccountTokenVolume feature gate is in beta stage, thus activated by default (anyone who follows CSI guidelines has enabled AllAlpha and faced the issue before 1.21).
With this feature, SA tokens are regenerated every hour.
As a consequence for Calico CNI, token in /etc/cni/net.d/calico-kubeconfig copied from /var/run/secrets/kubernetes.io/serviceaccount in install-cni initContainer expires after one hour and any pod creation fails due to unauthorization.
Calico pods need to be restarted so that /etc/cni/net.d/calico-kubeconfig is updated with the new SA token.
follow new naming conventions for gcr's coredns image.
starting from 1.21 kubeadm assumes it to be `coredns/coredns`:
this causes the kubeadm deployment being unable to pull image, beacuse `v`
was also added in image tag, until the role `kubernetes-apps` ovverides
it with the old name, which is only compatible with <=1.7.
Backward comptability with kubeadm <=1.20 is mantained checking
kubernetes version and falling back to old names (`coredns:1.xx`) when
the version is less than 1.21
* rename ansible groups to use _ instead of -
k8s-cluster -> k8s_cluster
k8s-node -> k8s_node
calico-rr -> calico_rr
no-floating -> no_floating
Note: kube-node,k8s-cluster groups in upgrade CI
need clean-up after v2.16 is tagged
* ensure old groups are mapped to the new ones
* crio: add supported versions 1.20 and 1.21 and align default with k8s version
* cri-o: drop versions 1.17 and 1.18 from version matrix
* update note on cri-o version alignment
* calico: drop support for version 3.15
* drop check for calico version >= 3.3, we are at 3.16 minimum now
* we moved to calico 3.16+ so we can default to /opt/cni/bin/install
* AlmaLinux: ansible>2.9.19 is needed to know about AlmaLinux
* AlmaLinux: identify as a centos derrivative
* AlmaLinux: add AlmaLinux to checks for CentOS
* Use ansible_os_family to compare family and not distribution
