Remove deprecated nodeSelector label beta.kubernetes.io/os

[brandond]

From @evilhamsterman

The nodeSelector label beta.kubernetes.io/os in the CoreDNS deployment was deprecated in 1.14 and will likely be removed soon

[VestigeJ]

##Environment Details

Reproduced using VERSION=v1.26.2+k3s1
Validated using VERSION=v1.26.3-rc1+k3s1

Infrastructure

• Cloud

Node(s) CPU architecture, OS, and version:

Linux 5.14.0-162.6.1.el9_1.x86_64 x86_64 GNU/Linux 
PRETTY_NAME="Rocky Linux 9.1 (Blue Onyx)"

Cluster Configuration:

NAME                                          STATUS   ROLES                  AGE   VERSION
ip-CHOMOLUNGMA-NODE                            Ready    control-plane,master   11m   v1.26.2+k3s1 

Config.yaml:

N/A

Confirmed beta label on previous release

$ curl https://get.k3s.io --output install-"k3s".sh
$ sudo chmod +x install-"k3s".sh
$ sudo groupadd --system etcd && sudo useradd -s /sbin/nologin --system -g etcd etcd
$ sudo modprobe ip_vs_rr
$ sudo modprobe ip_vs_wrr
$ sudo modprobe ip_vs_sh
$ sudo printf "on_oovm.panic_on_oom=0 \nvm.overcommit_memory=1 \nkernel.panic=10 \nkernel.panic_ps=1 \nkernel.panic_on_oops=1 \n" > ~/60-rke2-cis.conf
$ sudo cp 60-rke2-cis.conf /etc/sysctl.d/
$ sudo systemctl restart systemd-sysctl
$ sudo INSTALL_K3S_VERSION=v1.26.2+k3s1 INSTALL_K3S_EXEC=server ./install-k3s.sh 
$ set_kubefig //export KUBECONFIG=/etc/rancher/k3s/k3s.yaml
$ kgp -A //kubectl get pods -A find the coredns pod name
$ kd pod/coredns-5c6b6c5476-rdt9k -n kube-system | grep -i beta //kubectl describe
$ kgn //kubectl get nodes
$ get_report // generate this template

Results:

$ kd pod/coredns-5c6b6c5476-rdt9k -n kube-system | grep -i "node-selectors"

Node-Selectors:               beta.kubernetes.io/os=linux

Validated node-selector does not have beta label anymore

Validation Steps

$ curl https://get.k3s.io --output install-"k3s".sh
$ sudo chmod +x install-"k3s".sh
$ sudo groupadd --system etcd && sudo useradd -s /sbin/nologin --system -g etcd etcd
$ sudo modprobe ip_vs_rr
$ sudo modprobe ip_vs_wrr
$ sudo modprobe ip_vs_sh
$ sudo printf "on_oovm.panic_on_oom=0 \nvm.overcommit_memory=1 \nkernel.panic=10 \nkernel.panic_ps=1 \nkernel.panic_on_oops=1 \n" > ~/60-rke2-cis.conf
$ sudo cp 60-rke2-cis.conf /etc/sysctl.d/
$ sudo systemctl restart systemd-sysctl
$ sudo INSTALL_K3S_VERSION=v1.26.3-rc1+k3s1 INSTALL_K3S_EXEC=server ./install-k3s.sh 
$ set_kubefig //export KUBECONFIG=/etc/rancher/k3s/k3s.yaml
$ kgp -A //kubectl get pods -A find the coredns pod name
$ kd pod/coredns-7c444649cb-xznhl -n kube-system | grep -i beta //kubectl describe
$ kgn //kubectl get nodes
$ get_report // generate this template

Results:

$ kd pod/coredns-7c444649cb-xznhl -n kube-system | grep -i "node-selectors"

Node-Selectors:               kubernetes.io/os=linux