Install K3S on CentOS8

1 VM Setup

1.1 VM requirements

Just setup a CentOS8 minimal VM with the following requirements

• OS: centos8 minimal

• CPU: 2
• MEM: 8GB (6 GB may work as well)
• DISK: 40G (7GB used on a fresh setup)

1.2 Prepare OS

dnf -y upgrade
dnf -y install setroubleshoot-server curl lsof wget tar

sed -i  '/swap/d' /etc/fstab
swapoff -a

firewall-cmd --permanent --zone=public --add-service=https
firewall-cmd --zone=public --add-masquerade --permanent
firewall-cmd --reload
reboot

2 Setup K3S

curl -sfL https://get.k3s.io | sh

cat /etc/systemd/system/k3s.service
systemctl status k3s

kubectl get nodes
# all pods in running state? fine!
kubectl get pods --all-namespaces

3 DNS for Wildcard Ingress

• Create a CNAME

*.vm-name.domain.tld -> vm-name.domain.tld

4 Helm Install

curl https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | sh
grep 'helm completion bash' $HOME/.bashrc || echo 'source <(helm completion bash)' >> $HOME/.bashrc

grep KUBECONFIG $HOME/.bashrc || echo 'export KUBECONFIG=/etc/rancher/k3s/k3s.yaml' >> $HOME/.bashrc

4.1 .bash_profile

• kubectl project/user prompt

source <(kubectl completion bash)
export PS1='### \D{%d.%m.%Y_%H:%M} \u@\e[1;32m\h\e[m:\w \e[1;33m✯ $(kubectl config view -o jsonpath="{.contexts[].context.namespace}")\e[m \n# '

• password gen

genpasswd() {
   local l=$1
   [ "$l" == "" ] && l=16
   tr -dc A-Za-z0-9_=., < /dev/urandom | head -c ${l} | xargs 
}