==================== OFFLINE KUBERNETES INSTALL (RHEL 8.10) ====================

CLUSTER DETAILS
---------------
MASTER  : 192.168.241.160
WORKERS : 192.168.241.161 , 192.168.241.162
K8S     : v1.30.14
RUNTIME : containerd
CNI     : flannel
ARTIFACTS PATH : /data
packages in /data: conntrack-tools-1.4.4-11.el8.x86_64, containerd.io-1.6.32-3.1.el8.x86_64, cri-tools-1.30.1-150500.1.1.x86_64, ethtool-5.13-2.el8.x86_64, iproute-6.2.0-6.el8_10.x86_64, iproute-tc-6.2.0-6.el8_10.x86_64, iptables-1.8.5-11.el8_9.x86_64, iptables-ebtables-1.8.5-11.el8_9.x86_64, kubeadm-1.30.14-150500.1.1.x86_64, kubectl-1.30.14-150500.1.1.x86_64, kubelet-1.30.14-150500.1.1.x86_64, kubernetes-cni-1.4.0-150500.1.1.x86_64, socat-1.7.4.1-2.el8_10.x86_64, createrepo, bash-auoconnect

================================================================================
STEP 0 : COMMON SETUP (RUN ON ALL NODES)
================================================================================

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

cat <<EOF >/etc/modules-load.d/k8s.conf
overlay
br_netfilter
EOF

modprobe overlay
modprobe br_netfilter

cat <<EOF >/etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-ip6tables=1
net.ipv4.ip_forward=1
EOF

sysctl --system

================================================================================
STEP 1 : CONFIGURE OFFLINE REPO (RUN ON ALL NODES)
================================================================================

cat <<EOF >/etc/yum.repos.d/k8s-offline.repo
[k8s-offline]
name=Kubernetes Offline Repo
baseurl=file:///data/k8s-rpms
enabled=1
gpgcheck=0
EOF

dnf clean all

================================================================================
STEP 2 : INSTALL PACKAGES (RUN ON ALL NODES)
================================================================================

dnf install -y \
containerd.io \
kubeadm kubelet kubectl cri-tools kubernetes-cni \
conntrack-tools iproute iproute-tc iptables iptables-ebtables ethtool socat

systemctl enable --now containerd
systemctl enable kubelet

================================================================================
STEP 3 : CONFIGURE CONTAINERD (RUN ON ALL NODES)
================================================================================

containerd config default > /etc/containerd/config.toml

sed -i 's/SystemdCgroup = false/SystemdCgroup = true/' \
/etc/containerd/config.toml

systemctl restart containerd
systemctl status containerd

================================================================================
STEP 4 : IMPORT IMAGES (OFFLINE)
================================================================================

# MASTER ONLY
ctr -n k8s.io images import /data/offline/k8s-images.tar
ctr -n k8s.io images import /data/offline/flannel.tar

# WORKERS ONLY
ctr -n k8s.io images import /data/offline/k8s-images.tar

================================================================================
STEP 5 : INITIALIZE CLUSTER (MASTER ONLY)
================================================================================

kubeadm init \
--apiserver-advertise-address=192.168.241.160 \
--pod-network-cidr=10.244.0.0/16

================================================================================
STEP 6 : CONFIGURE kubectl (MASTER ONLY)
================================================================================

mkdir -p $HOME/.kube
cp /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config

================================================================================
STEP 7 : INSTALL FLANNEL (MASTER ONLY, OFFLINE)
================================================================================

export KUBECONFIG=/etc/kubernetes/admin.conf
kubectl apply -f /data/offline/kube-flannel.yml

kubectl get pods -n kube-system

================================================================================
STEP 8 : JOIN WORKER NODES
================================================================================

# ON MASTER
kubeadm token create --print-join-command

# RUN OUTPUT COMMAND ON EACH WORKER
kubeadm reset -f

rm -rf /etc/cni/net.d
rm -rf /var/lib/cni
rm -rf /var/lib/kubelet/*

systemctl restart containerd
systemctl restart kubelet

kubeadm join 192.168.241.160:6443 \
--token <TOKEN> \
--discovery-token-ca-cert-hash sha256:<HASH>

================================================================================
STEP 9 : VERIFY CLUSTER (MASTER ONLY)
================================================================================

kubectl get nodes -o wide

EXPECTED OUTPUT
---------------
control   Ready   control-plane
node1     Ready
node2     Ready

==================== OFFLINE KUBERNETES INSTALL COMPLETE =======================