Worker Node Installation

Repeat the steps from Step 1 to Step 4. Then execute the following:

1. Use the token generated from the Master Node:

     Eg:  kubeadm join :6443 --token --discovery-token-ca-cert-hash sha256: 

2. Fix the flannel on worker node:

   cat <<'EOF' | sudo tee /usr/local/bin/flannel-dns-fix.sh
   #!/bin/bash
   if [ ! -d /sys/class/net/flannel.1 ]; then
   logger "flannel-dns-fix: flannel.1 not found, will retry later"
   exit 1
   fi
   /usr/sbin/ethtool -K flannel.1 tx off 2>/dev/null || true
   logger "flannel-dns-fix: Disabled TX checksum offload on flannel.1"
   PHYS_INT=$(ip route | grep default | awk '{print $5}')
   if [ -n "$PHYS_INT" ]; then
   /usr/sbin/ethtool -K $PHYS_INT tx off 2>/dev/null || true
   fi
   touch /var/run/flannel-dns-fix.done
   EOF
   sudo chmod +x /usr/local/bin/flannel-dns-fix.sh
   cat <<'EOF' | sudo tee /etc/systemd/system/flannel-dns-fix.service
   [Unit]
   Description=Fix Flannel VXLAN TX Checksum Offload for DNS
   After=network.target
   ConditionPathExists=!/var/run/flannel-dns-fix.done
   [Service]
   Type=oneshot
   ExecStart=/usr/local/bin/flannel-dns-fix.sh
   RemainAfterExit=no
   EOF
   cat <<'EOF' | sudo tee /etc/systemd/system/flannel-dns-fix.timer
   [Unit]
   Description=Timer for Flannel DNS Fix
   [Timer]
   OnBootSec=30
   OnUnitActiveSec=10
   AccuracySec=1
   [Install]
   WantedBy=timers.target
   EOF
   sudo systemctl daemon-reload
   sudo systemctl enable flannel-dns-fix.timer
   sudo systemctl start flannel-dns-fix.timer
   sudo systemctl start flannel-dns-fix.service
   echo ""
   ethtool -k flannel.1 | grep tx-checksum

3. Verification (From Master), we should be able to see the newly added worker node by executing the 1st command:

   kubectl get nodes
   kubectl get pods -n kube-flannel -o wide