Add New Node to Cluster

Complete workflow to add a new node to the Kubernetes cluster via Tailscale.

Steps Overview

1. Discover the node on Tailscale
2. Add to Ansible inventory
3. Run bootstrap playbook
4. Run preflight checks
5. Add to cluster

Instructions

Step 1: Discover the Node

Check if the node is visible on Tailscale:

tailscale status | grep -i <node_name>

If not found, the user needs to install Tailscale on the target:

# On target node:
curl -fsSL https://tailscale.com/install.sh | sh
sudo tailscale up

Step 2: Get Node Details

Required information:

• Node name: Hostname (should match Tailscale name)
• Role: worker (default) or control-plane
• Reserved CPU: CPU cores for local use (default: "2")
• Reserved Memory: Memory to reserve (default: "4Gi")
• GPU: Has GPU? (default: false)
• Labels: Custom labels (optional)

Step 3: Update Inventory

Add to ansible/inventory/hosts.yml:

workers:
  hosts:
    <node_name>:
      ansible_host: <tailscale_ip>
      tailscale_ip: <tailscale_ip>
      reserved_cpu: "2"
      reserved_memory: "4Gi"
      node_labels:
        node-role: worker
        workstation: "true"

bootstrap:
  hosts:
    <node_name>: {}

Step 4: Setup SSH Access

Test connectivity:

ssh -o BatchMode=yes -o ConnectTimeout=5 <tailscale_ip> echo "SSH OK" 2>/dev/null

If fails:

ssh-copy-id <user>@<tailscale_ip>

Step 5: Run Bootstrap Playbook

cd /home/al/git/kubani
ansible-playbook -i ansible/inventory/hosts.yml ansible/playbooks/bootstrap_node.yml --limit <node_name>

Step 6: Run Preflight Checks

ansible-playbook -i ansible/inventory/hosts.yml ansible/playbooks/preflight_checks.yml --limit <node_name>

Step 7: Add Node to Cluster

Include control plane node to fetch join token:

ansible-playbook -i ansible/inventory/hosts.yml ansible/playbooks/add_node.yml --limit "<node_name>,sparky"

Step 8: Verify

KUBECONFIG=/home/al/.kube/config kubectl get nodes

Troubleshooting

• SSH failed: Run ssh-copy-id <user>@<ip> manually
• Bootstrap failed: Usually package or network issue
• Preflight failed: Missing Tailscale auth or network issues
• Add node failed: Check control plane health