{
  "id": "node-cordon-basics",
  "title": "Cordoning and Uncordoning a Node",
  "category": "Cluster Management",
  "difficulty": "Easy",
  "type": "task",
  "weight": 4,
  "description": "## Cordoning and Uncordoning a Node\n\n`kubectl cordon` marks a node as **unschedulable** — the node continues running existing workloads but the scheduler will not place new pods on it. This is useful before maintenance windows.\n\n`kubectl uncordon` reverses the cordon, making the node schedulable again.\n\n**Your task:**\n\n1. Find the name of the cluster node using `kubectl get nodes`\n2. **Cordon** the node\n3. Verify the node shows `SchedulingDisabled` in its status\n4. **Uncordon** the node to restore it to normal\n\n```bash\n# Check node status:\nkubectl get nodes\n\n# Cordon:\nkubectl cordon <node-name>\n\n# Uncordon:\nkubectl uncordon <node-name>\n```",
  "hints": [
    {
      "title": "Find the node name",
      "body": "In this single-node cluster, there is exactly one node. Use kubectl get nodes to find its name.",
      "command": "kubectl get nodes -o jsonpath='{.items[0].metadata.name}'"
    },
    {
      "title": "Cordon and uncordon using a variable",
      "body": "Store the node name in a variable for convenience, then cordon and uncordon it.",
      "command": "NODE=$(kubectl get nodes -o jsonpath='{.items[0].metadata.name}') && kubectl cordon $NODE && kubectl uncordon $NODE"
    }
  ],
  "setup_commands": [],
  "validation": {
    "commands": [
      {
        "description": "Node is schedulable (not cordoned)",
        "command": "kubectl get nodes -o jsonpath='{.items[0].spec.unschedulable}' 2>/dev/null || echo 'false'",
        "expected_output": "false",
        "match": "contains"
      },
      {
        "description": "Node is in Ready state",
        "command": "kubectl get nodes -o jsonpath='{.items[0].status.conditions[?(@.type==\"Ready\")].status}'",
        "expected_output": "True",
        "match": "exact"
      }
    ]
  },
  "default_namespace": "default",
  "teardown_commands": [
    {
      "command": "kubectl uncordon $(kubectl get nodes -o jsonpath='{.items[0].metadata.name}') 2>/dev/null || true"
    }
  ]
}