What does the nodeSelector field in a PodSpec use to place Pods on specific nodes?

What does the nodeSelector field in a PodSpec use to place Pods on specific nodes?

• A. The Node's labels
• B. Labels assigned to Nodes
• C. The Pod's labels
• D. The Pod's annotations

Answer: (B)

NodeSelector uses the labels on nodes to decide where a pod can run. When a pod specifies a nodeSelector, it lists required key-value pairs, and the scheduler will place the pod only on nodes that have matching labels. For example, if a node has labels like environment=production and disk=ssd, and the pod’s nodeSelector requires those same pairs, the pod can be scheduled there. If no nodes have the matching labels, the pod remains pending until a suitable node appears or labels are added. Pod labels or annotations aren’t involved in this scheduling rule, since the selector relies on node metadata rather than pod metadata. If you need more flexibility, you can use nodeAffinity, which offers more nuanced scheduling rules.

NodeSelector uses the labels on nodes to decide where a pod can run. When a pod specifies a nodeSelector, it lists required key-value pairs, and the scheduler will place the pod only on nodes that have matching labels. For example, if a node has labels like environment=production and disk=ssd, and the pod’s nodeSelector requires those same pairs, the pod can be scheduled there. If no nodes have the matching labels, the pod remains pending until a suitable node appears or labels are added. Pod labels or annotations aren’t involved in this scheduling rule, since the selector relies on node metadata rather than pod metadata. If you need more flexibility, you can use nodeAffinity, which offers more nuanced scheduling rules.