How do you target a subset of clusters (e.g., only production)?

Label registered clusters (e.g., env=prod, region=eu) and use a cluster generator selector with matchLabels/matchExpressions to include only matching clusters. This lets one ApplicationSet deploy to just the intended fleet subset and automatically include new clusters that match the labels.

generators:
  - clusters:
      selector:
        matchLabels: { env: prod }