# Bookstore — Part 11 ch.06 "Multi-cluster & fleet": an ApplicationSet with a
# MATRIX generator — the Cartesian product of (clusters) × (git-directory
# environments). This is the "every environment on every region cluster"
# fleet topology in one object, and shows the matrix/git generators the
# chapter discusses (a step beyond the single cluster generator in 10-).
#
# WHEN MATRIX vs the simple CLUSTER generator (10-)
#   10- = ONE Application per cluster (cluster picks its overlay by label) —
#         the per-region or per-env-cluster topology.
#   THIS = clusters × environments — e.g. each REGION cluster runs dev AND
#         staging AND prod (or a chosen subset). Use the matrix when the
#         fleet axis and the environment axis are INDEPENDENT and you want
#         their product without hand-writing every combination.
#
# The GIT generator child enumerates directories under
# examples/bookstore/kustomize/overlays/ (dev, staging, prod) directly from
# the repo — so adding an overlay directory automatically adds an Application
# per cluster, no edit here (GitOps all the way down).
#
# !!! CRD-INTRINSIC DRY-RUN (identical precedent to argocd/ + 18-/51-/70-/83-)
#   `ApplicationSet` is `argoproj.io/v1alpha1`. WITHOUT Argo CD + the
#   ApplicationSet controller installed, a client dry-run prints
#     no matches for kind "ApplicationSet" in version "argoproj.io/v1alpha1"
#   EXPECTED, schema-correct (same precedent as examples/bookstore/argocd/).
#   Whole-dir dry-run prints this for CRD-backed files only and continues.
#   Schema verified against the Argo CD ApplicationSet matrix + git + clusters
#   generators.
#
# PLACEHOLDER: `repoURL` https://github.com/your-org/bookstore — replace
# `your-org` (same convention as examples/bookstore/argocd/). Paths are real.
#
# Requires: Argo CD installed; ≥1 fleet cluster registered+labelled (as 10-);
#   the `bookstore` AppProject.
# Apply (use EITHER 10- OR 20-, not both — they would both generate
# Applications targeting the same clusters/namespace; pick one topology, the
# same "alternative, not addition" rule as the Part 02 50-/51- pairing):
#   kubectl apply -n argocd -f examples/bookstore/multicluster/20-applicationset-matrix-generator.yaml
apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata:
  name: bookstore-fleet-matrix
  namespace: argocd
  labels:
    app.kubernetes.io/part-of: bookstore
spec:
  goTemplate: true
  goTemplateOptions: ["missingkey=error"]
  generators:
    - matrix:
        generators:
          # AXIS 1 — every fleet cluster (as in 10-).
          - clusters:
              selector:
                matchLabels:
                  bookstore.example.com/fleet: "true"
          # AXIS 2 — every overlay DIRECTORY in the repo (dev/staging/prod),
          # enumerated straight from Git. Adding overlays/<x>/ adds an
          # Application per cluster automatically.
          - git:
              repoURL: https://github.com/your-org/bookstore.git   # PLACEHOLDER — replace your-org
              revision: main
              directories:
                - path: examples/bookstore/kustomize/overlays/*
  template:
    metadata:
      # bookstore-<cluster>-<overlay-dir-basename>, unique per matrix cell.
      name: 'bookstore-{{.name}}-{{.path.basename}}'
      labels:
        app.kubernetes.io/part-of: bookstore
    spec:
      project: bookstore
      source:
        repoURL: https://github.com/your-org/bookstore.git         # PLACEHOLDER — replace your-org
        targetRevision: main
        path: '{{.path.path}}'             # the real overlay dir from the git axis
      destination:
        server: '{{.server}}'              # the cluster from the clusters axis
        # Per-environment namespace so dev/staging/prod can co-reside on one
        # cluster without colliding. The base ships `bookstore`; for the
        # matrix topology you would parametrize the namespace transformer per
        # overlay (out of scope to wire here — shown as the topology).
        namespace: bookstore
      syncPolicy:
        automated: { prune: true, selfHeal: true }
        syncOptions:
          - CreateNamespace=false          # base owns the PSA ns (Part 07 ch.04)