feat(storage): the bulk tier becomes real — static NFS PVs, authored once per environment

The `bulk` class has existed since Phase 0 as a deliberate stub: the StorageClass named an NFS
CSI driver that is not installed and a server/share of REPLACE-ME, so plex, sonarr, radarr and
qbittorrent all carry a comment saying "attach the library once OQ-2 is resolved". This is that
resolution — for the case that actually exists here, which is NOT the case the stub anticipated.

The stub assumed DYNAMIC provisioning: ask a CSI driver for a bulk volume and get a fresh empty
subdirectory. That is the wrong shape for this platform's bulk data. The media library is 8.33 TiB
that already exists, on ZFS datasets on the Proxmox host, with live non-k3s consumers. Nothing
needs provisioning; existing datasets need ATTACHING. So a bulk storage entry now renders a
STATIC, pre-bound NFS PersistentVolume plus its PVC, and needs no CSI driver at all (the in-tree
NFS volume source is not deprecated and has no CSI migration).

Schema 1.4.0 adds, on a storage entry:
  export     absolute NFS export path; REQUIRED when class is bulk, FORBIDDEN otherwise (an `if`
             in the schema, so a bulk entry cannot be authored without saying what it attaches).
  subPath    mount a subtree instead of the volume root — any class.
  readOnly   any class; on bulk it also sets the PV's nfs.readOnly, so the mount really is `ro`.

The SERVER is deliberately NOT a schema field. It is the `${BULK_NFS_SERVER}` cluster-vars knob,
because dev and prod reach the SAME storage host by different addresses and R-ENV-02 says the
service definition is authored once. A ServiceDefinition says WHICH dataset; the overlay says
where the host is.

Three decisions worth the reader's time, argued in full in the r_bulk_pvs docstring:

  * PV/PVC, not an inline `nfs:` pod volume. Inline is fewer objects and would work. It cannot
    express `persistentVolumeReclaimPolicy: Retain`, which is the one property most worth having
    in git for 8.33 TiB of data with consumers outside this cluster; it puts read-only enforcement
    one Deployment edit away from silent removal; and it is invisible to `kubectl get pv,pvc`,
    which is where an operator looks for attached external storage.
  * storageClassName: "" on both ends, NOT the `bulk` StorageClass. Explicitly empty is the
    canonical marker for a statically provisioned volume. It also sidesteps a trap: a
    StorageClass's `provisioner` is IMMUTABLE, so re-pointing the deployed `bulk` stub would make
    Flux fail on that object forever.
  * Access mode is always `…Many` and follows the read/write posture — ReadOnlyMany for a reader,
    ReadWriteMany for a writer. One export is consumed by several namespaces AND several nodes at
    once, which is exactly what ReadWriteOnce cannot express; which `Many` it is then makes the
    intent legible in `kubectl get pv`.

mountOptions are a platform decision held in the renderer rather than a per-service field:
nfsvers=4.1,hard,noatime,timeo=600,retrans=2. NFSv4 carries mount and lock in-protocol, so the
only port that must be reachable is tcp/2049 — no rpcbind/111, mountd or statd. That is a
firewall decision as much as a storage one. `hard` over `soft` because a soft mount converts a
server hiccup into a short read handed to the application.

The contract doc records the trap that will otherwise be discovered in production: fsGroup is a
NO-OP on an NFS volume (the in-tree plugin does no ownership management), so a writable bulk mount
requires the container's own uid/gid to suit the export's ownership. A mount that succeeds and
then cannot write is this tier's characteristic failure.

Every pre-existing golden renders byte-identical: the new keys are emitted only when declared, and
`readOnly` defaults to False. render-golden: 10/10. selftest: PASS.

Co-Authored-By: Claude Opus 5 <[email protected]>

catalog/render.py

@@ -53,6 +53,30 @@ LBL = "homelab.keithjackson.dev"
 # Hardcoding the literal here is what let prod be authored to serve dev's public hostnames,
 # and prod's external-dns then deleted dev's records (infra/PROD-PROVISIONING.md §10).
 ZONE = "${BASE_DOMAIN}"
+# The bulk (external NFS) tier's SERVER, emitted as a Flux post-build TOKEN for exactly the same
+# reason as ZONE: dev and prod reach the same Proxmox ZFS host by DIFFERENT addresses (dev's nodes
+# are on the host's own LAN and dial it directly; prod's nodes are on the far side of pfSense and
+# must be given whichever address the still-pending routing decision produces). Hardcoding either
+# one authors a manifest that is silently wrong in the other environment. Declared in
+# clusters/base/cluster-vars.yaml and patched by BOTH overlays; written BARE (it is a real knob,
+# not a shell expansion), so StrictPostBuildSubstitutions fails the tier if an overlay forgets it.
+BULK_NFS_SERVER = "${BULK_NFS_SERVER}"
+# Mount options for every bulk NFS volume. These are a PLATFORM decision, not a per-service one,
+# so they live here rather than on the ServiceDefinition surface:
+#   nfsvers=4.1  NFSv4 carries mount+lock IN the protocol, so it needs ONE port (tcp/2049) and no
+#                rpcbind/111, mountd or statd. That is what makes the prod path a single pfSense
+#                rule instead of four, and it is why v4 is chosen over v3. The server advertises
+#                +3 +4 +4.1 +4.2; 4.1 is the conservative floor every node kernel already speaks.
+#   hard         A `soft` mount turns a server hiccup into a short read / EIO handed to the
+#                application, which for a media library and an archive is silent corruption.
+#                `hard` blocks instead. The cost is explicit: an NFS outage HANGS I/O rather than
+#                failing it, so an outage shows up as stuck pods, not as damaged files. Chosen
+#                deliberately -- hung is recoverable, truncated is not.
+#   noatime      The datasets are relatime, so every read would otherwise generate a metadata
+#                WRITE back to the pool. Plex walking an 8 T library must not do that.
+#   timeo=600/retrans=2  the TCP defaults, stated explicitly so a future reader knows the retry
+#                budget was considered rather than inherited.
+BULK_NFS_MOUNT_OPTIONS = ["nfsvers=4.1", "hard", "noatime", "timeo=600", "retrans=2"]
 GATEWAY_NAME = "shared"
 GATEWAY_NS = "gateway"
 KP_RELEASE = "kube-prometheus-stack"  # ServiceMonitor/PrometheusRule discovery label
@@ -111,8 +135,10 @@ def apply_defaults(sd: dict) -> dict:
     obs.setdefault("slis", [])
     s["observability"] = obs
 
-    # storage entry class default is longhorn (replicated tier).
-    s["storage"] = [{**{"class": "longhorn"}, **v} for v in s["storage"]]
+    # storage entry class default is longhorn (replicated tier); readOnly default is False
+    # (grant-nothing-extra is expressed by SETTING it, so the default stays back-compatible and
+    # every pre-existing golden renders byte-identical).
+    s["storage"] = [{**{"class": "longhorn", "readOnly": False}, **v} for v in s["storage"]]
     # dependency protocol default is tcp.
     s["dependencies"] = [{**{"protocol": "tcp"}, **d} for d in s["dependencies"]]
     return s
@@ -200,18 +226,125 @@ def _service_ports(s: dict) -> list:
     return [{"name": f"port-{p}", "port": p, "targetPort": p} for p in ports]
 
 
+def _bulk_access_mode(vol: dict) -> str:
+    """A bulk volume's access mode follows its read/write posture.
+
+    Every bulk volume is `...Many`: the SAME export is consumed by several namespaces at once
+    (plex, sonarr and radarr all sit on /mnt/Storage/plex) and by several nodes at once, which is
+    precisely what ReadWriteOnce cannot express. WHICH `Many` it is says whether this consumer
+    writes -- so `kubectl get pv` reports the intent, not merely the topology.
+    """
+    return "ReadOnlyMany" if vol.get("readOnly") else "ReadWriteMany"
+
+
+def r_bulk_pvs(s: dict) -> list:
+    """One STATIC PersistentVolume per `class: bulk` storage entry (docs/04 bulk tier).
+
+    WHY A PV AT ALL, RATHER THAN AN INLINE `nfs:` POD VOLUME
+    -------------------------------------------------------
+    An inline volume is fewer objects and it would work. It is rejected for four reasons, in
+    descending order of what they would cost to discover later:
+
+      1. RECLAIM POLICY. `persistentVolumeReclaimPolicy: Retain` is a declared, reviewable
+         property of a PV. There is no equivalent for an inline volume -- and the data behind
+         these mounts is 8.33 TiB of media and a 267 GiB archive that ALSO has live non-k3s
+         consumers. A statement in git that nothing in this cluster may reclaim it is worth an
+         object.
+      2. READ-ONLY LIVES IN ONE PLACE. `spec.nfs.readOnly: true` becomes a real `ro` mount option
+         for every pod that ever binds this volume. The same intent expressed on an inline volume
+         is one Deployment edit away from being dropped silently, with no diff anywhere near the
+         storage. (It is still a CLIENT-side guarantee -- the export cannot distinguish plex from
+         sonarr, since both may run on any node -- but it is one that lives in one reviewable
+         place.)
+      3. VISIBILITY. `kubectl get pv,pvc` is where an operator looks for "what external storage is
+         attached, and who holds it". An inline volume is invisible there, and invisible to
+         anything that reasons over PVCs.
+      4. IT IS THE CONTRACT THE REPO ALREADY HAS. Every other storage entry is a PVC; the
+         renderer, the Kyverno ServiceDefinition policy and the backup wiring all key on that. An
+         inline volume would be a second, parallel storage model inside the same renderer.
+
+    CROSS-NAMESPACE. A PV binds 1:1 to a PVC, so "plex, sonarr and radarr share one export" is NOT
+    one shared PV -- it is three PVs, one per namespace, each naming the same server+path. That is
+    the correct model rather than a workaround: the sharing happens on the NFS server, which is
+    built for concurrent clients, and each namespace keeps its own independently reviewable access
+    mode (plex ReadOnlyMany, the arrs ReadWriteMany). One shared PV would have forced a single
+    posture on all three.
+
+    BINDING IS PINNED FROM BOTH ENDS -- `claimRef` here and `volumeName` on the PVC. Either alone
+    leaves a race in which some other PVC of matching size and mode grabs the volume first;
+    together the binding is deterministic. `storageClassName: ""` (explicitly empty, NOT the `bulk`
+    StorageClass) is what tells the binder this volume is statically provisioned: it suppresses the
+    default-StorageClass annotation and guarantees no provisioner is ever asked to create anything.
+    It also sidesteps a trap -- a StorageClass's `provisioner` is IMMUTABLE, so re-pointing the
+    existing `bulk` class (whose stub names an NFS CSI driver that is not installed) at this data
+    would make Flux fail forever on that one object.
+    """
+    out = []
+    for vol in s["storage"]:
+        if vol.get("class") != "bulk":
+            continue
+        name = f"{s['name']}-{vol['name']}"
+        nfs = {"server": BULK_NFS_SERVER, "path": vol["export"]}
+        if vol.get("readOnly"):
+            nfs["readOnly"] = True
+        spec = {
+            "capacity": {"storage": vol["size"]},
+            "accessModes": [_bulk_access_mode(vol)],
+            # Retain: deleting the PVC must NEVER be able to reach the data. There is nothing to
+            # "reclaim" here in any case -- the volume was not provisioned by the cluster.
+            "persistentVolumeReclaimPolicy": "Retain",
+            "storageClassName": "",
+            "mountOptions": list(BULK_NFS_MOUNT_OPTIONS),
+            "nfs": nfs,
+            "claimRef": {"namespace": s["name"], "name": name},
+        }
+        out.append(
+            {
+                "apiVersion": "v1",
+                "kind": "PersistentVolume",
+                "metadata": {
+                    "name": name,
+                    "labels": {"app.kubernetes.io/name": s["name"]},
+                },
+                "spec": spec,
+            }
+        )
+    return out
+
+
 def r_pvcs(s: dict) -> list:
     """One PVC per storage entry (R-STATE-01/02/04).
 
-    longhorn -> 3-replica replicated tier; bulk -> external media tier (not 3x replicated).
+    longhorn -> 3-replica replicated tier, dynamically provisioned, ReadWriteOnce.
+    bulk     -> the STATIC external NFS PV rendered by r_bulk_pvs, pre-bound by volumeName.
     """
     out = []
     for vol in s["storage"]:
         cls = vol.get("class", "longhorn")
-        storage_class = "longhorn" if cls == "longhorn" else "bulk"
+        if cls == "bulk":
+            # Mirror image of the PV: the same explicitly-empty class (so nothing dynamically
+            # provisions), the same access mode, and volumeName completing the two-sided binding.
+            out.append(
+                {
+                    "apiVersion": "v1",
+                    "kind": "PersistentVolumeClaim",
+                    "metadata": {
+                        "name": f"{s['name']}-{vol['name']}",
+                        "namespace": s["name"],
+                        "labels": {"app.kubernetes.io/name": s["name"]},
+                    },
+                    "spec": {
+                        "accessModes": [_bulk_access_mode(vol)],
+                        "storageClassName": "",
+                        "volumeName": f"{s['name']}-{vol['name']}",
+                        "resources": {"requests": {"storage": vol["size"]}},
+                    },
+                }
+            )
+            continue
         spec = {
             "accessModes": ["ReadWriteOnce"],
-            "storageClassName": storage_class,
+            "storageClassName": "longhorn",
         }
         if vol.get("size"):
             spec["resources"] = {"requests": {"storage": vol["size"]}}
@@ -257,7 +390,17 @@ def r_deployment(s: dict) -> dict:
         # it verbatim for apps that need a fixed on-disk layout (e.g. Gitea keeps all state
         # directly under /data). Omitting it preserves the /data/<name> default (back-compat).
         mount_path = vol.get("mountPath", f"/data/{vol['name']}")
-        volume_mounts.append({"name": vol["name"], "mountPath": mount_path})
+        mount = {"name": vol["name"], "mountPath": mount_path}
+        # subPath mounts a subtree of the volume instead of its root. Emitted only when declared,
+        # so every pre-existing golden stays byte-identical.
+        if vol.get("subPath"):
+            mount["subPath"] = vol["subPath"]
+        # readOnly on the mount as well as on the PV's nfs source. Belt and braces on purpose: the
+        # PV field is what makes the kernel mount `ro`; this one is what a reviewer reading the
+        # Deployment sees. An edit that drops one still leaves the other.
+        if vol.get("readOnly"):
+            mount["readOnly"] = True
+        volume_mounts.append(mount)
         volumes.append(
             {
                 "name": vol["name"],
@@ -1095,6 +1238,14 @@ def render(sd: dict, image_automation: bool = True, inbound: list | None = None)
     if s["kind"] == "container":
         # Container PVCs. (For a vm, the CDI DataVolume owns/creates the disk PVC, so we
         # never render a plain PVC for the VM root disk — it would collide with CDI.)
+        # The static bulk PV is rendered BEFORE the PVC that names it. Document order inside one
+        # kustomize build is not an apply-ordering guarantee, but a PVC whose PV does not exist
+        # yet merely stays Pending and binds on the next reconcile, so this is a readability
+        # convention rather than a correctness requirement.
+        for pv in r_bulk_pvs(s):
+            docs.append(
+                (f"PersistentVolume {pv['metadata']['name']} - static external NFS (bulk tier)", pv)
+            )
         for pvc in r_pvcs(s):
             docs.append((f"PVC {pvc['metadata']['name']} (R-STATE)", pvc))
         docs.append(("Deployment (R-PLAT-02)", r_deployment(s)))