Added decision record for allowing arr apps to connect to plex

decisions/2026-10-01-arr-to-plex.md

@@ -0,0 +1,120 @@
+---
+date: 2026-10-01
+branch: bugfix/arr-to-plex
+title: Radarr and Sonarr may now reach Plex on 32400 — the network path only, not the Plex connection itself
+---
+
+## What changed
+
+Radarr and Sonarr had no route to Plex. The media library lives on NFS
+(`/mnt/Storage/plex`, the ZFS dataset `Storage/plex` on `${BULK_NFS_SERVER}`), and NFS
+does not deliver filesystem CRUD notifications, so Plex never learns that an arr has
+written a new file. Without a push from the arrs, the library only reflects new media
+when somebody scans it by hand. That is the bug this branch addresses.
+
+The fix is one `dependencies:` entry per app, added to the catalog — the source of truth:
+
+    - to: plex
+      port: 32400
+      protocol: tcp
+
+in both `catalog/radarr.yaml` and `catalog/sonarr.yaml` (these two *are* the arr suite
+here; `jackett`, `qbittorrent` and `seerr` are different roles and are untouched).
+
+The renderer expands each entry into a **pair** of Cilium policies, which is why a
+three-line catalog change produces 88 lines under `apps/`:
+
+| Side | Policy | File |
+|---|---|---|
+| egress | `radarr-allow-plex-32400` | `apps/wave-1/radarr.yaml` |
+| egress | `sonarr-allow-plex-32400` | `apps/wave-1/sonarr.yaml` |
+| reciprocal ingress | `plex-allow-radarr-32400` | `apps/wave-0/plex.yaml` |
+| reciprocal ingress | `plex-allow-sonarr-32400` | `apps/wave-0/plex.yaml` |
+
+Three commits, and the middle two are worth recording because both were self-inflicted
+gate failures rather than design changes:
+
+- `753c48b` — the catalog edit alone, with `apps/` left unrendered.
+- `9048c2f` — re-rendered `apps/` from the catalog, which `render==golden` requires.
+- `58f02fe` — removed 20 trailing spaces on `catalog/radarr.yaml:103`, left behind as
+  comment-alignment padding when the comment moved down to the `port:` line. Sonarr's
+  equivalent line kept its comment in place, which is why only radarr tripped.
+
+## What I verified
+
+**The lint failure, root-caused.** Gate run 193 on `9048c2f` failed with
+`[fail] lint: FAILED -> blocks merge`, and lint was the only failing stage. yamllint
+emitted 419 findings, but **418 were `line-length`**, which `ci/yamllint.yaml` pins at
+`level: warning` and which therefore cannot change the exit code. The single error-level
+finding in the entire repository was:
+
+    catalog/radarr.yaml
+      103:13    error    trailing spaces  (trailing-spaces)
+
+`trailing-spaces` inherits the default severity (error), so that one line returned rc 1.
+After the fix, `git grep -nIE ' +$' -- '*.yaml' '*.yml'` matches nothing repo-wide.
+
+**Gate run 195 on `58f02fe`** (read from the job log, not from the status tick):
+
+    [ ok ] approval-policy: green     [ ok ] l0: green
+    [ ok ] gitea-settings: green      [ ok ] render-golden: green
+    [ ok ] decisions-log: green       [ ok ] l1: green
+    [ ok ] lint: green
+    [fail] MERGE GATE: UNDETERMINED — greenness was NOT ESTABLISHED.
+    [fail]   Stages that did not run: spec-immutability
+
+The Gitea check reports `success` / "Successful in 1m41s", but the gate's own verdict is
+**UNDETERMINED (rc 3)**, not PASS. That tick is `gate.yml` tolerating exit 3 for the one
+stage it documents as unverifiable on this runner (the spec repo is not checked out
+there). Nothing else produced a 3.
+
+**`render==golden` green** on `58f02fe`, so `apps/` is a faithful canonical render of
+`catalog/` — the four generated policies are not hand-written drift.
+
+**DNS egress was already open** and is not a new gap: `apps/wave-1/radarr.yaml` carries
+an existing allow for port 53 UDP+TCP, so resolving the Plex service name does not need
+anything added here.
+
+**Live branch protection on `main`**, measured against
+`/api/v1/repos/Home-Network/home-network-k3s-impl/branches/main` rather than assumed:
+`protected: true`, `user_can_push: false`, `enable_status_check: true`,
+`status_check_contexts: ['gate / gate (pull_request)']`, `required_approvals: 1`.
+
+## What I did NOT verify
+
+**This change does not accomplish what the PR set out to do.** It opens the network path
+and nothing else. Triggering a library update also requires each arr's
+*Settings → Connect → Plex Media Server* entry plus a Plex token, and **none of that
+exists anywhere in `catalog/` or `apps/`** — I grepped both for `plex`, `token` and
+`connect` and found only NFS paths, a uid and a timezone. Radarr's and Sonarr's config
+lives on a 5Gi Longhorn PVC mounted at `/config`, so that connection is UI-only state
+that exists solely on the PVC and never in git, in the same way Crafty's local login
+does. **Until somebody adds it in each app's UI, Plex still will not see library
+updates, and this branch will look like it did nothing.** That follow-up is not tracked
+by any file in this PR.
+
+**L2/L3 conformance never ran.** `CLUSTER_AVAILABLE` is unset on the runner, so the
+eight requirements this diff touches — `R-NET-01`, `R-NET-05`, `R-NET-06`, `R-NET-07`,
+`R-IDP-02`, `R-IDP-06`, `R-GITOPS-02`, `R-PLAT-02` — are **UNVERIFIED**. That gap is
+unusually load-bearing here: the entire substance of this change is four
+CiliumNetworkPolicies, and no test has confirmed that traffic from the `radarr` or
+`sonarr` namespaces actually reaches `plex:32400`. The green gate proves the offline
+render subset only.
+
+**`spec-immutability` did not run** (`R-TEST-06` not verified), for the documented
+reason — the sibling spec repo is absent from the runner.
+
+**Nothing was checked on the cluster.** I ran no `kubectl`, so I did not confirm that
+the `plex` Service exposes 32400 as the arrs would address it, that the pod labels the
+policies select (`app.kubernetes.io/name`, `k8s:io.kubernetes.pod.namespace`) match the
+running pods, or that Cilium accepted the four new objects. Flux has not applied any of
+this: the branch is unmerged, so `.status.lastAppliedRevision` does not contain it.
+
+**I did not verify Plex's own side** — whether its library-update endpoint on 32400 is
+the right target for the arrs' notification, or whether Plex requires
+"Update my library automatically" enabled to act on one.
+
+**I am not the approver and did not approve this PR.** `required_approvals: 1` is live,
+and the only credential on the authoring workstation belongs to the PR's author
+(`jakman85`), whose own review Gitea does not count. Per CLAUDE.md §1 the merge is a
+human action regardless.