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home-network-k3s-impl/platform/crafty/README.md
jakman85andClaude Opus 4.8 0437871807 Onboard Crafty Controller (Minecraft panel) with Keycloak-gated web UI
Add Crafty Controller 4 (registry.gitlab.com/crafty-controller/crafty-4:4.10.8)
as a platform component: a web panel that runs Java + Bedrock Minecraft servers as
subprocesses in one pod + a 20Gi Longhorn PVC (mounted 5x by subPath).

Auth = Option B (per-app oauth2-proxy reverse-proxy sidecar), since Cilium 1.16.5
cannot do ext_authz on the shared Gateway:
- oauth2-proxy v7.8.1 sidecar (:4180) reverse-proxies to Crafty's self-signed HTTPS
  UI (127.0.0.1:8443), gated to Keycloak homelab realm group platform-admins.
- Confidential `crafty` client provisioned live via kcadm + captured in the realm
  import; client secret + cookie secret via SOPS/age (mirrored in realm-clients).

- Web UI: HTTPRoute crafty.home.keithjackson.dev -> Service :80 -> sidecar :4180.
- Game ports: Cilium L2 LoadBalancer on VIP 192.168.1.55 (next free after .53/.54),
  starter set TCP 25565-25567 (Java) + UDP 19132-19134 (Bedrock), NOT auth-gated.
- fsGroup:0 / runAsGroup:0 / runAsUser:1000 for the image's crafty:root identity on
  the root:root Longhorn PVC (the seerr fsGroup lesson).
- Own non-gating Flux tier clusters/base/crafty.yaml (dependsOn platform-config,
  wait:false) + sops-decryption patch in clusters/dev — a leaf UI must never gate
  the platform.
- Explicit default-deny NetworkPolicy + CiliumNetworkPolicies (platform namespace,
  not app-namespace, so Kyverno does not auto-generate the baseline).

make -C ci gate green; kustomize build of platform/crafty, clusters/base,
clusters/dev clean.

Co-Authored-By: Claude Opus 4.8 <[email protected]>
2026-08-28 15:39:51 -05:00

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# platform/crafty
**Crafty Controller 4** — a web panel that creates and manages multiple Minecraft servers (Java +
Bedrock) as **subprocesses inside its own container**. Its web UI is **Keycloak-gated** via a per-pod
**oauth2-proxy reverse-proxy sidecar** (the decided **Option B**, see
[`../oauth2-proxy/README.md`](../oauth2-proxy/README.md)). Game ports are exposed **un-gated** on a
Cilium L2 LoadBalancer (game protocols authenticate players themselves).
- **Owner:** WS-APP (auth wiring shared with WS-SEC)
- **Flux tier:** own non-gating `clusters/base/crafty.yaml` (`dependsOn platform-config`, `wait:false`)
- **Namespace:** `crafty` (PLATFORM namespace — `gateway-access=shared`, NOT `app-namespace=true`)
## Deploy summary
| Thing | Value |
|---|---|
| Image | `registry.gitlab.com/crafty-controller/crafty-4:4.10.8` (current stable; bare-semver tags, no `v`) |
| Web UI | HTTPS **self-signed** on `:8443` (reached only via the sidecar / same-pod) |
| Sidecar | `quay.io/oauth2-proxy/oauth2-proxy:v7.8.1`, reverse-proxy on `:4180` |
| Data | ONE Longhorn RWO PVC `crafty-data` (20Gi), mounted 5× by subPath |
| PVC subPaths | `servers`→`/crafty/servers`, `backups`→`/crafty/backups`, `logs`→`/crafty/logs`, `import`→`/crafty/import`, `config`→`/crafty/app/config` |
| Identity | `runAsUser:1000 runAsGroup:0 fsGroup:0 runAsNonRoot:true` (see below) |
| Web host | `crafty.home.keithjackson.dev` → shared Gateway → `crafty` Service :80 → sidecar :4180 → Crafty :8443 |
| Game VIP | **192.168.1.55** (Cilium L2 LoadBalancer; `.53`=Gateway, `.54`=unifi, `.55`=crafty) |
| Game ports | starter set: **TCP 25565-25567** (Java), **UDP 19132-19134** (Bedrock) |
### fsGroup / user decision (the seerr lesson, applied)
Crafty's Dockerfile does `useradd -g root -M crafty` (UID **1000**, primary group **root/GID 0**),
`chown -R crafty:root /crafty`, and makes `/crafty` group-writable — the OpenShift/K8s
"arbitrary-UID, root-group-perms" pattern. A fresh Longhorn PVC is `root:root` and not group-writable,
so the non-root crafty process could not create `/crafty/servers/*` etc. and would CrashLoop (exactly
seerr's failure at UID 1000 on a `root:root` PVC). Fix: **`fsGroup: 0`** makes the kubelet group-own
the mounted volume to GID 0, mark it group-writable+SGID, and add GID 0 as a supplemental group;
**`runAsGroup: 0`** + **`runAsUser: 1000`** pin the image's own `crafty:root` identity. Longhorn's
`CSIDriver fsGroupPolicy: ReadWriteOnceWithFSType` applies fsGroup to this RWO filesystem volume.
> **HUMAN runtime check:** confirm the pod writes its SQLite DB and can start a server. If the image's
> `crafty` UID is ever not 1000, adjust `runAsUser` (the launcher's non-root path runs directly as the
> current UID, so any non-root UID with GID 0 works, but 1000 matches `getpwuid` cleanly).
## Auth = Option B (per-app oauth2-proxy reverse-proxy)
Cilium 1.16.5 cannot inject `ext_authz` into the shared Gateway's machine-generated Envoy config, and
native Gateway-API ExternalAuth ships in no released Cilium yet (see `../oauth2-proxy/README.md`). So
Crafty's UI is gated by a **dedicated oauth2-proxy sidecar in the Crafty pod** (`--reverse-proxy`,
`--upstream=https://127.0.0.1:8443`, `--ssl-upstream-insecure-skip-verify=true`,
`--allowed-groups=platform-admins`, `--skip-provider-button`, cookie/redirect for
`crafty.home.keithjackson.dev`). The `crafty` Service targets the sidecar, never Crafty's `:8443`, so
the gate is **in the data path** (fail-closed: no valid `platform-admins` session ⇒ no upstream).
> **Note:** Crafty ALSO has its own local admin login (it has no OIDC). After oauth2-proxy admits the
> user, they still see Crafty's own login page — a second, defense-in-depth factor. The operator logs
> in with Crafty's local admin credentials (set on first boot). This is expected, not a bug.
### Keycloak client
Confidential auth-code client **`crafty`** in the `homelab` realm — redirect
`https://crafty.home.keithjackson.dev/oauth2/callback`, `webOrigins` the same host, a `groups`
membership mapper (bare names). Provisioned **live via kcadm** at authoring time (2026-08-28) and
captured as the durable GitOps source of truth in
[`../keycloak/keycloak-realm-import.yaml`](../keycloak/keycloak-realm-import.yaml) (secret injected via
the `CRAFTY_CLIENT_SECRET` placeholder).
### Secret locations (SOPS/age)
| Secret | File | Key |
|---|---|---|
| oauth2-proxy client id/secret + cookie secret | `crafty-oauth2-proxy-credentials.sops.yaml` (this dir) | `client-id`, `client-secret`, `cookie-secret` |
| Keycloak client secret (mirror) | `../keycloak/keycloak-realm-clients.sops.yaml` | `crafty-client-secret` |
`client-secret` here **must equal** `crafty-client-secret` there (cross-namespace mirror — a Secret
can't span namespaces). Both are age-encrypted to the repo `sops-age` recipient and Flux-decryptable
(verified: both decrypt and the two values match).
## Game-port L4 exposure
The Gateway is L7-HTTPS-only; raw TCP/UDP game ports can't ride it. `service-l4.yaml` exposes them as
two `type=LoadBalancer` Services (TCP + UDP) sharing the pinned VIP **192.168.1.55**
(`lbipam.cilium.io/sharing-key: crafty`), ARP-announced by the existing `default-l2` policy. This path
is **NOT auth-gated** — Minecraft Java (Mojang/Microsoft) and Bedrock (Xbox Live) authenticate players
themselves. `external-dns` publishes `crafty-mc.home.keithjackson.dev → 192.168.1.55`.
### Adding more game ports (when the operator creates servers)
The operator has **not created any servers yet**; the starter set covers 3 Java + 3 Bedrock slots. To
add capacity:
1. In the Crafty UI, create the server and bind it to a NEW port (Java TCP or Bedrock UDP).
2. Add that port to the matching Service in `service-l4.yaml` (one
`{ name, port, targetPort, protocol }` line — K8s Services enumerate ports, no ranges).
3. Add it to the game-port ingress rule in `networkpolicy.yaml` (`crafty-allow-ingress`).
4. (Optional) add a `containerPort` in `deployment.yaml` for documentation.
5. Commit → Flux reconciles.
## Policies
`namespace.yaml` sets only `gateway-access=shared` (platform namespace, like headlamp/homepage), so
Kyverno does not auto-generate the app baseline. `networkpolicy.yaml` ships it explicitly (defense in
depth): default-deny (DNS-only egress) + Cilium allows — Gateway→sidecar `:4180`, world/LAN→game
ports, host→probe ports, and egress `world` (server-jar downloads + the OIDC path to Keycloak via the
Gateway VIP). The sidecar→Crafty hop is pod-local (`127.0.0.1`) and not subject to network policy.
## Verification
- `make -C ci gate` — green (hand-authored platform manifests; render-golden unaffected).
- `kustomize build` of `platform/crafty`, `clusters/base`, `clusters/dev` — clean.
### Human tests (post-deploy)
1. **Browser OIDC round-trip:** incognito → `https://crafty.home.keithjackson.dev` → expect a 302 to
`https://keycloak.home.keithjackson.dev/realms/homelab/...` (NOT the Crafty UI). Log in as a
**platform-admins** user (MFA/OTP enforced) → land on Crafty's own login → sign in with Crafty's
local admin. A **non-platform-admins** user → **403** (authenticated but not authorized).
2. **Pod health / fsGroup:** `kubectl -n crafty get pod` Ready 2/2; Crafty writes its DB under
`/crafty/app/config` and `/crafty/servers` without EACCES.
3. **Server-create + game reach:** in the Crafty UI create a Java server bound to `25565`; start it;
connect a Minecraft client to `crafty-mc.home.keithjackson.dev:25565` (or `192.168.1.55:25565`)
from the LAN and confirm the world loads. (Bedrock: a server on `19132/udp` reached at the VIP.)