# platform/externaldns

**ExternalDNS** — automatic public DNS records for `public` services (Cloudflare).

- **Spec:** [docs/09 — DNS & Ingress](../../../home-network-k3s/docs/09-dns-and-ingress.md)
  (ExternalDNS is named in [docs/01](../../../home-network-k3s/docs/01-architecture-overview.md); no
  dedicated ADR)
- **Serves:** R-DNS-01/02/03
- **Owner:** WS-NET (token from WS-SEC)

## What this stub is

Flux `HelmRelease` watching Gateway/HTTPRoute + Service resources, publishing
`<service>.home.keithjackson.dev` records in Cloudflare from declared intent (no manual record
editing, R-DNS-02).

## Split-horizon note (docs/09)

A wildcard `*.keithjackson.dev` matches only one label deep, so `<svc>.home.keithjackson.dev` needs
its own record. **`internal` services need NO public record** — PiHole resolves them to the internal
Gateway VIP (split-horizon). ExternalDNS manages **`public`** services' records only.

## Public target + in-cluster DDNS (2026-10-03)

Gateway-published records are **CNAMEs to `wan.home.keithjackson.dev`**, not the Gateway VIP:

```
plex.home.keithjackson.dev  CNAME  wan.home.keithjackson.dev   <- external-dns (Gateway `target` annotation)
wan.home.keithjackson.dev   A      <current WAN IP>            <- cloudflare-ddns (ddns.yaml), every 5m
```

- The `target` annotation is on the **shared Gateway** (`platform/gateway/gateway.yaml`), so it
  applies to every route that publishes at all. `internal` routes (`controller: none`) still publish
  nothing.
- `ddns.yaml` runs `favonia/cloudflare-ddns` in this namespace with the same `cloudflare-api-token`.
  It detects the WAN IP through Cloudflare's trace endpoint, so the pod **must not** carry
  `egress-class: vpn`.
- LAN and pods resolve `*.home.keithjackson.dev` to the Gateway VIP via PiHole and CoreDNS
  (split-horizon) and never use the public path.
- **Nodes resolve through public DNS** (`node_baseline_dns_servers`), so from a node, the apiserver's
  OIDC issuer `keycloak.home.keithjackson.dev` resolves to the WAN IP. kubectl SSO therefore relies on
  the router hairpinning (NAT reflection) WAN:443 back to the Gateway.

Check: `dig +short @1.1.1.1 plex.home.keithjackson.dev` → `wan.home.keithjackson.dev.` then the WAN IP;
`kubectl -n external-dns logs deploy/cloudflare-ddns`.

## Secrets

Cloudflare API token referenced **by name** (`cloudflare-api-token`, shared with cert-manager),
**SOPS-encrypted** (WS-SEC, OQ-4).

## TODO (later phases)

- **Phase 2 (WS-NET):** confirm `gateway-httproute` source; prove an auto record for a test route
  (R-DNS-02, Phase-2 exit gate).
- **Phase 6 (WS-APPS):** PiHole provides the internal split-horizon answers as it onboards.