fix service subdomains env var not working

apps/ns/README.md

@@ -7,11 +7,18 @@ discover every service host (Accounts, API, Auth, Econ, Matchmaking,
 Notifications, …).
 
 Each host is built at runtime from the `DOMAIN` var (the base domain) plus the
-service → subdomain map in `src/endpoints.ts`. `DOMAIN` is injected at deploy
-time from `RECFLARE_DOMAIN` (see `run-wrangler-deploy`) and defaults to
-`rec.example.com` in `wrangler.jsonc` for local dev.
+service → subdomain map in `src/endpoints.ts`, with the `SUBDOMAINS` var applied
+on top. Both vars are injected at deploy time from `RECFLARE_DOMAIN` and
+`RECFLARE_SUBDOMAINS` (see `run-wrangler-deploy`) and default to
+`rec.example.com` / `{}` in `wrangler.jsonc` for local dev.
 
 ## Updating endpoints
 
 - To change the base domain, set `RECFLARE_DOMAIN` (in `.env`) and redeploy.
-- To add or rename a service host, edit the map in `src/endpoints.ts`.
+- To point one service at a different host, add it to `RECFLARE_SUBDOMAINS` (in
+  `.env`) and redeploy. It's keyed by the service's _default_ subdomain — the
+  same object `run-wrangler-deploy` reads to pick a worker's host, so an entry
+  moves the deployed worker and the advertised host together. An entry for a
+  service with no worker (e.g. `{"moderation":"api"}`) is a pure client-side
+  redirect onto a host another worker already serves.
+- To add or rename a service, edit the map in `src/endpoints.ts`.

apps/ns/src/context.ts

@@ -8,6 +8,14 @@ export type Env = SharedHonoEnv & {
 	 * for local dev and tests.
 	 */
 	DOMAIN: string
+
+	/**
+	 * Per-service subdomain overrides as a raw JSON object keyed by default subdomain,
+	 * e.g. `{"moderation":"api"}`. The operator's `RECFLARE_SUBDOMAINS`, injected at deploy
+	 * time via `--var SUBDOMAINS`; defaults to `{}` in `wrangler.jsonc`. See
+	 * `parseOverrides` in `endpoints.ts`.
+	 */
+	SUBDOMAINS: string
 }
 
 /** Variables can be extended */

apps/ns/src/endpoints.ts

@@ -1,9 +1,11 @@
 /**
- * Service-discovery map: service label → subdomain. The game client fetches the
+ * Service-discovery map: service label → default subdomain. The game client fetches the
  * generated `{ label: "https://<subdomain>.<domain>" }` document from `/`.
  *
  * The base domain is injected at deploy time via the `DOMAIN` var (see
- * `run-wrangler-deploy`), so the real domain never lives in a versioned file.
+ * `run-wrangler-deploy`), so the real domain never lives in a versioned file. The
+ * subdomains here are defaults — an operator redirects any of them from `.env`, see
+ * `applyOverrides` below.
  */
 const SERVICE_SUBDOMAINS = {
 	Accounts: 'accounts',
@@ -44,9 +46,48 @@ const SERVICE_SUBDOMAINS = {
 	WWW: 'www',
 } as const
 
-/** Builds the endpoints document for `domain`, e.g. `rec.example.com`. */
-export function buildEndpoints(domain: string): Record<string, string> {
+/**
+ * Parses the `SUBDOMAINS` var — the operator's `RECFLARE_SUBDOMAINS` object, injected at
+ * deploy time by `run-wrangler-deploy`.
+ *
+ * It is keyed by the DEFAULT subdomain above, not by the service label, because the deploy
+ * script reads the very same object keyed by a worker's directory name — and every worker's
+ * directory name is its default subdomain. So one `.env` entry moves both sides at once:
+ * `{"playersettings":"settings"}` both deploys the `playersettings` worker onto
+ * `settings.<domain>` and advertises that host to the client. Entries naming a service with
+ * no worker of its own are pure client-side redirects — `{"moderation":"api"}` points the
+ * client's Moderation calls at the `api` worker, which is where the
+ * `/api/PlayerReporting/…` routes actually live.
+ *
+ * A malformed value is ignored rather than thrown: this document is the first thing the
+ * client fetches, so a typo in `.env` should cost one redirect, not every service host.
+ */
+function parseOverrides(subdomains: string | undefined): Record<string, string> {
+	if (!subdomains) return {}
+	let parsed: unknown
+	try {
+		parsed = JSON.parse(subdomains)
+	} catch {
+		return {}
+	}
+	if (typeof parsed !== 'object' || parsed === null || Array.isArray(parsed)) return {}
 	return Object.fromEntries(
-		Object.entries(SERVICE_SUBDOMAINS).map(([label, sub]) => [label, `https://${sub}.${domain}`])
+		Object.entries(parsed).filter(
+			(entry): entry is [string, string] => typeof entry[1] === 'string' && entry[1] !== ''
+		)
+	)
+}
+
+/**
+ * Builds the endpoints document for `domain`, e.g. `rec.example.com`, applying any
+ * subdomain overrides from `subdomains` (the raw `SUBDOMAINS` var JSON).
+ */
+export function buildEndpoints(domain: string, subdomains?: string): Record<string, string> {
+	const overrides = parseOverrides(subdomains)
+	return Object.fromEntries(
+		Object.entries(SERVICE_SUBDOMAINS).map(([label, sub]) => [
+			label,
+			`https://${overrides[sub] ?? sub}.${domain}`,
+		])
 	)
 }

apps/ns/src/ns.app.ts

@@ -29,6 +29,6 @@ const app = new Hono<App>()
 	.notFound(withNotFound())
 
 	// Endpoints document, derived from the deploy-time base domain.
-	.get('/', (c) => c.json(buildEndpoints(c.env.DOMAIN)))
+	.get('/', (c) => c.json(buildEndpoints(c.env.DOMAIN, c.env.SUBDOMAINS)))
 
 export default app

apps/ns/src/test/integration/api.test.ts

@@ -18,6 +18,19 @@ describe('ns endpoints', () => {
 		expect(body).toEqual(buildEndpoints(TEST_DOMAIN))
 	})
 
+	test('a subdomain override redirects that service only', () => {
+		const endpoints = buildEndpoints(TEST_DOMAIN, '{"moderation":"api"}')
+		expect(endpoints.Moderation).toBe(`https://api.${TEST_DOMAIN}`)
+		expect(endpoints.API).toBe(`https://api.${TEST_DOMAIN}`)
+		expect(endpoints.Accounts).toBe(`https://accounts.${TEST_DOMAIN}`)
+	})
+
+	test('a malformed override object is ignored', () => {
+		for (const bad of ['', '{', 'null', '[]', '{"moderation":42}', '{"moderation":""}']) {
+			expect(buildEndpoints(TEST_DOMAIN, bad)).toEqual(buildEndpoints(TEST_DOMAIN))
+		}
+	})
+
 	test('unknown path returns 404', async () => {
 		const res = await exports.default.fetch(`${ORIGIN}/nope`)
 		expect(res.status).toBe(404)

apps/ns/wrangler.jsonc

@@ -15,6 +15,7 @@
 	"vars": {
 		"ENVIRONMENT": "development", // overridden during deployment
 		"SENTRY_RELEASE": "unknown", // overridden during deployment
-		"DOMAIN": "rec.example.com" // base domain; overridden during deployment
+		"DOMAIN": "rec.example.com", // base domain; overridden during deployment
+		"SUBDOMAINS": "{}" // per-service subdomain overrides; overridden during deployment
 	}
 }