[match] tachyon sandbox switch

apps/match/src/match.app.ts

@@ -191,12 +191,12 @@ interface TachyonServer {
  * never sends the id anywhere), but it is positional, so inserting an entry renames
  * every server after it.
  */
-function tachyonPool(env: Env): TachyonServer[] {
-	return varOr(env.TACHYON_HOST_PORT, '')
+function tachyonPool(hostPorts: string, idPrefix = 'tachyon-'): TachyonServer[] {
+	return hostPorts
 		.split(',')
 		.map((entry) => entry.trim())
 		.filter((entry) => entry !== '')
-		.map((hostPort, i) => ({ hostPort, serverId: `tachyon-${i + 1}` }))
+		.map((hostPort, i) => ({ hostPort, serverId: `${idPrefix}${i + 1}` }))
 }
 
 /** What the connection info carries when there is no Tachyon server to name. */
@@ -223,44 +223,31 @@ const NO_TACHYON_SERVER: TachyonServer = { hostPort: '', serverId: '' }
  * `roomInstanceId` 0 means the caller resolved to no instance at all (they're in no
  * room, or named one that doesn't exist); they get no server rather than server one.
  */
-function tachyonServerFor(env: Env, roomInstanceId: number): TachyonServer {
-	const pool = tachyonPool(env)
+function tachyonServerFor(pool: TachyonServer[], roomInstanceId: number): TachyonServer {
 	if (pool.length === 0 || roomInstanceId <= 0) return NO_TACHYON_SERVER
 	return pool[roomInstanceId % pool.length] ?? NO_TACHYON_SERVER
 }
 
 /**
- * The Tachyon port a DEVELOPER is handed, in place of the port on the pool entry their
- * instance resolved to. Developers connect to a separate Tachyon build running beside the
- * live one on the same box, so only the PORT moves: the HOST stays whichever one
- * {@link tachyonServerFor} picked, rather than scattering developers off the pool.
+ * The prefix of a sandbox server's generated id (see {@link tachyonPoolFor}) — `dev-1`,
+ * `dev-2` rather than the live pool's `tachyon-N`, so the (cosmetic) id the client
+ * displays says which pool it is on.
  */
-const DEVELOPER_TACHYON_PORT = '7778'
+const SANDBOX_TACHYON_SERVER_ID_PREFIX = 'dev-'
 
 /**
- * The id displayed for that dev server. Not `tachyon-N` — the generated ids are positional
- * names for entries in the pool ({@link tachyonPool}), and the dev build is not one of
- * them: it is a different server that happens to share a host. The id is cosmetic (the
- * client displays it and never sends it anywhere), so it only has to say which server the
- * player is on, and "dev" is that.
+ * The pool the caller's instance is picked out of. A SANDBOX account runs against its own
+ * Tachyon servers, apart from the live pool, so the whole list is swapped for
+ * `TACHYON_HOST_PORT_SANDBOX` rather than any one entry: selection within it is the same
+ * instance-id round-robin {@link tachyonServerFor} applies to the live pool. When that var
+ * is unset a sandbox account falls back to the live pool, so an operator who runs no
+ * sandbox servers doesn't leave those accounts without voice.
  */
-const DEVELOPER_TACHYON_SERVER_ID = 'dev'
-
-/**
- * `server` with its port replaced by {@link DEVELOPER_TACHYON_PORT} and its id by
- * {@link DEVELOPER_TACHYON_SERVER_ID}. An empty address is left alone — the pool is unset or
- * the caller is in no instance, so there is no server to point at another port, and writing
- * a bare `:7778` would hand the client an address that answers nothing (and name a server
- * that isn't there). Splits on the LAST colon so a bracketed IPv6 host survives.
- */
-function developerTachyonServer(server: TachyonServer): TachyonServer {
-	if (server.hostPort === '') return server
-	const colon = server.hostPort.lastIndexOf(':')
-	const host = colon === -1 ? server.hostPort : server.hostPort.slice(0, colon)
-	return {
-		hostPort: `${host}:${DEVELOPER_TACHYON_PORT}`,
-		serverId: DEVELOPER_TACHYON_SERVER_ID,
-	}
+function tachyonPoolFor(env: Env, isSandbox: boolean): TachyonServer[] {
+	const sandbox = varOr(env.TACHYON_HOST_PORT_SANDBOX, '')
+	return isSandbox && sandbox.trim() !== ''
+		? tachyonPool(sandbox, SANDBOX_TACHYON_SERVER_ID_PREFIX)
+		: tachyonPool(varOr(env.TACHYON_HOST_PORT, ''))
 }
 
 /**
@@ -2907,8 +2894,8 @@ const app = new Hono<App>()
 				'`TACHYON_HOST_PORT` pool, chosen by instance id so every player in a session is',
 				'handed the same one, with a generated `voiceServerId` (`tachyon-1`, `tachyon-2`,',
 				'…). Both are empty when the pool is unset or the caller is in no instance. A',
-				'caller holding the DEVELOPER role gets that same host on port 7778, the dev',
-				'Tachyon build, with a `voiceServerId` of `dev`.',
+				'sandbox account is picked out of the `TACHYON_HOST_PORT_SANDBOX` pool instead, the same way,',
+				'with ids `dev-1`, `dev-2`, ….',
 				'`experiments` carries the client’s networking flags.',
 			].join(' '),
 			security: AUTHED,
@@ -2949,11 +2936,11 @@ const app = new Hono<App>()
 			}
 			const account = await getAccount(c.env.DB, id)
 			// The instance's server, the same one every other player in it is handed — except
-			// for a DEVELOPER, who is sent to the same host on the dev port, under the id
-			// `dev` rather than the pool entry's positional name.
-			const assigned = tachyonServerFor(c.env, roomInstanceId)
-			const tachyon =
-				account?.isDeveloper === true ? developerTachyonServer(assigned) : assigned
+			// that a SANDBOX account is picked out of the sandbox pool instead of the live one.
+			const tachyon = tachyonServerFor(
+				tachyonPoolFor(c.env, account?.isSandbox === true),
+				roomInstanceId
+			)
 
 			// Identifies the player to Photon. Signed with the shared JWT secret; the token's
 			// `aud` is the realtime app it's for. Nothing verifies it while Photon is
@@ -2977,8 +2964,8 @@ const app = new Hono<App>()
 					photonRoomId,
 					// The Tachyon server this instance runs on, picked out of the operator's
 					// pool by {@link tachyonServerFor} — empty strings when the pool is empty
-					// or the caller is in no instance, and on the dev port (id `dev`) for a
-					// developer. Empty rather than null: the client's
+					// or the caller is in no instance, and out of the sandbox pool for a
+					// sandbox account. Empty rather than null: the client's
 					// decoder is likelier to accept a missing-value string than a null on a
 					// string field. The presence payload's NULL_CONNECTION_INFO keeps its
 					// nulls — that one never carries credentials.