fix(config)!: validate and derive config, drop the unread keys (#2482)

fluxer_api/src/api/openapi/OpenAPIController.ts

@@ -2,18 +2,29 @@
 
 import * as fs from 'node:fs';
 import type {Hono} from 'hono';
+import {Config} from '../Config';
 import {RateLimitMiddleware} from '../middleware/RateLimitMiddleware';
 import {RateLimitConfigs} from '../RateLimitConfig';
 import type {HonoEnv} from '../types/HonoEnv';
 import {resolveAssetPath} from '../utils/AssetPaths';
 
 const SPEC_PATH = resolveAssetPath('openapi', 'openapi.json');
-const SPEC_BODY = fs.readFileSync(SPEC_PATH, 'utf-8');
+const SPEC_DOCUMENT = JSON.parse(fs.readFileSync(SPEC_PATH, 'utf-8')) as Record<string, unknown>;
+
+let specBody: string | null = null;
+
+export function buildOpenAPISpecBody(apiClientEndpoint: string): string {
+	return JSON.stringify({
+		...SPEC_DOCUMENT,
+		servers: [{url: `${apiClientEndpoint.trim().replace(/\/+$/u, '')}/v1`, description: 'This deployment'}],
+	});
+}
 
 export function OpenAPIController(app: Hono<HonoEnv>): void {
 	app.get('/openapi.json', RateLimitMiddleware(RateLimitConfigs.INSTANCE_INFO), (ctx) => {
+		specBody ??= buildOpenAPISpecBody(Config.endpoints.apiClient);
 		ctx.header('Access-Control-Allow-Origin', '*');
 		ctx.header('Content-Type', 'application/json; charset=utf-8');
-		return ctx.body(SPEC_BODY);
+		return ctx.body(specBody);
 	});
 }