initial commit

apps/api/src/modules/config/config-file-gateway.ts

@@ -0,0 +1,66 @@
+import { ApiError } from '../../lib/errors.js';
+import type { GameServerProvider } from '../pterodactyl/types.js';
+
+const CONFIG_MAX_BYTES = 256 * 1024;
+
+export function asRecord(value: unknown): Record<string, unknown> | null {
+  return typeof value === 'object' && value !== null && !Array.isArray(value)
+    ? (value as Record<string, unknown>)
+    : null;
+}
+
+/**
+ * Shared read-modify-write access to the server's config.json: size-guarded
+ * download + parse, and a write path that backs the previous content up to
+ * `<config>.bak` and verifies the upload by downloading it again. Callers
+ * mutate only their own keys on the parsed document so everything else in the
+ * file passes through untouched.
+ */
+export class ConfigFileGateway {
+  constructor(
+    private readonly provider: GameServerProvider,
+    readonly configPath: string,
+  ) {}
+
+  async download(
+    providerServerId: string,
+  ): Promise<{ raw: string; root: Record<string, unknown> }> {
+    const file = await this.provider.downloadTextFile(
+      providerServerId,
+      this.configPath,
+      CONFIG_MAX_BYTES,
+    );
+    if (file.truncated) {
+      throw ApiError.upstream('Server config.json is unexpectedly large; refusing to modify it.');
+    }
+    let parsed: unknown;
+    try {
+      parsed = JSON.parse(file.content.replace(/^\uFEFF/, ''));
+    } catch {
+      throw ApiError.upstream('Server config.json is not valid JSON.');
+    }
+    const root = asRecord(parsed);
+    if (!root || !asRecord(root.game)) {
+      throw ApiError.upstream('Server config.json has no "game" section; refusing to modify it.');
+    }
+    return { raw: file.content, root };
+  }
+
+  /**
+   * Backs up `previousRaw`, writes the mutated document, downloads it again
+   * and hands the verified parsed result to `verify` (throw there to fail).
+   */
+  async write(
+    providerServerId: string,
+    root: Record<string, unknown>,
+    previousRaw: string,
+    verify: (readBack: Record<string, unknown>) => void,
+  ): Promise<Record<string, unknown>> {
+    await this.provider.writeTextFile(providerServerId, `${this.configPath}.bak`, previousRaw);
+    const serialized = `${JSON.stringify(root, null, 4)}\n`;
+    await this.provider.writeTextFile(providerServerId, this.configPath, serialized);
+    const readBack = await this.download(providerServerId);
+    verify(readBack.root);
+    return readBack.root;
+  }
+}