config-loader: use multiple config roots

packages/config-loader/src/lib/resolver.ts

@@ -15,10 +15,11 @@
  */
 
 import { resolve as resolvePath } from 'path';
+import { pathExists } from 'fs-extra';
 
 type ResolveOptions = {
-  // Root path for search for app-config.yaml
-  rootPath: string;
+  // Root paths to search for config files. Config from earlier paths has higher priority.
+  rootPaths: string[];
 };
 
 /**
@@ -29,7 +30,14 @@ export async function resolveStaticConfig(
 ): Promise<string[]> {
   // TODO: We'll want this to be a bit more elaborate, probably adding configs for
   //       specific env, and maybe local config for plugins.
-  const configPath = resolvePath(options.rootPath, 'app-config.yaml');
+  const resolvedPaths = [];
 
-  return [configPath];
+  for (const rootPath of options.rootPaths) {
+    const path = resolvePath(rootPath, 'app-config.yaml');
+    if (await pathExists(path)) {
+      resolvedPaths.push(path);
+    }
+  }
+
+  return resolvedPaths;
 }

packages/config-loader/src/loader.ts

@@ -25,8 +25,8 @@ import {
 } from './lib';
 
 export type LoadConfigOptions = {
-  // Root path for search for app-config.yaml
-  rootPath: string;
+  // Root paths to search for config files. Config from earlier paths has higher priority.
+  rootPaths: string[];
 
   // Whether to read secrets or omit them, defaults to false.
   shouldReadSecrets?: boolean;