add api keys singleton json wrapper

src/api/keys.ts

@@ -0,0 +1,31 @@
+import { openSync, readFileSync } from "fs";
+import { O_RDONLY } from "constants";
+import { join } from "path";
+
+export default class Key{
+
+	// Static
+	static _singleton?: Key;
+	static _config: any;
+	static get(key: string) : any{
+
+		if( Key._singleton == null )
+			Key._singleton = new Key();
+
+		return Key._config[key] || null;
+	}
+
+
+	// instance
+	private constructor(){
+		let path = join(__dirname, '../../cnf/api_keys.json')
+		let fd = openSync(path, O_RDONLY)
+
+		if( fd < 0 )
+			throw new Error(`cannot open file ${path}`)
+
+		Key._config = JSON.parse( readFileSync(fd).toString() )
+	}
+
+
+}