Add extractor listing api endpoint

Author: nbr23

ydl_server/ydlhandler.py

@@ -199,3 +199,6 @@ def get_ydl_website():
 
 def get_ydl_version():
     return ydl_module.version.__version__
+
+def get_ydl_extractors():
+    return [ie.IE_NAME for ie in ydl_module.extractor.list_extractors(app_config['ydl_options'].get('age-limit')) if ie._WORKING]

youtube-dl-server.py

@@ -65,6 +65,10 @@ def api_serve_finished_file(filename):
 def server_static(filename):
     return static_file(filename, root='./ydl_server/static')
 
+@app.route('/api/extractors')
+def api_list_extractors():
+    return json.dumps(ydlhandler.get_ydl_extractors())
+
 @app.route('/api/downloads/stats', method='GET')
 def api_queue_size():
     db = JobsDB(readonly=True)