bots: Add simple flask server for running contrib bots.

flask_bot_server.py

@@ -0,0 +1,70 @@
+from __future__ import absolute_import
+from flask import Flask, request, jsonify
+import os
+import sys
+import json
+from typing import Any, Dict, Mapping, Union, List
+from werkzeug.exceptions import BadRequest
+from six.moves.configparser import SafeConfigParser
+
+our_dir = os.path.dirname(os.path.abspath(__file__))
+
+# For dev setups, we can find the API in the repo itself.
+if os.path.exists(os.path.join(our_dir, '../api/zulip')):
+    sys.path.insert(0, '../api')
+
+from zulip import Client
+from bots_api.run import get_lib_module
+from bots_api.bot_lib import BotHandlerApi, StateHandler
+
+bots_config = {}  # type: Dict[str, Mapping[str, str]]
+available_bots = []  # type: List[str]
+bots_lib_module = {}  # type: Dict[str, Any]
+
+def read_config_file(config_file_path):
+    # type: (str) -> None
+    parser = SafeConfigParser()
+    parser.read(config_file_path)
+
+    for section in parser.sections():
+        bots_config[section] = {
+            "email": parser.get(section, 'email'),
+            "key": parser.get(section, 'key'),
+            "site": parser.get(section, 'site'),
+        }
+
+def load_lib_modules():
+    # type: () -> None
+    for bot in available_bots:
+        path = "bots/" + str(bot) + "/" + str(bot) + ".py"
+        bots_lib_module[bot] = get_lib_module(path)
+
+app = Flask(__name__)
+
+@app.route('/bots/<bot>', methods=['POST'])
+def handle_bot(bot):
+    # type: (str) -> Union[str, BadRequest]
+    if bot not in available_bots:
+        return BadRequest("requested bot service {} not supported".format(bot))
+
+    client = Client(email=bots_config[bot]["email"],
+                    api_key=bots_config[bot]["key"],
+                    site=bots_config[bot]["site"])
+    restricted_client = BotHandlerApi(client)
+    message_handler = bots_lib_module[bot].handler_class()
+
+    # TODO: Handle stateful bots properly.
+    state_handler = StateHandler()
+
+    event = json.loads(request.data)
+    message_handler.handle_message(message=event["message"],
+                                   client=restricted_client,
+                                   state_handler=state_handler)
+    return "Success!"
+
+if __name__ == "__main__":
+    read_config_file(sys.argv[1])
+    available_bots = list(bots_config.keys())
+    load_lib_modules()
+
+    app.run(host="127.0.0.1", port=5002, debug=True)