This document discusses building a LINE chatbot using a serverless architecture on AWS Lambda and the Python framework Chalice. It introduces the LINE Messaging API and LINE Bot SDK for Python. It then shows how to create a basic echo bot application that handles text messages in under 40 lines of Python code deployed to AWS Lambda using Chalice. The bot simply replies to users with their message text.

1. 40行で書ける！
Serverless LINE BOT
LINE Corporation
Tasuku OKUDA

2. Introduction
• Hadoop administrator/developer
• LINEスタンプ: https://store.line.me/stickershop/product/1464176
• Python @ LINE
• メッセージ流量やスタンプ販売数などの統計Batch
• 複雑なJob dependencyの管理
• セキュリティ監査やSpanモニタリングツールの開発
• LINE Messaging API SDK

3. LINE Messaging API

4. LINE Messaging API
• https://business.line.me/ja/services/bot
• Doc: https://devdocs.line.me/ja/
• LINEサーバ経由で、ユーザ側のLINE
appと開発者側のシステムを繋ぐAPI
• JSON Webhook
• Imagemap、Carouselなど、Messaging
APIならではのメッセージも

5. LINE Bot SDK for Python
• Github: https://github.com/line/line-
bot-sdk-python
• PyPi: https://pypi.python.org/pypi/line-
bot-sdk/1.3.0
• Messaging APIの様々なRequest/
ResponseをPython objectで扱えるSDK
• WebhookHandlerでEvent/MessageType
毎の処理を分離して書ける

6. LINE Messaging API
+
Serverless

7. Serverless LINE BOT
LINE app
(User)
LINE
Messaging API Server
AWS
API Gateway
AWS
Lambda
Event
Webhook
POST req
POST request
to Messaging API
Response
chalice
Python Serverless Microframework

9. $ pip install line-bot-sdk chalice
$ chalice new-project line-bot
https://gist.github.com/okdtsk/af70f33e2197b759848df8d6a800ce0a

10. from chalice import Chalice
app = Chalice(app_name=‘line-bot’)
from linebot import LineBotApi
from linebot import WebhookHandler
line_bot_api = LineBotApi(os.environ['LINEBOT_ACCESS_TOKEN'])
handler = WebhookHandler(os.environ['LINEBOT_SECRET'])
https://gist.github.com/okdtsk/af70f33e2197b759848df8d6a800ce0a

11. @app.route('/callback', methods=['POST'])
def callback():
signature = app.current_request.headers['X-Line-Signature']
body = app.current_request.raw_body.decode('utf-8')
try:
handler.handle(body, signature)
except InvalidSignatureError as e:
return Response({‘error': e.message}, status_code=400)
return Response({'ok': True})
https://gist.github.com/okdtsk/af70f33e2197b759848df8d6a800ce0a

12. @handler.add(MessageEvent, message=TextMessage)
def handle_text_message(event):
line_bot_api.reply_message(
event.reply_token,
TextSendMessage(text=‘Reply: {}’.format(event.message.text))
)
https://gist.github.com/okdtsk/af70f33e2197b759848df8d6a800ce0a

13. $ chalice deploy
https://gist.github.com/okdtsk/af70f33e2197b759848df8d6a800ce0a

15. 40行でecho bot！
https://gist.github.com/okdtsk/af70f33e2197b759848df8d6a800ce0a

16. LINE BOTはかんたん！
作
っ
て
み
て
ね

17. Thank you!