app.py

import os
import sys

from flask import Flask, request
from werkzeug.middleware.proxy_fix import ProxyFix

from linebot import (
    LineBotApi, WebhookHandler
)
from linebot.exceptions import (
    LineBotApiError, InvalidSignatureError
)

import logging

app = Flask(__name__)
#app.wsgi_app = ProxyFix(app.wsgi_app, x_for=1, x_host=1, x_proto=1)

# get channel_secret and channel_access_token from your environment variable
channel_secret = os.getenv('LINE_CHANNEL_SECRET', None)
channel_access_token = os.getenv('LINE_CHANNEL_ACCESS_TOKEN', None)
if channel_secret is None:
    print('Specify LINE_CHANNEL_SECRET as environment variable.')
    sys.exit(1)
if channel_access_token is None:
    print('Specify LINE_CHANNEL_ACCESS_TOKEN as environment variable.')
    sys.exit(1)

line_bot_api = LineBotApi(channel_access_token)
handler = WebhookHandler(channel_secret)


@app.route("/callback", methods=['POST'])
def callback():
    # get X-Line-Signature header value
    signature = request.headers['X-Line-Signature']

    # get request body as text
    body = request.get_data(as_text=True)
    app.logger.info("Request body: " + body)
    app.logger.info("X-Line-Signature: " + signature)

    # handle webhook body
    try:
        handler.handle(body, signature)
    except LineBotApiError as e:
        print("Got exception from LINE Messaging API: %s\n" % e.message)
        for m in e.error.details:
            print("  %s: %s" % (m.property, m.message))
        print("\n")
    except InvalidSignatureError:
        abort(400)

    return 'OK'

if __name__ != '__main__':
    gunicorn_logger = logging.getLogger('gunicorn.error')
    app.logger.handlers = gunicorn_logger.handlers
    app.logger.setLevel(gunicorn_logger.level)

if __name__ == '__main__':
    app.run(debug=True)