I made a LINE BOT with Python and Heroku

I made a LINE BOT that returns parrots as part of Python learning.

Complete image

Environmental configuration

・ Python ・ Heroku ・ LINE Developers ・ Flask

Development procedure

1. LINE Developers Registration & Settings
2. Heroku Registration & Settings
3. Implemented in Python
4. LINE Developers settings again
5. Deploy to Heroku

LINE Developers Registration & Settings

Create a LINE Developers account, provider, and channel at the link below. https://developers.line.biz/ja/services/messaging-api/

Account creation

You can create an account with your name and email address.

Provider creation

Created with the provider name (your name or company name)

Channel creation

・ Channel type → Messaging API ・ Provider ・ Channel name ・ Channel description ・ Category ・ Subcategory ·e-mail address Create by agreeing to the terms of use.

Register as a friend

Register as a friend with the QR code of the channel basic setting → message API.

Confirmation of required information

Basic settings → Check channel secret Message API settings → Channel access token issuance and confirmation

Heroku Registration & Settings

Heroku is simply a service that prepares you for publishing your application. What is Heroku

Heroku installation

For the installation settings etc., I referred to the following article. https://uepon.hatenadiary.com/entry/2018/07/27/002843

Heroku settings

Login with GitCMD

GitCMD

heroku login

heroku: Press any key to open up the browser to login or q to exit:
Opening browser to https://cli-auth.heroku.com/auth/browser/XXXX
Logging in... done
Logged in as XXXX@XXXX

Application registration

GitCMD

heroku create your application name(Below app name)

Creating ● App name... done
https://app name.herokuapp.com/ | https://git.heroku.com/app name.git

Setting environment variables → Reference: What are environment variables Set the channel secret and channel access token confirmed in LINE Developers earlier.

GitCMD

heroku config:set YOUR_CHANNEL_SECRET="Channel Secret string" --app app name
heroku config:set YOUR_CHANNEL_ACCESS_TOKEN="Access token string" --app app name

With this setting "YOUR_CHANNEL_SECRET" is a channel secret "YOUR_CHANNEL_ACCESS_TOKEN" is a channel access token Will be available on Heroku as.

Check settings

GitCMD

heroku config --app app name

Implemented in Python

Library installation

Enter the following contents in GitCMD.

GitCMD

pip3 install flask
pip3 install line-bot-sdk

-Flask is a Python web application framework suitable for creating simple web applications for small scale. → Reference: What is Flask

-Line-bot-sdk contains the functions required to create a LINE BOT. → Reference: What is line-bot-sdk

For the actual code, I referred to main.py on the following site. https://uepon.hatenadiary.com/entry/2018/07/27/002843 In addition, I referred to the following site to understand what is written. https://www.wantedly.com/companies/casley/post_articles/139107

main.py

#Loading required modules
from flask import Flask, request, abort
import os
from linebot import (
    LineBotApi, WebhookHandler
)
from linebot.exceptions import (
    InvalidSignatureError
)
from linebot.models import (
    MessageEvent, TextMessage, TextSendMessage,
)

#Assign Flask to the variable app. Instantiation
app = Flask(__name__)

#Get environment variables
YOUR_CHANNEL_ACCESS_TOKEN = os.environ["YOUR_CHANNEL_ACCESS_TOKEN"]
YOUR_CHANNEL_SECRET = os.environ["YOUR_CHANNEL_SECRET"]

line_bot_api = LineBotApi(YOUR_CHANNEL_ACCESS_TOKEN)
handler = WebhookHandler(YOUR_CHANNEL_SECRET)

#Method for Heroku login connection confirmation
#When I log in to Heroku, "hello world" is displayed in the browser
@app.route("/")
def hello_world():
    return "hello world!"

#When a message is sent by the user, this method is called from the LINE Message API.
@app.route("/callback", methods=['POST'])
def callback():
    #Get the value for signature verification from the request header
    signature = request.headers['X-Line-Signature']

    #Get request body
    body = request.get_data(as_text=True)
    app.logger.info("Request body: " + body)

    #Verify the signature, and if there is no problem, call the function defined in handle.
    try:
        handler.handle(body, signature)
    #If signature verification fails, throw an exception.
    except InvalidSignatureError:
        abort(400)
    #OK if you finish processing the handle
    return 'OK'

#When a Message Event (when a normal message is sent) occurs on LINE,
#def Execute the following function.
# reply_event, the first argument of message.reply_token is a token used to respond to an event.
#The second argument is linebot.We are passing the TextSendMessage object for the reply defined in models.
@handler.add(MessageEvent, message=TextMessage)
def handle_message(event):
    line_bot_api.reply_message(
        event.reply_token,
        TextSendMessage(text=event.message.text))

#Port number setting
if __name__ == "__main__":
#    app.run()
    port = int(os.getenv("PORT"))
    app.run(host="0.0.0.0", port=port)

Webhook settings

Go back to the LINE Message API and set the Heroku connection destination in the Webhook URL of the Webhook. Webhook URL: https: // app name.herokuapp.com/callback * Don't forget to enter the callback method at the end </ font>

python --version

pip freeze

Python 3.9.0

Flask==1.1.2
line-bot-sdk==1.17.0

cd linebot  
git init
git add .
git commit -am "make it better"
git push heroku master

heroku open

heroku logs --tail