Overview

We have summarized the procedure for creating a LineBot on AWS Lambda. I wrote from 1 without using line-bot-sdk-python. I use almost "reference" articles.

What is a webhook

-What is Webhook? -[What is a webhook? I tried to draw it so that even children can understand it](https://kintone-blog.cybozu.co.jp/developer/000283.html#:~:text=Webhook%E3%81%A8%E3%81%AF% EF% BC% 88% E7% 95% A5% EF% BC% 89% E3% 80% 81,% E3% 81% A7% E9% 80% 9A% E7% 9F% A5% E3% 81% 99% E3 % 82% 8B% E4% BB% 95% E7% B5% 84% E3% 81% BF% E3% 81% A7% E3% 81% 99% E3% 80% 82)

Development procedure introduction

Technology

Python
AWS Lambda

flow

Creating a Lambda function
Line Developer registration
Create Echolalia Bot
Let's play with the bot a little

The entire

import json  
import logging  
import os  
import urllib.request  

#Preparing for log output
logger = logging.getLogger()  
logger.setLevel(logging.INFO)  

def lambda_handler(event, context):  
    #Log output of request contents
    logger.info(event)  

    body = json.loads(event['body'])  

    for event in body['events']:  
        #Define a list of message objects for response
        messages = []  
        # 2.Webhook event type is message
        if event['type'] == 'message':  
            # 3.If the message type is text
            if event['message']['type'] == 'text':  
                # 4.Use the content of the received text as a message object
                if event['message']['text'] == 'honto':
                    messages.append({  
                            'type': 'image',  
                            'originalContentUrl': 'https://www.bizcourt.space/bizmarket/assets_c/2019/06/a_ocean_eyes_logo_bg_white_02-thumb-autox227-1304.png',
                            'previewImageUrl': 'https://www.bizcourt.space/bizmarket/assets_c/2019/06/a_ocean_eyes_logo_bg_white_02-thumb-autox227-1304.png'
                            })
                else:
                    messages.append({  
                          'type': 'text',  
                          'text': event['message']['text']+ 'is' 
                        })  

                #Define request information for response messages
                url = 'https://api.line.me/v2/bot/message/reply'  
                headers = {  
                    'Content-Type': 'application/json',  
                    #Get a LINE channel access token from an environment variable
                    'Authorization': 'Bearer ' + os.environ['LINE_CHANNEL_ACCESS_TOKEN']  
                    }  
                data = {  
                    #Set response token and message object
                    'replyToken': event['replyToken'],  
                    'messages': messages  
                }  
                request = urllib.request.Request(url, data = json.dumps(data).encode('utf-8'), method = 'POST', headers = headers)  
                with urllib.request.urlopen(request) as response:  
                    #Log output of response contents
                    logger.info(response.read().decode("utf-8"))  
    return {  
        'statusCode': 200,  
        'body': json.dumps('Hello from Lambda!')  
    }

Details

1. Creating a Lambda function

Python AWS Lambda Function Handler

2. Line Developer registration

Official documentation

3. Create Echolalia Bot

Throw a Post request

Use the urllib.request library. Official documentation Sample usage ... urllib.request is sufficient for Python HTTP client

Registration of environment variables From Using AWS Lambda Environment Variables

import os
region = os.environ['AWS_REGION']

You can use environment variables with.

4. Let's play with the bot a little

・ Return the image Image object of official document Refer to this document

messages.append({  
                            'type': 'image',  
                            'originalContentUrl': 'Image URL',
                            'previewImageUrl': 'Image URL'
                            })

Then you can return the image.

Reference: [How to send an image from a LINE bot] I made a LINE bot that returns an image of a Shiba Inu when asked

reference

LINE Messaging API x AWS Lambda simple response system # 1: Connect LINE to Lambda ← This service seems to be broken and the link is broken.

Impressions ・ Future ...

――Lambda is convenient. ――I want to improve my reading comprehension! ――LineBot seems to be applicable in more ways, so I'd like to do my best from now on.

Procedure for creating a Line Bot on AWS Lambda