Lambda functon to generate Box Note regularly

regular_boxnotes.py

# -*- coding: utf-8 -*-
# See also http://blog.serverworks.co.jp/tech/2016/06/02/minutes-automation/

import json
import boto3
import urllib2
import httplib
from base64 import b64encode, b64decode
from datetime import datetime, timedelta

client = boto3.client('dynamodb')
table_name = 'box_api'
app_id = 0

key_id = 'arn:aws:kms:ap-northeast-1:[AWS_account_ID_without_hyphen]:key/[KMS_Key_ID]'

original_file_id = '[Original_File_ID]'
copy_destination = '[Copy_Destination_Folder_ID]'
filename_suffix = u'_技術2課_週次定例議事メモ.boxnote'

ENCRYPTED_HOOK_URL = '[Encrypted_Hook_URL]'
SLACK_CHANNEL = '#dept-tech02'
HOOK_URL = "https://" + boto3.client('kms').decrypt(CiphertextBlob=b64decode(ENCRYPTED_HOOK_URL))['Plaintext']

def kms_decrypt(encrypted_str):
  return boto3.client('kms').decrypt(CiphertextBlob=b64decode(encrypted_str))['Plaintext']

def kms_encrypt(decrypted_str):
  return b64encode(boto3.client('kms').encrypt(KeyId=key_id, Plaintext=decrypted_str)['CiphertextBlob'])

def get_item_from_db(table_name, app_id):
  item = client.get_item(
    TableName = table_name, 
	Key={
        'app_id': {'N': str(app_id)}
    }
  )['Item']
  return item

def refresh_request(refresh_token_old, client_id, client_secret):
  url = 'https://api.box.com/oauth2/token'
  data_str = 'grant_type=refresh_token&refresh_token=%s&client_id=%s&client_secret=%s' % (refresh_token_old, client_id, client_secret)
  header = {}

  request = urllib2.Request(url, data_str, header)
  return json.loads(urllib2.urlopen(request).read())

def update_db(access_token, refresh_token_new):
  encrypted_access_token = kms_encrypt(access_token)
  encrypted_refresh_token_new = kms_encrypt(refresh_token_new)
  
  client.update_item(
    TableName = table_name, 
	Key={
      'app_id': {'N': str(app_id)}
    }, 
	UpdateExpression="set access_token = :a, refresh_token = :r",
    ExpressionAttributeValues={
      ':a': {'S': encrypted_access_token}, 
      ':r': {'S': encrypted_refresh_token_new}
    }
  )

def copy_file(access_token, original_file_id, copy_destination, filename):
  url = 'https://api.box.com/2.0/files/' + original_file_id + '/copy'
  data = {'parent': {'id': copy_destination}, 'name': filename}
  header = {'Authorization': 'Bearer ' + access_token}

  request = urllib2.Request(url, json.dumps(data), header)
  reply = urllib2.urlopen(request)
  return json.loads(reply.read())

def create_shared_link(access_token, file_id):
  url = 'api.box.com'
  uri = '/2.0/files/' + file_id
  data = {"shared_link": {}}
  header = {'Authorization': 'Bearer ' + access_token}

  connection = httplib.HTTPSConnection(url)
  connection.request("PUT", uri, json.dumps(data), header)
  reply = connection.getresponse()
  return json.loads(reply.read())

def slack_post(HOOK_URL, SLACK_CHANNEL, file_info):
  file_name = file_info['name']
  link_url = file_info['shared_link']['url']

  slack_message = {
    'channel': SLACK_CHANNEL, 
    'text': u"来週の週次定例議事メモを作成しました。\nファイル名: %s\nリンク: %s" % (file_name, link_url), 
  }

  request = urllib2.Request(HOOK_URL, json.dumps(slack_message))
  urllib2.urlopen(request)

def lambda_handler(event, context):
  print('Getting Refresh Token etc from Database')
  item = get_item_from_db(table_name, app_id)

  print('Decrypting Refresh Token etc')
  refresh_token_old = kms_decrypt(item['refresh_token']['S'])
  client_id = kms_decrypt(item['client_id']['S'])
  client_secret = kms_decrypt(item['client_secret']['S'])

  print('Requesting New Refresh Token and Access Token')
  reply_for_refresh = refresh_request(refresh_token_old, client_id, client_secret)
  # print(reply_for_refresh)

  access_token = reply_for_refresh['access_token']
  refresh_token_new = reply_for_refresh['refresh_token']

  print('Updating Refresh Token')
  update_db(access_token, refresh_token_new)

  filename_prefix = (datetime.now() + timedelta(days=7)).strftime('%Y%m%d')
  filename = filename_prefix + filename_suffix
  print('Copying file as ' + filename)
  reply_from_copy_file = copy_file(access_token, original_file_id, copy_destination, filename)
  
  reply_from_create_shared_link = create_shared_link(access_token, reply_from_copy_file['id'])
  
  print('Posting on Slack')
  slack_post(HOOK_URL, SLACK_CHANNEL, reply_from_create_shared_link)

  print('Done')