Bluemix と Heroku の Flask で、Gmail の oauth 2.0 を使う

関連ページ　次のページのコードを使っています。
Flask 関連
Bluemix で、Node-RED で作成した API を、Flask から呼び出す

• static/index.html
• static/mail.js

Gmail oauth 2.0 関連
Python で、Gmail の oauth 2.0 を使う

• get_credentials.py
• client_secret.json
• .credentials/my-gmail-sender.json

フォルダー構成

Heroku では manifest.yml は不要です。

├── client_secret.json
├── get_credentials.py
├── Procfile
├── requirements.txt
├── runtime.txt
├── send_gmail_oauth2.py
├── static
│   ├── index.html
│   ├── lib
│   │   └── jquery-3.3.1.min.js
│   └── mail.js
├── welcome.py
├── manifest.yml
└── .credentials/my-gmail-sender.json

welcome.py

# -*- coding: utf-8 -*-
#
#   welcome.py
#
#                       Aug/30/2017
#
# ----------------------------------------------------------------------
import sys
import os

from flask import Flask
from flask import jsonify
from flask import request
app = Flask(__name__)

from send_gmail_oauth2 import send_gmail_proc
# ----------------------------------------------------------------------
@app.route("/")
def welcome():
    print("welcome")
    return app.send_static_file('index.html')
# ----------------------------------------------------------------------
@app.route('/post_mail' ,methods=['POST'])
def mail_proc():
    print("*** post_mail *** start ***")
    message = []
    message.append("*** mail *** start ***")
    message.append("request.method = " + request.method)
#
    to = request.form['to']
    topic = request.form['topic']
    content = request.form['content']
#
    try:
        send_gmail_proc(to,topic,content)
    except Exception as ee:
        sys.stderr.write("*** error *** send_gmail_proc ***\n")
        message.append("*** error *** send_gmail_proc ***")
        sys.stderr.write(str(ee) + "\n")
        message.append(str(ee))
#
    message.append("*** mail *** end ***")
    print("*** mail *** end ***")
#
    rvalue={}
    rvalue['to'] = to
    rvalue['content'] = content
    rvalue['message'] = message
#
    return jsonify(rvalue)
# ----------------------------------------------------------------------
port = os.getenv('PORT', '5000')
if __name__ == '__main__':
    app.debug = True
    app.run(host='0.0.0.0',  port=int(port))
# ----------------------------------------------------------------------

send_gmail_oauth2.py

# -*- coding: utf-8 -*-
#
#   send_gmail_oauth2.py
#
#                   Aug/30/2017
# ------------------------------------------------------------------
import httplib2
import os
import sys
import apiclient
import base64
import traceback
from email.mime.text import MIMEText
from email.utils import formatdate

from get_credentials import get_credentials
# ------------------------------------------------------------------
def send_gmail_proc(to,topic,content):
#
    credentials = get_credentials()
    http = credentials.authorize(httplib2.Http())
    service = apiclient.discovery.build("gmail", "v1", http=http)

    mail_from = "[e-mail]"

    try:
        result = service.users().messages().send(
            userId=mail_from,
            body=create_message(mail_from,to,topic,content)
        ).execute()

        print("Message Id: {}".format(result["id"]))

    except apiclient.errors.HttpError:
        print("------start trace------")
        traceback.print_exc()
        print("------end trace------")
#
# ------------------------------------------------------------------
def create_message(mail_from,mail_to,subject,contents):
    message = MIMEText(contents)
#
    message["from"] = mail_from
    message["to"] = mail_to
    message["subject"] = subject
    message["Date"] = formatdate(localtime=True)

    byte_msg = message.as_string().encode(encoding="UTF-8")
    byte_msg_b64encoded = base64.urlsafe_b64encode(byte_msg)
    str_msg_b64encoded = byte_msg_b64encoded.decode(encoding="UTF-8")

    body = {"raw": str_msg_b64encoded}
#
    return body
#
# ------------------------------------------------------------------

requirements.txt

Flask==1.0.2
requests==2.20.1
httplib2==0.12.0
oauth2client==4.1.3
google-api-python-client==1.7.4

runtime.txt

python-3.7.1

Procfile

web: python welcome.py