Python3.7 Flask를 Google App Engine에 deploy하는 방법

$ mkdir flask-python37
$ cd flask-python37

runtime: python37

Flask==1.0.2

pip install  -r requirements.txt

from flask import Flask

app = Flask(__name__)

@app.route('/')
def hello():
  return "Hello"

if __name__ == '__main__':
    app.run(host='127.0.0.1', port=8088, debug=True)  

$ python main.py
 * Serving Flask app "main" (lazy loading)
 * Environment: production
   WARNING: Do not use the development server in a production environment.
   Use a production WSGI server instead.
 * Debug mode: on
 * Running on http://127.0.0.1:8088/ (Press CTRL+C to quit)
 * Restarting with stat
 * Debugger is active!
 * Debugger PIN: 289-847-358

$ gcloud app deploy
$ gcloud app browse

Beginning deployment of service [default]...
╔════════════════════════════════════════════════════════════╗
╠═ Uploading 0 files to Google Cloud Storage                ═╣
╚════════════════════════════════════════════════════════════╝
File upload done.
ERROR: (gcloud.app.deploy) INVALID_ARGUMENT: Please update to the latest version of gcloud. If you are using the API directly, please provide a value for version.entrypoint.shell. This can be an empty value.