DummyApp/main.py

from flask import Flask

app = Flask(__name__)


@app.route('/')
def hello_world():  # put application's code here
    return 'Hello World!'


if __name__ == '__main__':
    # host='0.0.0.0' для доступа извне контейнера
    app.run(host='0.0.0.0', port=5000, debug=False)