Miguel Grinberg's Flask Mega-Tutorial 2024 edition

Implemented by José Agustín Moreno

We develop a microblogging site using Flask as shown in Miguel Grinberg's Mega-Tutorial

Requirements

We have installed so far:

• Python
• Flask
• python-dotenv
• Flask-WTF
• WTForms
• Flask-SQLAlchemy
• Flask-Migrate
• Flask-Login
• Flask-Moment
• email-validator
• langdetect
• requests
• elasticsearch

Installation

First, create a virtual environment in our main directory, and install the necessary packages:

$ python -m venv venv
$ source venv/bin/activate
$ [venv] pip install -r requirements.txt

Execution

Run flask run on the top-level directory

Elasticsearch

To install the Elasticsearch engine in Docker:

$ sudo docker network create elastic
$ sudo docker pull docker.elastic.co/elasticsearch/elasticsearch:9.1.4

To start the Elasticsearch engine with Docker, run

$ sudo docker run --name elasticsearch --network elastic \
--rm -p 9200:9200 --memory 2GB -e discovery.type=single-node \
-e xpack.security.enabled=false \
-t docker.elastic.co/elasticsearch/elasticsearch:9.1.4

Celery

We use Celery as our task queue. In addition to that, we need either a Redis or Valkey server up and running.

To get our Celery worker started, we need to

$ celery -A microblog.celery_app worker --loglevel INFO

on our root directory.

Deploying with Vagrant and Ubuntu Linux

To create the VM with the provided Vagrantfile:

$ vagrant up

We can start a SSH session with $ vagrant ssh and set up our environment.

Once inside the VM shell, we install the following packages:

$ sudo apt-get -y update
$ sudo apt-get -y install python3 python3-venv python3-dev
$ sudo apt-get -y install mysql-server postfix supervisor nginx git

Be sure to install Elasticsearch as you see fit, in my case I still used the Docker container. Use the files found in deployment to configure both supervisor and nginx.

Install as directed above, then add these additional packages.

[venv] $ pip install gunicorn pymysql cryptography

Configure the .env file

SECRET_KEY=52cb883e323b48d78a0a36e8e951ba4a
MAIL_SERVER=localhost
MAIL_PORT=25
DATABASE_URL=mysql+pymysql://microblog:<db-password>@localhost:3306/microblog
MS_TRANSLATOR_KEY=<your-translator-key-here>

We now compile the language translations

[venv] $ flask translate compile

To set up the MySQL server, supervisor and nginx, please refer to Miguel's tutorial

Next steps

I should figure out how to automate the app deployment, either to a Linux box or using a multi-container solution such as Docker Compose.