Flask-MySQL-Nginx-Starter

A starter kit for running backend service using Nginx, Flask, and MySQL as Docker containers.

Description

This is a simple starter kit for initializing Flask application to run inside Docker container accessing MySQL running inside a container. The Nginx server running inside a container acts as a reverse proxy.

Container Name	Description
backend	Container to run flask application
db	Container to run a MySQL 5.7 Database
nginx	Container to run Nginx Server as reverse proxy

The current docker-compose file sets up the development environment to work.
However, to run the container in production, uncomment the lines specified in respective files and remove backend/run.py.
The production environment uses gunicorn as a production WSGI HTTP server.

How to Use

Set up an instance directory in the project root folder and add a file config.py. This file is used to set configuration information for the Flask App instance.
An example instance/config.py looks like

import os

user = os.environ['MYSQL_USER']
password = ['MYSQL_PASSWORD']
host = os.environ['MYSQL_HOST']
database = ['MYSQL_DATABASE']

SECRET_KEY = '<Enter your secret Key>'
SQLALCHEMY_DATABASE_URI = f'mysql://{user}:{password}@{host}/{database}'

The .env file should also be set up to export the environment variables to the docker container through docker-compose.yml.

A sample .env file looks like

MYSQL_USER = dt_admin
MYSQL_PASSWORD = dt2016
MYSQL_HOST = localhost
MYSQL_DATABASE = dreamteam_db
MYSQL_ROOT_PASSWORD_FILE = /run/secrets/db-password

The /run/secrets/ is the location inside the docker container where the secrets are located.

Also, set up a /db/password.txt file to store the root password.

The /db/init.sql file consists of intialization code for the db container. All the database initialization steps (like creation of tables, giving permissions to users, etc.) can be run through this file.

Building and Starting the Containers

To start the containers, use

$ docker-compose up

To run in detached mode, use -d argument.

To stop the containers, use

$ docker-compose down

To remove the volumes also, use -v argument.
In case of interactive shell, use ctrl+c to gracefully close the running containers.

In case of any issues, delete the images corresponding to the container and restart everything using docker-compose up.

Accessing the Flask Application

The Flask application can be accessed through localhost from any web browser.