This tutorial covers simple steps to build and deploy a Flask application using Docker on Ubuntu 18.04. The sample application process data stored in a JSON file format and displayed on the browser.

Introduction

Docker is an open-source platform to develop, manage, and deploy applications using containers. For Docker installation, refer to this article.

Flask is a web micro-framework built on Python. 

Instructions

Step 1: Create a Dockerfile.

Dockerfile is a first step to containerize an application. Dockerfile contains a list of commands to assemble an image.

Step 2: Create a configuration file to install Flask framework of version 0.10.1

file name: requirements.txt

Step 3: Create a sample JSON data file.

file name: file.json 

Step 4: Write Python code to process JSON file data and flush out output to index.html. 

file name: app.py

Step 5: Index.html file render and display extract on the browser.

file name: Index.html 

Step 1 through 5 setup code and configuration of a Flask application on docker. Now execute the below-mentioned docker command to install and run the sample application.

$docker build -t flask_json:latest

log

$docker run -p 5000:5000 flask_json

log

Conclusion

These basic steps can get you started with the initial setup of a Flask application. This application can further scale to store data into a persistent source and furthermore.