relvacode/flask-microservice repository overview

⁠Python Flask Microservice

⁠Python Versions

This image comes in two varieties depending on what Python version you require.

• 2.7, 2, latest
• 3.6, 3

⁠Rapid Development

docker run -d -v /path/to/project:/app -p 80:80 relvacode/flask-microservice

All dependencies will be installed on start-up and uWSGI will automatically reload the Python application after a change is detected (20 second interval).

⁠ONBUIILD

Use this in your Dockerfile:

FROM relvacode/flask-microservice

When your image is built it will add the build context to /app and install any apt and pip dependencies during build time. This is the recommended method for production deployments.

⁠Stack Overview

• Ubuntu 18.04
• Python
• NGINX
  • Proxy the Python application on /api
  • Serve static files from /app/static
• uWSGI

  • Serves Python application in /app/app/api.py

⁠Default Packages

⁠Python Packages

• flask
• flask-restful
• uwsgi

⁠Ubuntu Packages

• nginx
• python-pip
• python-setuptools

⁠Application Folder Structure

The home directory where applications are served is /app. Under this directory your application should have this folder structure

• /app
  • app/ - This is where your Python code goes
    • api.py - Your main flask application file
  • static/ - Your static content such as .html, .js, .css files
  • requirements.apt - apt requirements, separated by newline
  • requirements.pip - pip requirements, separated by newline

⁠Environment Variables

⁠UWSGI_ENTRYPOINT

This sets what Python file/module in /app/app to serve using uWSGI. Do not include the file extension. Defaults to api which equates to /app/app/api.py

⁠UWSGI_APPLICATION

This sets what variable inside UWSGI_ENTRYPOINT points to the the uWSGI (Flask) application. Defaults to app.

⁠UWSGI_CHDIR

Change to this directory before loading the Python application. Defaults to /app/app.

⁠Flask

To enable error logging of application errors to the container log you should add the PROPAGATE_EXCEPTIONS parameter to the Flask configuration.

from flask import Flask
app = Flask(__name__)
app.config['PROPAGATE_EXCEPTIONS'] = True