Docker Starter Python

This repo will get you up and running with a basic containerized Python app setup.

If you're here, you might not be familiar with a bunch of these concepts, or may have never run code via a container before. Containers solve the problem of "hm... well, it works on my computer...".

In a containerized project, in addition to any application/scripting code, you'll also declaratively define the steps to create the environment needed to develop/test/run your application. This:

• Allows others to easily get up and running on a project with minimal setup
• Avoids issues that arise from differences in environment setup (especially in Python, where the environment is by default global)
• Enables your application to easily be deployed (Kubernetes, VMs, Lambdas, etc.)

What do these files do?

.gitignore

This file is used to ignore different artifacts that Python projects usually create during their lifetime. This was copied from GitHub's default .gitignore files, which can be found here.

Dockerfile

This file declaritively details the steps to reproduce the environment for this application. We start with a Python base image (link) and list the additional steps to install our application's required packages and copy the actual application code into the container's /opt/app directory. This is also the working directory when we run make shell and enter the container in interactive mode.

Makefile

While these are typically used for more advanced compilation and deployment tasks, using a Makefile simplifies the Docker build and run steps. We don't have to memorize different options/flags - we just have easy targets (build and run) which abstract that from us.

README.md

This file!

requirements.txt

You might be familiar with this type of file, but you might also be used to installing packages à la carte via pip install <package>. Using a requirements.txt allows us to specify all the Python packages and versions that our application will need to run.

Prerequisites

You must have Docker installed on your machine to run docker commands. Docker makes versions for Linux, Mac, and Windows. They're available here.

Steps

1. Clone this repo and rename it per your project
2. Add your code
3. Edit the Makefile and requirements.txt files as necessary

Then:

• To build an image of this app, run make build
• To launch an interative shell inside the container, run make shell
• To run the app in the foreground, run make run