Lesson 1: Containers, one box that runs anywhere

Module 13 · Lesson 1 · About 40 minutes · Needs: Module 10, Lesson 1 (a FastAPI app)

The situation

Dev wants BrightCart's API on a staging server. On your laptop, GET /orders/5730 returns Aisha Rahman's QuietBoil kettle, shipped. On the server the same code fails: older Python, different FastAPI. Sam adds a worry: your .env file holds a provider key that must never leave your laptop.

The fix is to ship the API with everything it needs in one sealed box, a container. This lesson writes BrightCart's container files and checks each one in Python. Docker does not run in Colab, so docker commands are given exactly, marked "not run here", with the docs they were checked against.