Lab: the helpful fetcher
An image proxy fetches any URL. Tour the inside of its network.
Read the fetcher and confirm it takes arbitrary URLs. Fetch something public first for the baseline, then turn it inward: loopback, then the cloud metadata address. The bytes that come back decide the severity — read them carefully.
That was the whole lesson.
A free account adds the interactive part: the marking quiz, the lab if this lesson carries one, live progress, the timed exam, and a certificate employers can verify.