Status Codes
Core Idea
HTTP status codes summarize what happened to a request.
Practice Alone
Run a header request and read the first line:
curl -I https://lf2607.kolamayermakers.org/~username/
Useful beginner set:
200: the request succeeded.301or302: the server redirects the client to another URL.404: the server is reachable, but that path is missing.500: the backend failed while handling the request.502: a proxy could not get a valid response from its backend.
For this course, 502 usually means Caddy received the public request but could not reach your user service.
Done When
You can explain whether failure is missing content, server error, or bad proxying.
Docs Pointers
- Read curl -I, HTTP inspection, and reverse proxy.

Linux Foundations