On the bundled sample Dockerfile: 3 findings (2 errors, 1 warning) from 21 rules - node:20 and Debian 11 bullseye on line 2, python:3.10 (end-of-life 31 October 2026) on line 10.

Who it’s for
For platform, DevOps and backend teams who own Dockerfiles, compose files and CI images and answer to a security audit.

What breaks, and when
Node.js 20 reached end-of-life on 30 April 2026 and Debian 11 bullseye LTS ended on 31 August 2026; postgres:14 and .NET 8 follow in November 2026.

What you get
• SKILL.md, an offline Node scanner and the 21-rule table
• file:line, end-of-life date and the replacement FROM line

See it first
The real output of the bundled example is on getreadystack.com/skills/dockerfile-base-image-eol-check/ — free, no sign-up, so you see what it finds before you pay.

Install in 30 seconds
Unzip into ~/.claude/skills/, then ask Claude Code: “We have a security audit coming up. Are any of the base images in our Dockerfiles or compose files end of life, and what should we move to? Don’t edit anything yet.”. Needs Node 16+.

What it does not do
It does not pull images or scan layers for CVEs; it reads text on disk only.

FAQ
Q: How is this different from asking Claude without the skill?
A: The skill carries a dated rule table and a scanner that reads every file, so Claude quotes the exact date and line instead of guessing from memory.
Q: How do I get the files?
A: In your Whop library after paying: the lesson “dockerfile-base-image-eol-check.zip”.