Claude Code skills · updated 2026-10-03

Dockerfile EOL skill for Claude Code — end-of-life base images and FROM fixes

End-of-life base images in your Dockerfiles, with file:line, date and new FROM

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.

Get it on Whop - $12 onceGet it on Gumroad

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 it printed on the bundled example

== Dockerfile EOL Lint — 3 findings (2 errors, 1 warning) in 1 file · 21 rules
  ERROR Dockerfile:2  [rule-1]
        node:20 - Node.js 20 reached end-of-life on 30 April 2026. No security release has shipped for it since. Replace with node:24-trixie (Active LTS to 30 April 2028).
        fix: FROM node:24-trixie
  ERROR Dockerfile:2  [rule-6]
        Debian 11 bullseye LTS ended on 31 August 2026 - no security updates from September 2026 onward. Replace with debian:trixie, or bookworm if you need LTS to 30 June 2028.
        fix: FROM debian:trixie
  WARN  Dockerfile:10  [rule-5]
        python:3.10 - Python 3.10 reaches end-of-life on 31 October 2026. After that date the PSF ships no further security patches. Replace with python:3.13-trixie.

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
• Node, Python, Debian, Ubuntu, Alpine, .NET, Postgres, MySQL, PHP, CentOS
• CI: node scripts/scan.js . exits 1 on any error

Install

Unzip into ~/.claude/skills/ (all projects) or your-repo/.claude/skills/ (one repo), 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+.

unzip dockerfile-base-image-eol-check.zip -d ~/.claude/skills/

Ask Claude

“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.”

What it does not do

It does not pull images or scan layers for CVEs; it reads text on disk only. No network calls, no edits without your OK.

FAQ

What is a Claude Code skill?

A folder with a SKILL.md and scripts that Claude Code loads when your request matches it. You ask in plain words and Claude runs the scanner the skill carries.

How is this different from asking Claude without the skill?

The skill carries a dated rule table and a scanner that reads every file, so Claude quotes the exact date and line instead of answering from memory.

Does it send my code anywhere?

It does not pull images or scan layers for CVEs; it reads text on disk only. No network calls, no edits without your OK.

How do I install it?

Unzip into ~/.claude/skills/ (all projects) or your-repo/.claude/skills/ (one repo), 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 do I get when I buy?

The zip. On Whop it is in your library as a download lesson with the zip attached; on Gumroad it is the product file.