docker-hadolint

docker-hadolint is a skill for Claude Code from TheBeardedBearSAS/claude-craft. It costs 28 tokens per session (594 once invoked), scanned A, original, MIT.

A guide to Docker, a tool for packaging software and its dependencies into containers, and Hadolint, a checker for Dockerfiles. It includes validation and Dockerfile practices.

In plain words
What is it for?
Use it when writing or reviewing Dockerfiles, working with containers, or running Hadolint validation.
Why use it?
It helps catch Dockerfile problems and apply consistent container-building practices.

Skill for Claude Code

Written for Claude Code: context: fork in frontmatter.

Part of the claude-craft plugin — 56 skills, 94 commands, 47 agents, 5 hooks shipped together

Good fit Use it when writing or reviewing Dockerfiles, working with containers, or running Hadolint validation.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/thebeardedbearsas/claude-craft/docker-hadolint
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add TheBeardedBearSAS/claude-craft --skill docker-hadolint
Clone the repo
git clone --depth 1 https://github.com/TheBeardedBearSAS/claude-craft

Made for: Claude Code.

Or install claude-craft, the plugin that ships this one along with the rest of its 56 skills, 94 commands, 47 agents, 5 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for docker-hadolint

README.md
[![agentmods](https://agentmods.dev/badge/skills/thebeardedbearsas/claude-craft/docker-hadolint/github.svg)](https://agentmods.dev/skills/thebeardedbearsas/claude-craft/docker-hadolint)
Your own site
<a href="https://agentmods.dev/skills/thebeardedbearsas/claude-craft/docker-hadolint"><img src="https://agentmods.dev/badge/skills/thebeardedbearsas/claude-craft/docker-hadolint/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for docker-hadolint

Your own site · 80×15
<a href="https://agentmods.dev/skills/thebeardedbearsas/claude-craft/docker-hadolint"><img src="https://agentmods.dev/badge/skills/thebeardedbearsas/claude-craft/docker-hadolint.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 28 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 594 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 2 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium MCP Rug Pull · line 24
    Docker image references without a specific tag (:latest is implicit) or digest (@sha256:...) can be silently replaced by a malicious image.
    Fix: Pin the image: image:tag or image@sha256:abc123
  • low Tool Misuse · line 24
    Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).
    Fix: Validate all tool parameters against an allowlist. Reject dangerous parameter values (shell=True, --force, -rf /) and use safe defaults.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00028 $0.00594
Opus 5 $0.00014 $0.00297
Sonnet 5 $0.00006 $0.00119
Haiku 4.5 $0.00003 $0.00059

Measured 6d ago against content hash f70602eb9a50, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

docker-hadolint scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/docker-hadolint/SKILL.md · 70 lines

What it actually says

Docker & Hadolint (2026)

Versions (avril 2026)

Validation Hadolint

TOUJOURS utiliser la version pinnée v2.12.0 (jamais latest ou sans tag).

# Validation Dockerfile
docker run --rm -i hadolint/hadolint:v2.12.0 < Dockerfile

# Validation via Makefile (recommandé)
make hadolint

Best Practices 2026

BuildKit Cache Mounts

RUN --mount=type=cache,target=/var/cache/apk \
    apk add --no-cache postgresql-dev

Bénéfice : Réduction temps build de 40-60%
Source : https://docs.docker.com/build/cache/

BuildKit Secrets

RUN --mount=type=secret,id=composer_token \
    COMPOSER_AUTH="$(cat /run/secrets/composer_token)" composer install

Bénéfice : Aucun secret dans l'image finale
Source : https://docs.docker.com/build/building/secrets/

Multi-Stage Builds

FROM php:8.4-fpm-alpine AS builder
RUN composer install

FROM php:8.4-fpm-alpine AS runtime
COPY --from=builder /app /app

Bénéfice : Réduction taille image de 60-97%
Source : https://docs.docker.com/build/building/multi-stage/

Images Distroless

FROM gcr.io/distroless/php8.4-fpm
COPY --from=builder /app /app

Bénéfice : Surface d'attaque minimale, CVE réduites de 90%
Source : https://github.com/GoogleContainerTools/distroless

Documentation Complète

Voir @.claude/references/symfony/docker.md pour architecture complète et exemples.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 70 lines · 28 tokens per session scan A f70602eb9a50

Subscribe to this mod's changes

docker-hadolint is a skill published in the GitHub repository TheBeardedBearSAS/claude-craft (105 stars, last pushed 7d ago), licensed MIT. It adds 28 tokens to every session and 594 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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