dockerfile-hardening SKILL.md skillA
dockerfile-hardening from hermeticormus/libresecops-claude-code is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add hermeticormus/libresecops-claude-code/dockerfile-hardening@git:20260930.71a2663Pins git:20260930.71a2663 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- hermeticormus/libresecops-claude-code
- Path
plugins/container-security/skills/dockerfile-hardening/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260930.71a2663, committed Sep 30, 2026
- First version recorded
- Feb 25, 2026
- Size
- 8,671 bytes
- Repository stars
- 4
- License
- MIT
Secure Dockerfile patterns: base image hierarchy, multi-stage builds for Node.js and Go on distroless or scratch, BuildKit secret mounts, and non-root execution. Use when writing or reviewing a Dockerfile.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Dockerfile Hardening > Secure Dockerfile patterns, multi-stage builds, minimal base images, and build-time security practices. ## Knowledge Base ### Container Image Security Model A container image is a stack of filesystem layers. Each Dockerfile instruction creates a layer. Security implications: - **Layers are permanent.** Even if you `RUN rm /secret` in a later layer, the file exists in the layer where it was created. Anyone with `docker history` or `dive` can extract it. - **Layers are shared.** If two images share a base, they share layers. A vulnerability in the base affects all derived images. - **The build context is sent to the daemon.** Without `.dockerignore`, your entire directory (including `.env`, `.git`, `node_modules`) is sent to the Docker daemon. ### Base Image Hierarchy (Most to Least Secure) | Base | Size | Packages | Debug Tools | Use Case | |------|------|----------|-------------|----------| | `scratch` | 0 MB | None | None | Statically compiled Go/Rust binaries | | `gcr.io/distroless/*` | 2-20 MB | Runtime only (glibc, libssl) | None | Java, Python, Node.js runtimes | …
Read the whole file at its exact version.
How to install
mdr add hermeticormus/libresecops-claude-code/dockerfile-hardening@sha256:7d5d73687a247352The line at the top of this page pins the label git:20260930.71a2663, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_d22hqy66tkbu4gdm)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Feb 25, 2026 and Sep 30, 2026, about one every 218 days. Its first recorded version is graded C and its latest A.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260930.71a2663 latest | 2026-09-30 | 71a2663 | 8,671 B | A | view · diff |
| git:20260225.4a0a620 | 2026-02-25 | 4a0a620 | 8,412 B | C | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (8671 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
hermeticormus/libresecops-claude-code · 4 stars · license MIT · pushed 2026-10-04 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_d22hqy66tkbu4gdm GET https://markdownregistry.com/api/v1/resolve?ref=hermeticormus/libresecops-claude-code/dockerfile-hardening GET https://markdownregistry.com/api/v1/blob/7d5d73687a2473525f7260de1a1a25c0ae55cb3c41347d203bb07e2b248f1986
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.