container-layer SKILL.md skillA
This file is byte-identical to the first copy the registry indexed. Same content hash, so the same checks give both the same grade.
container-layer from oaustegard/claude-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add oaustegard/claude-skills/container-layer@v0.4.0Pins v0.4.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- oaustegard/claude-skills
- Path
container-layer/SKILL.md- Versions recorded
- 5
- Latest version
- v0.4.0, committed Aug 25, 2026
- First version recorded
- May 17, 2026
- Size
- 5,794 bytes
- Repository stars
- 158
- License
- MIT
Authors and caches a personalized container environment from a Dockerfile- like spec, as a single layer or as a composition of independently cached layers. Use when the user mentions "container layer", "Containerfile", "custom container", "cache my installs", "composable layers", "uv shim", or wants package installations, skills and environment config to survive an ephemeral session. Also for snapshotting, restoring or rebuilding that environment, and for capturing ad-hoc installs into a…
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
# Container Layer Build a reproducible, cached environment overlay for ephemeral containers using a Dockerfile-like spec. ## When NOT to use this skill This authors and caches a layer spec. It is not a Docker troubleshooting tool. | Situation | Use | |---|---| | A build is slow or failing | read the build log; this skill will not help | | Managing a running container | docker/podman directly | | Session boot sequence and hooks | the workspace's own boot docs | The tell is tense: this skill is for the environment you want next session, not the container you are fighting now. ## Concept The container resets every session, but your environment shouldn't. This skill: 1. Parses a `Containerfile` (Dockerfile subset) that declares your environment 2. Caches the built result as a tarball in GitHub Releases 3. Restores from cache on subsequent boots (single fetch vs. N installs) 4. Provides a `uv` shim that captures ad-hoc installs back into the Containerfile ## Supported Containerfile Instructions ```dockerfile # Environment variables ENV KEY=value # Shell commands (including package installs) RUN apt-get install -y foo # system packages …
Read the whole file at its exact version.
How to install
mdr add oaustegard/claude-skills/container-layer@sha256:6708e792ebe9a902The line at the top of this page pins the label v0.4.0, 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_icr44ggdnzceertl)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 5 versions of this file, between May 17, 2026 and Aug 25, 2026, about one every 25 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v0.4.0 latest | 2026-08-25 | 4fcc13f | 5,794 B | A | view · diff |
| v0.2.3 | 2026-08-25 | 9b9c991 | 5,490 B | A | view · diff |
| v0.2.2 | 2026-05-17 | bad5812 | 5,490 B | A | view · diff |
| v0.2.1 | 2026-05-17 | 179ee74 | 5,490 B | A | view · diff |
| v0.2.0 | 2026-05-17 | 79d4c38 | 5,490 B | A | 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 (5794 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
oaustegard/claude-skills · 158 stars · license MIT · pushed 2026-11-07 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_icr44ggdnzceertl GET https://markdownregistry.com/api/v1/resolve?ref=oaustegard/claude-skills/container-layer GET https://markdownregistry.com/api/v1/blob/6708e792ebe9a90282f6012586dc19561b6664e4ab55053c47557b0150bef76b
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.
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