docker

docker is a skill for Claude Code, Codex from neverinfamous/memory-journal-mcp. It costs 108 tokens per session (1,523 once invoked), scanned C, original, MIT.

A set of standards for building Docker containers, which package an application and its dependencies into a portable runtime environment. It covers Dockerfiles and Docker Compose setups.

In plain words
What is it for?
Use it when writing Dockerfiles, creating multi-stage builds, configuring Compose environments, or preparing images for a container registry.
Why use it?
It helps produce smaller, repeatable, and more secure container images while avoiding common deployment mistakes.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/neverinfamous/memory-journal-mcp/docker
Any agent
npx skills add neverinfamous/memory-journal-mcp --skill docker
Clone the repo
git clone --depth 1 https://github.com/neverinfamous/memory-journal-mcp

Made for: Claude Code, Codex.

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

README.md
[![agentmods](https://agentmods.dev/badge/skills/neverinfamous/memory-journal-mcp/docker.svg)](https://agentmods.dev/skills/neverinfamous/memory-journal-mcp/docker)
Your own site
<a href="https://agentmods.dev/skills/neverinfamous/memory-journal-mcp/docker"><img src="https://agentmods.dev/badge/skills/neverinfamous/memory-journal-mcp/docker.svg" alt="Measured on agentmods" height="20"></a>
Per session 108 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,523 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 2 findings. Scan, not verified.
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 $0.00108 $0.01523
Opus 5 $0.00054 $0.00762
Sonnet 5 $0.00022 $0.00305
Haiku 4.5 $0.00011 $0.00152

Measured 4d ago against content hash 438f91c1be96, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

docker scanned grade C with 2 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 4d 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.

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

&& rm -rf /var/lib/apt/lists/*

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- **The runtime stage should have ZERO build tools** (no compilers, no git, no curl)
skills/docker/SKILL.md · 169 lines

How it starts

The opening of the file, as written. The whole thing — 169 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Docker & Container Engineering Standards

This skill codifies 2026 Docker best practices — secure, minimal, reproducible container images using BuildKit, multi-stage builds, and Compose v2.

1. Dockerfile Fundamentals

Always Start With BuildKit Syntax

# syntax=docker/dockerfile:1

Place this as the first line of every Dockerfile. It enables:

  • Parallel stage execution
  • Cache mounts (--mount=type=cache)
  • Secret mounts (--mount=type=secret)
  • Reproducible builds across Docker versions

Base Image Selection

Use Case Recommended Base Why
Node.js node:22-slim Debian Slim — small, has essential libs
Python python:3.13-slim Minimal Debian, no build tools
Go scratch or distroless Static binary needs nothing
General debian:bookworm-slim Stable, well-patched, small
  • NEVER use :latest — always pin to a specific version tag
  • Prefer -slim variants over full images to reduce attack surface
  • Consider distroless for production — no shell, no package manager = minimal attack surface

2. Multi-Stage Builds (Required for Production)

Multi-stage builds are mandatory for any production image. They separate build-time dependencies from runtime. See templates.md for the full annotated Multi-Stage Build template.

Key Rules

  • Name every stage: FROM ... AS builder — makes builds readable and targetable
  • Copy only artifacts: Use COPY --from=builder to cherry-pick built files
  • Never install dev dependencies in the runtime stage
  • The runtime stage should have ZERO build tools (no compilers, no git, no curl)

3. Security Hardening

Non-Root Execution (Mandatory)

# Create a system user with no home directory, no login shell
RUN groupadd -r appgroup && useradd -r -g appgroup -s /usr/sbin/nologin appuser

# Switch to the non-root user BEFORE CMD
USER appuser

Read the full file on GitHub · 169 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 4d ago First seen · 169 lines · 108 tokens per session scan C 438f91c1be96

Subscribe to this mod's changes

docker is a skill published in the GitHub repository neverinfamous/memory-journal-mcp (20 stars, last pushed 1mo ago), licensed MIT. It adds 108 tokens to every session and 1,523 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it C with 2 findings (recursive force delete, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.