docker-extend

docker-extend is a skill for Claude Code, Codex from coleam00/Archon. It costs 118 tokens per session (1,066 once invoked), scanned C, original, MIT.

Use when: User wants to extend Docker with custom tools, personalize the Docker environment, or set up user-specific Docker customization. Triggers: 'extend docker', 'docker-extend', 'add tools to docker', 'customize docker', 'add my tools to the container', 'personalize docker setup', 'docker user setup', 'install…

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/coleam00/archon/docker-extend
Any agent
npx skills add coleam00/Archon --skill docker-extend
Clone the repo
git clone --depth 1 https://github.com/coleam00/Archon

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-extend

README.md
[![agentmods](https://agentmods.dev/badge/skills/coleam00/archon/docker-extend.svg)](https://agentmods.dev/skills/coleam00/archon/docker-extend)
Your own site
<a href="https://agentmods.dev/skills/coleam00/archon/docker-extend"><img src="https://agentmods.dev/badge/skills/coleam00/archon/docker-extend.svg" alt="Measured on agentmods" height="20"></a>
Per session 118 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,066 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 1 finding. 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 $0.00118 $0.01066
Opus 5 $0.00059 $0.00533
Sonnet 5 $0.00024 $0.00213
Haiku 4.5 $0.00012 $0.00107

Measured yesterday against content hash a3836506c0d4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

docker-extend scanned grade C with 1 finding 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 yesterday.

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/*
.claude/skills/docker-extend/SKILL.md · 108 lines

How it starts

The opening of the file, as written. The whole thing — 108 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Docker Extend

Sets up personal Docker tool customization using the project's gitignored override pattern. Your Dockerfile.user and docker-compose.override.yml are yours — never committed to git.

Step 1: Detect Context

Determine if the user is in dev (source build) or deploy (GHCR) mode:

!if [ -f docker-compose.yml ] && grep -q 'build: \.' docker-compose.yml 2>/dev/null; then echo "DEV_MODE: Building from source (root docker-compose.yml)"; elif [ -f deploy/docker-compose.yml ]; then echo "DEPLOY_MODE: Using GHCR image (deploy/docker-compose.yml)"; else echo "UNKNOWN_MODE: No docker-compose.yml found in root or deploy/"; fi

Decision:

  • DEV_MODE → work with Dockerfile.user + docker-compose.override.yml (repo root)
  • DEPLOY_MODE → work with deploy/Dockerfile.user + deploy/docker-compose.override.yml
  • UNKNOWN_MODE → ask the user which directory their docker-compose.yml lives in before proceeding

Step 2: Check Current State

DEV_MODE — check root files:

!echo "=== Dockerfile.user ===" && (cat Dockerfile.user 2>/dev/null || echo "(not found — will create from example)") && echo "" && echo "=== docker-compose.override.yml ===" && (cat docker-compose.override.yml 2>/dev/null || echo "(not found — will create from example)")

DEPLOY_MODE — check deploy/ files:

!echo "=== deploy/Dockerfile.user ===" && (cat deploy/Dockerfile.user 2>/dev/null || echo "(not found — will create from example)") && echo "" && echo "=== deploy/docker-compose.override.yml ===" && (cat deploy/docker-compose.override.yml 2>/dev/null || echo "(not found — will create from example)")

If both files already exist: Skip to Step 4 (add tools). If files are missing: Proceed to Step 3 (copy from examples). If example files are missing too: Tell the user the project hasn't added the example files yet and to check with the maintainers or the docs.

Step 3: Copy Example Files

Run only the copy commands for whichever files are missing. Do NOT overwrite existing files.

Read the full file on GitHub · 108 lines

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. yesterday First seen · 108 lines · 118 tokens per session scan C a3836506c0d4

Subscribe to this mod's changes

docker-extend is a skill published in the GitHub repository coleam00/Archon (23,366 stars, last pushed yesterday), licensed MIT. It adds 118 tokens to every session and 1,066 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it C with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-02.