docker-containerization

A guide for packaging an application in Docker, a system that runs software in isolated, repeatable containers. It covers Dockerfiles and Docker Compose setups for Python, Node.js, and multi-service applications.

In plain words
What is it for?
Use it to create or improve Dockerfiles, set up local API-and-database environments, add non-root users and health checks, and optimize build files.
Why use it?
It provides a consistent development and deployment environment while addressing image size and basic security concerns. It also helps keep unnecessary files out of builds and makes service health visible.

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/bdiasti/maestro-bundle-cli/docker-containerization
Any agent
npx skills add bdiasti/maestro-bundle-cli --skill docker-containerization
Clone the repo
git clone --depth 1 https://github.com/bdiasti/maestro-bundle-cli

Made for: Claude Code, Codex.

Per session 38 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,719 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 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 $0.00038 $0.01719
Opus 5 $0.00019 $0.00860
Sonnet 5 $0.00008 $0.00344
Haiku 4.5 $0.00004 $0.00172

Measured 2d ago against content hash 6dfbf934728c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

docker-containerization scanned grade B 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 2d 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 deletemediumDestructive command

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

RUN apt-get update && apt-get install -y --no-install-recommends gcc && rm -rf /var/lib/apt/lists/*

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Makes network callslowCapability

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

HEALTHCHECK --interval=30s --timeout=5s CMD curl -f http://localhost:8000/health || exit 1
templates/bundle-ai-agents/skills/docker-containerization/SKILL.md · 224 lines

How it starts

The opening of the file, as written. The whole thing — 224 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Docker Containerization

Build production-ready Docker images with multi-stage builds, non-root users, health checks, and docker-compose configurations for local development.

When to Use

  • Containerizing a Python (FastAPI/Django) or Node.js (React/Next.js) application
  • Creating or optimizing a Dockerfile
  • Setting up docker-compose for local development
  • Adding health checks, security hardening, or image size optimization
  • Configuring multi-service development environments (API + DB + Redis + MinIO)

Available Operations

  1. Create multi-stage Dockerfiles for Python applications
  2. Create multi-stage Dockerfiles for React/Node.js applications
  3. Configure docker-compose for development
  4. Add security hardening (non-root user, minimal base image)
  5. Add health checks for container orchestration
  6. Create .dockerignore for build optimization

Multi-Step Workflow

Step 1: Create .dockerignore

Always start with .dockerignore to prevent unnecessary files from entering the build context.

.git
node_modules
__pycache__
*.pyc
.env
.venv
dist
build
coverage
.pytest_cache

Step 2: Create the Dockerfile (Python)

Use multi-stage build for minimal image size.

# === Build stage ===
FROM python:3.11-slim AS builder
WORKDIR /app
RUN apt-get update && apt-get install -y --no-install-recommends gcc && rm -rf /var/lib/apt/lists/*
COPY requirements.txt .
RUN pip install --no-cache-dir --prefix=/install -r requirements.txt

# === Runtime stage ===
FROM python:3.11-slim
WORKDIR /app
RUN groupadd -r appuser && useradd -r -g appuser appuser
COPY --from=builder /install /usr/local
COPY src/ ./src/
USER appuser
EXPOSE 8000
HEALTHCHECK --interval=30s --timeout=5s CMD curl -f http://localhost:8000/health || exit 1
CMD ["uvicorn", "src.main:app", "--host", "0.0.0.0", "--port", "8000"]

Step 3: Create the Dockerfile (React)

FROM node:20-slim AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build

FROM nginx:alpine
COPY --from=builder /app/dist /usr/share/nginx/html
COPY nginx.conf /etc/nginx/conf.d/default.conf
EXPOSE 80

Read the full file on GitHub · 224 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. 2d ago First seen · 224 lines · 38 tokens per session scan B 6dfbf934728c

Subscribe to this mod's changes

docker-containerization is a skill published in the GitHub repository bdiasti/maestro-bundle-cli (21 stars, last pushed 5mo ago), licensed MIT. It adds 38 tokens to every session and 1,719 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B 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.

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